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  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s Table of Content s • • I ndex • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By By Cisco Systems, Inc. Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 Pages: 11 28 Copy right

  I SBN: 1- 58 705 -1 19 -2

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  I con s Used in Th is Book essent ial an d cu t t ing- edg e t ech nologies. Com man d Sy nt ax Conv ent ions I n tr oduct ion

  Object iv es

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  Upd ates t o t h e Fourt h Edit ion nov ice t o ex pert . Audience

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  Organizat ion Ack nowledgmen ts an d Con t ribut ors

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Thir d Edit ion Con t ribut ors First Edition Con t ribut ors

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  Part I . I nt rodu ction t o I nt ern et work ing I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Cha pter 1. I nt ern et work ing Basics

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

  What I s an I nt ernet work ?

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  Open Sy st em I nt ercon nect ion Ref erence Model indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . I n form at ion Fo rmat s

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  I SO Hierarchy of Networ ks

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all

  Con nect ion-Orient ed and Conn ect ion less Net work Serv ices net w or kin g p rof essionals, r egar dless of ex pert ise. I n tern et wor k Addressing

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  Flow Con t rol Basics

  har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on

  Er ror-Ch eck in g Basics

  a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Mu ltiplexing Basics t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . St andards Organiza tion s

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  Sum mar y

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

  Rev iew Qu est ion s

  pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  For More I nfo rmat ion

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Cha pter 2. I nt rod uct ion t o LAN Pr oto cols What I s a LAN? LAN Prot ocols and t he OSI Ref erence Model LAN Media- Access Met ho ds

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  LAN Topologies LAN Dev ices Rev iew Qu est ion s For More I nfo rmat ion Cha pter 3. I nt rod uct ion t o WAN Techn olo gies What I s a WAN? Point - t o-Poin t Lin ks Circu it Swit ch ing Pack et Swit ching WAN Virt u al Circu it s WAN Dialup Services WAN Dev ices Rev iew Qu est ion s For More I nfo rmat ion Cha pter 4. I nt rod uct ion t o Cisco I OS Soft ware System Arch itect u re Cisco I OS CLI Deb ugging and Lo gging Reloading and Upgr ading Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 5. Bridging and Swit ch ing Basics What Ar e Bridges an d Swit ches? Lin k La yer Dev ice Ov er view Ty pes of Bridges Ty pes of Swit ches Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 6. Rout ing Basics What I s Rout ing? Rou tin g Com pon en t s Rou tin g Algorit hm s Net work Prot ocols Rev iew Qu est ion s

  Cha pter 7. Net work Managem en t Basics I n tr oduct ion What I s Net work Man agemen t? Net work Managem ent Arch itect u re

  I SO Net work Manag em ent Model Rev iew Qu est ion s

  Part I I . LAN Prot ocols Cha pter 8. Et hern et Techn ologies Back groun d Et h er net —A Br ief Histo ry Et h er net Net work Element s Et h er net Net work Topologies an d St ructu res The I EEE 802 .3 Logical Relat ionsh ip t o t he I SO Ref er en ce Mo del

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  System Con siderat ions Sum mar y Rev iew Qu est ion s

  Cha pter 9. Fib er Dist ribut ed Dat a I nt erface I n tr oduct ion FDDI Tran smission Media FDDI Specif icat ions FDDI Stat ion -At t achm en t Ty pes FDDI Fault Toleran ce FDDI Frame Fo rmat Copper Dist ribu t ed Dat a I n t erf ace Sum mar y Rev iew Qu est ion s

  Part I I I . WAN Tech nologies Cha pter 10 . Fram e Relay I n tr oduct ion Fram e Relay Dev ices Fram e Relay Virt ual Circuit s Con gest ion -Con t rol Mech anism s Fram e Relay Local Man agemen t I nt erf ace Fram e Relay Net work I mplemen ta tion Fram e Relay Fram e Format s Sum mar y Rev iew Qu est ion s Cha pter 11 . Hig h-Speed Serial I nt erface I n tr oduct ion HSSI I nt erface Basics HSSI Operat ion Sum mar y Rev iew Qu est ion s Cha pter 12 . I n t egr at ed Ser vices Digit al Net work I n tr oduct ion I SDN Dev ices Ser vices I SDN Specif ication s Sum mar y Rev iew Qu est ion s Cha pter 13 . Poin t -t o-Po in t Pro tocol I n tr oduct ion PPP Comp onent s Gen eral Operat ion Phy sical Lay er Requ irement s PPP Link Lay er PPP Link- Cont rol Prot ocol Sum mar y Rev iew Qu est ion s Cha pter 14 . Swit ched Mult imegabit Dat a Ser vice I n tr oduct ion

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Dist ribut ed Queue Du al Bus SMDS Access Classes SMDS Addressing Overv iew SMDS Reference: SI P Lev el 3 PDU Form at SMDS Reference: SI P Lev el 2 Cell Forma t Sum mar y Rev iew Qu est ion s

  Cha pter 15 . Dialup Techn olo gy I n tr oduct ion A Shor t Dialu p Tech nology Backgr ound Dialup Connect iv it y Techn ology Dialup Meth ods Ben efit s and Dra wback s Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 16 . Sy nch ronou s Dat a Link Cont rol and Deriv at ives I n tr oduct ion SDLC Ty pes and Topologies SDLC Fram e Form at Der iv at ive Prot oco ls Sum mar y Rev iew Qu est ion s

  Cha pter 17 . X.2 5 I n tr oduct ion X.2 5 Dev ices an d Pro tocol Operat ion The X. 25 Pr oto col Suit e LAPB Fram e Form at X.1 21 Address For mat Sum mar y Rev iew Qu est ion s

  Cha pter 18 . Virt ual Priv at e Net work s ( VPNs)

  VPN Def init ion

  VPN App lica tion s

  I PSec La yer 2 Tun nelin g Prot ocol ( L2 TP) MPLS VPNs Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Part I V. Mu lt iserv ice Access Techn ologies Cha pter 19 . Voice/ Dat a I nt egrat ion Techno log ies I n tr oduct ion Advances in Applicat ions New World Voice Tech nologies Voice Net work ing Voice ov er ATM Voice ov er Fram e Relay

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Gen eral MGCP Overv iew Gen eral SI P Tut orial Skin ny Client Cont rol Prot ocol (SCCP) Com parison an d Con tr ast of t h e Various VoI P Signa lin g Alt er nat ives Evolu tion of Solut ion s f or Voice over Dat a Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 20 . Wireless Tech nologies Wireless Con cepts Radio Fu ndam ent als NLOS Wireless: Ov ercomin g Mult ipat h Sign als in NLOS High Speed Spread Spect rum Elem en t s of a Tot al Netwo rk Solut ion Wireless Local-Area Networ ks ( WLANs) Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Glossary Term s

  Cha pter 21 . Digit al Subscriber Lin e I n tr oduct ion Asy mm etr ic Digita l Subscr iber Lin e Signaling and Modu lat ion Addit io nal DSL Techn ologies Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 22 . Cable Access Techn ologies I n tr oduct ion Ev olu tion f rom One-Way Br oadcast to Two- Way Hy brid Fiber Coax Lim it at io ns and Specif icat ions of t he HFC Plant DOCSI S St an dards, Signaling Prot ocols, and Applicat ion s DOCSI S Hardware Deploy m en t an d Result ing Service Capabilit ies Fut ur e DOCSI S Applicat ions Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 23 . I n t roduct ion t o Opt ical Techno lo gies What I s Opt ical Net work in g? Gen eralized Mu lt ipr ot ocol Label Switching G.ASON Opt ical Con tr ol Plan e User Net work I n t er face Opt ical Con tr ol Plan e Op tical Net work -t o- Net work I n t er face Nex t -Generat ion Prot ect ion and Restor at ion Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 24 . VoI P

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Session I nit iat ion Prot ocol ( SI P) Con nect ing VoI P Net work s with t h e SS7 Net work Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Glossary Term s Cha pter 25 . Dy nam ic Packet Transpor t/ Spat ial Reuse Prot ocol DPT Arch itect u re SRP Ban dwidth Opt imiza tion SRP Pa cket Priorit y SRP Fairn ess Algorit hm DPT Resiliency Topology Disco very DPT/ SRP Pack et Forma ts SRP Version 2 Gen eric Header SRP Dat a Pack et SRP Con t rol Pa cket Mu ltica st Suppor t Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Glossary Term s Cha pter 26 . Ext ensible Au t hent icat ion Prot ocol (EAP) The EAP Prot ocol Usin g RADI US for EAP Au t hent icat ion A Ty pical Au t hent icat ion Conv ersat ion PKI Su pport wit h EAP EAP I mp lem ent at ions Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Part V. Bridging and Swit ch ing Cha pter 27 . Tra nsparen t Bridging Tran sparent Br id gin g Operat ion Fram e Forma t Rev iew Qu est ion s For More I nfo rmat ion Cha pter 28 . Mix ed- Media Bridging Back groun d Tran slat ion Challenges Tran slat ional Bridgin g Source- Rout e Tr anspar en t Bridging Rev iew Qu est ion s For More I nfo rmat ion Cha pter 29 . Sour ce- Rout e Bridg in g Back groun d SRB Algorit hm Fram e Forma t

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Cha pter 30 . LAN Swit chin g an d VLANs Hist ory LAN Switch Operat ion LAN Switch and th e OSI Model Rev iew Qu est ion s For More I nfo rmat ion Cha pter 31 . Asy nch ronou s Transf er Mode Swit ching St andards ATM Dev ices an d t h e Net work Env ironm ent ATM Cell Header Form at ATM Serv ices ATM Swit ch in g Operat ions ATM Ref erence Model ATM Add ressing ATM Conn ect ion s ATM and Mult icast ing ATM Qu ality of Serv ice ATM Sign aling and Conn ect ion Est ablishm en t ATM Conn ect ion -Ma nagemen t Messages PNNI I n tegrat ed Local Man agement I nt erfa ce LAN Em ulat ion Mu ltipr oto col ov er ATM Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 32 . MPLS MPLS Term inology MPLS Operat ions MPLS/ Tag- Swit ch ing Archit ectu re Hierarchical Ro ut ing MPLS-Based Virt ual Priv at e Net work s MPLS Qualit y of Serv ice MPLS Traf fic En gineering Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 33 . Dat a-Link Swit chin g Back groun d DLSw Con t rast ed wit h Source- Rout e Bridging DLSw SNA Su pport DLSw Swit ch- t o-Swit ch Prot ocol DLSw Operat ion DLSw Message Form at s Rev iew Qu est ion s

  Part VI . Net work Prot ocols Cha pter 34 . Open Sy st em I n terco nnect ion Prot ocols Back groun d OSI Net work ing Prot ocols

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Back groun d I n tern et Prot ocol Address Reso lu t ion Prot ocol Ov erv iew I n tern et Rout ing I n tern et Cont rol Message Prot ocol Tran smissio n Co nt rol Prot ocol User Dat agram Prot ocol I n tern et Prot ocols Application Lay er Prot oco ls Sum mar y Rev iew Qu est ion s Cha pter 36 . I Pv6 Descript ion of I Pv 6 Pack et Header Hex adecimal "Hex " Addressing Descript io n Broadcast in g Met ho ds Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 37 . Net Ware Prot ocols Back groun d Net Ware Med ia Access I n tern et wor k Pack et Ex ch ange Ov erv iew

  I PX Encap sulat ion Types Ser vice Adv ert isemen t Prot ocol Net Ware Tr anspor t Lay er Net Ware Upper-Lay er Prot ocols and Services

  I PX Pack et For mat Sum mar y Rev iew Qu est ion s Cha pter 38 . AppleTalk I n tr oduct ion AppleTalk Net work Com pon en t s AppleTalk Phy sical and Da ta Lin k Lay ers Net work Addr esses AppleTalk Address Resolu t ion Pr ot ocol Dat agram Deliv ery Pr oto col Ov erv iew AppleTalk Tran sport Lay er AppleTalk Upper- Lay er Prot ocols AppleTalk Prot ocol Su it e Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 39 . I BM System s Networ k Archit ect ure Prot ocols Back groun d Tradit iona l SNA Env ironm ent s

  I BM Peer- Based Net work ing Basic I nf ormat ion Unit Form at Pat h I nf orm at ion Unit For mat

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  For More I nfo rmat ion Cha pter 40 . DECn et I n tr oduct ion

  DECn et Phase I V Digital Net work Arch itect u re DECn et / OSI Digit al Netwo rk Archit ect ure DECn et Media Access DECn et Rout ing DECn et End Com mu nicat ions Layer DECn et / OSI Transport Layer DECn et Phase I V Upp er Lay ers DECn et / OSI Upper Lay ers Sum mar y Rev iew Qu est ion s

  Part VI I . Rou t ing Prot ocols Cha pter 41 . Border Gat eway Prot ocol I n tr oduct ion BGP At tr ib ut es BGP Pat h Select ion Rev iew Qu est ion s For More I nfo rmat ion Cha pter 42 . Enha nced I GRP En han ced I GRP Capabilities and Att ribu t es Un derlyin g Pr ocesses an d Tech nologies Rou tin g Con cept s En han ced I GRP Pack et Ty pes Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 43 . I BM System s Networ k Archit ect ure Rout ing Back groun d I BM SNA Session Conn ect or s I BM SNA Tran smissio n Grou ps I BM SNA Ex plicit an d Virt ua l Rout es I BM SNA Class of Ser vice I BM SNA Subarea Rout ing I BM Ad van ced Peer-t o- Peer Net work ing Rou tin g Rev iew Qu est ion s Cha pter 44 . I n t er io r Gat eway Rout in g Prot ocol Back groun d I GRP Prot ocol Ch aract erist ics Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 45 . I n t er net Prot oco l Mu lticast Back groun d Mu ltica st Group Concept I P Mult icast Ad dresses I n tern et Group Man agem ent Prot ocol

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Mu ltica st Forwardin g Prot ocol- I ndepend en t Mu ltica st Mu ltipr oto col Border Gat eway Pr ot ocol Mu ltica st Source Discovery Prot ocol Rev iew Qu est ion s For More I nfo rmat ion Cha pter 46 . Net Ware Link - Serv ices Pr ot ocol Back groun d NLSP Hierar chical Rout ing NLSP Operat ion NLSP Hierar chical Addr essin g NLSP Hello Pack et s Rev iew Qu est ion s

  Cha pter 47 . Open Sh ort est Pat h First Back groun d Rou tin g Hierar chy SPF Algorit hm Pack et Form at Addit io nal OSPF Feat ures Rev iew Qu est ion s Cha pter 48 . Open Sy st em I n terco nnect ion Rout in g Prot ocols OSI Net work ing Term in ology Overv iew of OSI Rout ing Operat ion ES- I S

  I S-I S

  I S-I S LSP Processing

  I DRP Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 49 . Rou t in g I nf ormat ion Pro tocol Back groun d Rou tin g Updat es RI P Rout ing Met ric RI P Stab ilit y Feat ures RI P Timers Pack et Form at s Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 50 . Resou rce Reserv at ion Prot ocol Back groun d RSVP Dat a Flows RSVP Qualit y of Serv ice RSVP Session St art u p RSVP Reserv at io n St y le RSVP Soft St at e I mplem en t at ion RSVP Operat ional Model

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Cha pter 51 . Simp le Mult icast Rout ing Prot ocol I n tr oduct ion SMRP Mult icast Transport Serv ices SMRP Transact io n Example SMRP Pack et Forma t Rev iew Qu est ion s

  Part VI I I . Networ k Man agement Cha pter 52 . Securit y Tech nologies Why I s Networ k Secu rit y I m port ant ? Securit y Th reats Securit y Policy Def ense-in -Dept h Secu rity Solu t io n Thr eat Mit igat ion Securit y Tools Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Glossary Term s Cha pter 53 . Direct ory -Enabled Net wor kin g Object -Orient ed I nf orma tion Modelin g A Brief I nt rod uct ion t o Direct ories An Ov erv iew of DEN How DEN I s Used in Cisco Prod uct s Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 54 . Net work Cachin g Tech nologies I n tr oduct ion Net work Caching En surin g Fresh Con ten t Rev iew Qu est ion s Cha pter 55 . St orage Netwo rkin g What I s a SAN? Fibre Ch annel Prot ocol The iSCSI Prot ocol Sum mar y Rev iew Qu est ion s For More I nfo rmat ion Cha pter 56 . I BM Net work Managem ent Back groun d I BM Net work -Ma nagemen t Fun ct ion al Areas I BM Net work -Ma nagemen t Archit ect ures I BM Net work -Ma nagemen t Plat for ms Rev iew Qu est ion s Cha pter 57 . Rem ot e Mon itor in g

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Rev iew Qu est ion s Cha pter 58 . Simp le Net work Ma nagemen t Prot ocol SNMP Basic Co mpon en t s

  Basic SNMP Co mm ands SNMP Man agement I nf orm at ion Base SNMP and Dat a Represent at ion SNMP Ver sion 1 SNMP Ver sion 2 SNMP Ver sion 3 SNMP Man agement SNMP Reference: SNMP Message Form at s Sum mar y Rev iew Qu est ion s

  Cha pter 59 . Qualit y of Serv ice Net work ing I n tr oduct ion QoS Con cept s Basic QoS Arch it ect u re QoS I dent if icat io n a nd Mark ing QoS Wit hin a Sing le Net work Elem ent QoS Man agement En d-t o- En d QoS Lev els Modu lar QoS Comm and- Lin e I nt erf ace ( MQC) QoS Archit ect ures Con gest ion -Ma nagemen t Tools Queue Managem ent ( Congest ion -Avo id ance To ols) Traf fic- Shaping and Policing Tools Lin k Ef ficiency Mecha nism s QoS Man agement QoS on Et h er net Mu ltipr oto col Label Switch ing (MPLS): Allowing Flex ible Traf fic En gineering SNA ToS QoS f or Packet ized Voice QoS f or St reamin g Video Aut om at ed QoS Sum mar y Rev iew Qu est ion s For More I nfo rmat ion

  Part I X. Appendix Appendix A. An swers t o Review Qu est ion s Cha pter 1 Cha pter 2 Cha pter 3 Cha pter 4 Cha pter 5 Cha pter 6 Cha pter 7 Cha pter 8 Cha pter 9

  • Table of Content s
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  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Cha pter 12 Cha pter 13 Cha pter 14 Cha pter 15 Cha pter 16 Cha pter 17 Cha pter 18 Cha pter 19 Cha pter 20 Cha pter 21 Cha pter 22 Cha pter 23 Cha pter 24 Cha pter 25 Cha pter 26 Cha pter 27 Cha pter 28 Cha pter 29 Cha pter 30 Cha pter 31 Cha pter 32 Cha pter 33 Cha pter 34 Cha pter 35 Cha pter 36 Cha pter 37 Cha pter 38 Cha pter 39 Cha pter 40 Cha pter 41 Cha pter 42 Cha pter 43 Cha pter 44 Cha pter 45 Cha pter 46 Cha pter 47 Cha pter 48 Cha pter 49 Cha pter 50 Cha pter 51 Cha pter 52 Cha pter 53 Cha pter 54 Cha pter 55 Cha pter 56 Cha pter 57 Cha pter 58 Cha pter 59

  Xer ox Net work Sy st ems Bany an VI NES I n dex

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Copyright Cop yr igh t © 200 4 Cisco Sy st ems, I n c.

  Cisco Pr ess log o is a t rad em ar k of Cisco Sy st em s, I nc.

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  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

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  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat pr ogr am s t h at m ay accomp any it .

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The op inions ex pr essed in t his b ook belong t o t he aut hor s and ar e not necessarily t h ose of Cisco indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Sy st em s, I nc. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

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  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e All t er ms ment ion ed in t his b ook t hat ar e kn ow n t o be t rad em ar k s or serv ice mar k s hav e b een har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on app rop riat ely capit alized. Cisco Pr ess or Cisco Syst em s, I nc. cannot at t est t o t he accur acy of t his a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions inf orm at ion. Use of a t er m in t h is book should not be regar ded as af fect in g t he v alid it y of any t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t r adem ark or ser v ice m ar k . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

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  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. how w e cou ld im pr ov e t he qualit y of t h is book , or ot h er w ise alt er it t o bet t er su it y our n eeds, y ou can cont act u s t hr ou gh e- m ail at feedback @ciscopr ess. com . Please mak e sur e t o include t he book t it le and I SBN in y our message. We g reat ly app r eciat e y our assist an ce.

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  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Ar gent ina • Au st r alia • Aust r ia • Belgiu m • Br azil • Bulgar ia • Canad a • Chile • China PRC • t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Colom bia • Cost a Rica • Cr oat ia • Czech Repu blic • D en mar k • Dub ai, UAE • Fin lan d • Fran ce • indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Ger man y • Greece • Hong Kon g SAR • Hu ngar y • I ndia • I nd onesia • I r eland • I sr ael • I t aly • Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Japan • Korea • Lu xem bou rg • Malaysia • Mex ico • The Net h er land s • New Zealand • Nor w ay • and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Peru • Philippines • Poland • Por t ug al • Puert o Rico • Rom ania • Ru ssia • Saud i Ar abia • net w or kin g p rof essionals, r egar dless of ex pert ise.

  Scot land • Sing apor e • Slov ak ia • Slov enia • Sout h Afr ica • Spain • Sw eden • Sw it zerland • Taiw an • Thailand • Tur key • Uk r aine • Un it ed Kingd om • Un it ed St at es • Ven ezu ela • Viet nam • Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Zim babw e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Cop yr igh t © 200 3 Cisco Sy st ems, I n c. All lig ht s r eser v ed . CCI P, CCSP, t h e Cisco Ar row logo, t h e t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cisco Pow ered Net w or k m ar k, t he Cisco Sy st em s Ver ified log o, Cisco Un it y, Follow Me Brow sing , Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Form Sh are, iQ Net Readiness Scorecar d, Net w or king Academ y, and Scr ipt Sh ar e are t r ademar k s syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich of Cisco Sy st em s, I nc. ; Ch angin g t h e Way We W ork , Live, Play , and Lear n, Th e Fast est W ay t o pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease I ncr ease Your I n t ern et Quot ient , and iQuick St ud y ar e ser v ice m ar k s of Cisco Sy st em s, I nc.; and pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Air onet , ASI ST, BPX, Cat aly st , CCDA, CCDP, CCI E, CCNA, CCNP, Cisco, t he Cisco Cer t ified decisions for t h eir net w ork s. I nt er net w ork Ex pert logo, Cisco I OS, t he Cisco I OS logo, Cisco Pr ess, Cisco Sy st ems, Cisco Sy st em s Cap it al, t he Cisco Sy st ems log o, Em p ower ing t he I nt er net Generat ion , En t er p rise/ Solv er , Et h er Ch annel, Et h er Sw it ch, Fast St ep, GigaSt ack , I nt er net Qu ot ien t , I OS,

  I P/ TV, iQ Ex pert ise, t he iQ logo, Light St ream , MGX, MI CA, t h e Net w ork ers log o, Net w ork t r adem ark s of Cisco Sy st em s, I nc. an d/ or it s af filiat es in t he U. S. and cer t ain ot her coun t ries. All ot h er t rad em ar k s m en t ioned in t his d ocum en t or W eb sit e ar e t he p r opert y of t heir respect ive ow ner s. The use of t h e w or d p art ner does not im ply a p art nership r elat ion sh ip b et w een Cisco and any ot her comp any . ( 03 03R) Pr int ed in t h e USA

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Icons Used in This Book

  Cisco uses t he follow in g st an dar d icons t o r epr esent diff erent net w or kin g d ev ices. You w ill encount er sever al of t h ese icons w it hin t h is book .

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Command Syntax Conventions

  The con vent ions used t o pr esent comm an d sy nt ax in t his b ook ar e t he sam e conv ent ions u sed in t he I OS Com m and Refer ence. The Com m and Ref er ence descr ibes t h ese conv en t ions as f ollow s:

  • Table of Content s
  • I ndex Vert ical b ars ( | ) separ at e alt er nat ive, m u t ually exclusive element s.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Squ are br ack et s ( [ ] ) ind icat e an op t ional element . Br aces ( { } ) ind icat e a r eq uir ed choice.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  Br aces w it hin br ack et s ( [ { } ] ) in dicat e a r equir ed ch oice w it hin an opt ional elem en t .

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 Bold

  in dicat es com m ands and key w ord s t hat ar e ent er ed lit er ally as show n . I n conf ig ur at ion ex am ples and out p ut ( not general com m and syn t ax ) , bold indicat es com man ds t h at ar e m anu ally in put by t h e user ( such as a show com m and ) .

  I t alic in dicat es arg um en t s f or w hich y ou supply act u al v alu es.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Introduction Net w ork ing and t h e I n t ern et hav e becom e one of t h e m ost inf lu en t ial f orces in our lives t od ay.

  They cont inu e t o ch ange t he w ay w e w or k, liv e, play , and lear n. I n less t h an t en y ear s, t h e ent ir e w or ld has becom e conn ect ed, mak ing it easy and inex pensiv e t o comm u nicat e arou nd t he

  Table of Content s •

  globe in st ant ly . Few wou ld ar g ue t hat t he I n t ern et has chan ged ev ery asp ect of our lives. I t ' s

  I ndex •

  im pr oved educat ion and m ade t h e w orld' s inf or mat ion av ailable t o an y st udent any w her e,

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  any t im e; it 's how w e com m unicat e w it h our r elat ives; it ' s how w e plan our v acat ions. We now By Cisco Systems, Inc. hav e t h e w orld and it s inf or m at ion at our f inger t ips—creat ing n ew oppor t un it ies f or ever y bu sin ess, gov ern ment , educat ional in st it u t ion, an d in divid ual.

  Pub lish er: Cisco Press

  This b ook seek s t o g ive y ou a f und am en t al un derst an ding of t he d iff er ent con cept s and Pub Dat e: Sep tem ber 1 1, 2 003 t echnologies used in t h e field of n et wor k ing. This book is a comp r eh en siv e r ef erence t h at sur v ey s

  I SBN: 1- 58 705 -1 19 -2

  a n um ber of dif fer en t n et w or k ing t ech nologies, pr ot ocols, an d p arad igm s; legacy t ech nologies

  Pages: 11 28

  ar e included as w ell as t he m ost cu rr ent t ech nologies. I t is our hope at Cisco Pr ess t h at y ou w ill fin d t he f our t h ed it ion of t h is book cur r en t , r elev ant , an d u sef ul, w het her y ou ar e a n et w or k ing engineer or ot h er net w ork ing pr of essional or a bu siness decision - mak er . This book is also helpfu l if you sim ply w ant t o u nder st and m ore ab out t he I nt er net and t he t echnolog ies on w hich it r uns.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Objectives

  This b ook pr ov id es basic t ech nical infor m at ion about t he var ious t echn olog ies u sed in t he f ield of net w or kin g. I t is design ed f or use w it h ot her Cisco Pr ess book s and as a st an dalone r efer en ce t ool.

  Table of Content s • I ndex

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  This b ook is not int ended t o p r ovide all possib le in for m at ion on t he t echnologies cover ed; r at h er ,

  it seeks t o pr ov ide a general over view h ig hlight in g t he m ost r elev ant and im por t ant det ails of each t echnolog y.

  By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Updates to the Fourth Edition

  For t he publicat ion of t he f our t h ed it ion of t h is book , w e hav e ad ded n ew ch apt er s on opt ical net w or kin g, Voice ov er I P ( VoI P) , DPT/ SRT, EAP, st or age n et w or k ing, QoS, and I OS. Th er e ar e also m any u pdat es t o exist ing chapt er s, and t he most relevan t an d cur r ent in for m at ion h as been

  Table of Content s • included w here appr opr iat e.

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Audience

  The I n t er net w or k in g Techn olog ies Han dbook is wr it t en for an yon e w ho wan t s t o und er st and int er net w ork ing . We an t icipat e t hat t he inf or mat ion in t his b ook w ill help y ou assess t he app licabilit y of specif ic t ech nologies in you r net w or king env ir onm en t s and giv e y ou a basic

  Table of Content s • un derst an ding of t he m an y int ern et wor k ing t ech nologies.

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Organization

  This b ook is or ganized in t o t he follow ing nine sect ions:

  • Table of Content s
  • I ndex

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  P ar t V : Bri dgi ng an d S w it chi ng

  — These Ap pendix es pr ov id e answ er s t o r ev iew qu est ions and discu ssion of early t echn olog ies.

  Ap pen dix e s:

  — Discusses secur it y t echnologies, dir ect or y - enabled net w or kin g, n et w or k caching t ech nologies, and st orag e net w or king .

  P ar t V I I I : N e t w ork M a nag em e nt

  — Prov ides ov er v iew infor m at ion on rou t ing pr ot ocols, includin g BGP, Enh anced I GRP, I BM SNA, I GRP, I nt er net Pr ot ocol Mu lt icast , Net War e Lin k- Serv ices, OSPF, OSI RP, r out ing inf or mat ion , r esour ce r eser vat ion , and SMRP.

  P ar t V I I : Rout i ng P rot ocols

  — Cov er s n et w or k in g pr ot ocols, in clud ing OSI P, I P, I Pv6 , Net War e, AppleTalk, I BM SNA, and DECnet .

  P ar t V I : N e t w ork P rot ocol s

  — Discusses br idging an d sw it ching t ech nologies, includin g t r an sp arent br idgin g, m ix ed - media br idging , sour ce- r out e br idging , LAN sw it ch in g and VLANs, ATM, MPLS, and d at a link sw it ching.

  — Prov ides ov er v iew infor m at ion on access net w or kin g t echn olog ies, includ in g voice/ dat a in t eg r at ion , w ir eless, D SL, cable, opt ical, VoI P, DPT/ SRT, and EAP.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  P ar t I V : Mu lt i se rv i ce A cce ss Te chnol ogie s

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  P ar t I I : LAN Prot ocols — Cov er s LAN pr ot ocols and t heir t echnolog ies. P ar t I I I : W AN Technol ogi es

  I OS sof t w are, b rid ging and sw it ch in g t echn ologies, r out in g pr ot ocols, an d n et wor k m anagem ent .

  — Prov ides int r odu ct ory in for m at ion ab out t he basic concept s and t echnolog ies of n et w or k ing, in clu ding LAN and WAN t echnologies, Cisco

  P ar t I : I nt r oduct ion t o I nt e rne t w ork i ng

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  — Discusses WAN t echnolog ies, includin g Fr am e Relay, HSSI , I SDN, PPP, SMD S, dialup , SDLC, X. 25, and VPNs.

Acknowledgments and Contributors

  Cisco Pr ess w ou ld lik e t o ex pr ess it s deep est gr at it ude t o t h e t alen t ed p eop le wh o cont r ibu t ed t o t he four t h edit ion of t his book . W it h out t heir help and ex per t ise, w e w ou ld n ot h ave b een able t o pu blish t h is ed it ion . Than k y ou t o all w ho helped w r it e and edit t he chap t er s in t h is new edit ion.

  Table of Content s •

  I n alp habet ical or der , t he cont rib ut or s ar e as f ollow s:

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Bru ce A le xa nd er

  is t he t echnical m ar ket ing m anag er for t h e Cisco Sy st em s Wir eless By Cisco Systems, Inc. Net w ork ing Business Un it . He join ed Cisco as a r esult of Cisco' s acquisit ion of Air onet Wireless Com m un icat ions, w h er e he w as t he d ir ect or of t ech nical supp ort . He has w or k ed in t he RF

  Pub lish er: Cisco Press

  t echnology ar ea f or m or e t han 27 y ears, an d h e has w or k ed w it h RF WAN t ech nology f or 17 y ear s. Alexan der has w or k ed ex t en siv ely wit h t h e RF eng in eer ing gr oup at Tex lon, in bot h Pub Dat e: Sep tem ber 1 1, 2 003 har dw ar e an d sof t w are, w her e he was t he senior inst r uct or f or nat ional ed ucat ion cent er s.

  I SBN: 1- 58 705 -1 19 -2

  Add it ion ally , h e has h eld an am at eu r r adio licen se sin ce 1 978 . He is a cof ound er of Amer it r on

  Pages: 11 28

  Am at eur Rad io Com pan y. Alex and er at t en ded Ak r on Un iv er sit y , w her e he m aj or ed in com pu t er pr ogr am m ing and business adm inist r at ion.

  Tony A ll en

  , CD ( Canadian Decorat ion ) , is a n et wor k consult in g eng ineer w or k ing for Cisco Sy st em s on t he Amer icas I n t er nat ion al Adv anced Ser v ices Team in Toron t o, Can ada. For t h e last The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of fou r y ear s, he has helped ser v ice p rov ider cust om ers plan, d esign, imp lem ent , an d operat e t heir essent ial an d cu t t ing- edg e t ech nologies. net w or k solu t ions. Befor e j oin ing Cisco, he spent 17 year s w it h t he Canadian Milit ar y, w or k ing in a v ar iet y of t elecom mu nicat ion s engineer in g and main t en ance posit ions. He cur r en t ly specializes in t he d esign, en gineering , and t est ing of VoI P, opt ical w ir eless t ech nologies, and br oadban d

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom net w or ks. He has a wif e, Debor ah, an d t wo childr en : Sar a, 5 , and Alex and er , 3 . His hob bies nov ice t o ex pert . include keeping abr east of t he lat est t echn olog y, gar dening , ph ysical fit n ess, and spendin g qu alit y t ime wit h his fam ily .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  Ma t t Ca rl in g

  is a net w or k consult ing engineer in t he Ad van ced Ser v ices Gr ou p at Cisco Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Sy st em s. Du ring t h e past t hr ee year s at Cisco, h e has w or k ed closely w it h man y ser v ice pr ovider cust om er s t o pr ov ide net w or kin g op t imizat ion solut ions, t echnolog y and ser v ices deploy m en t , Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . and im plement at ion of Cisco b est pr act ices net w or kin g t echn iq ues. He has m or e t han 1 2 y ears of exp er ience in n et wor k ing. He has a bachelor of engineerin g d eg ree in comp ut er engin eer ing and

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat a g r aduat e d iplom a in m anagem en t scien ces, bot h f rom t he Univ er sit y of Can berr a, Au st r alia.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  Bra dl ey D u nsm or e

  is a new p rod uct in st r uct or for t h e Adv anced Ser vices Gr oup at Cisco indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Sy st em s in Resear ch Tr iang le Park , N. C. He holds t he Cisco CCNP, CCD P, CCSI , an d CSS- 1 Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, cer t if icat ions, as w ell as an MCSE+ I nt er net f rom Microsoft . I n h is cur rent posit ion, h e desig ns and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or k t opolog ies f or new cour ses in h is gr oup and t r ains inst r uct or s t o t each t h e cou rses. net w or kin g p rof essionals, r egar dless of ex pert ise. Add it ion ally , h e desig ns n et w or k s t hat allow t he rem ot e and secu re dow nloading of t h ese cour ses. He specializes in SS7 I n t er conn ect solut ion s, WAN com mu nicat ions, and Cisco secu rit y Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e pr odu ct s. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Sa chin Gupt a

  is a pr odu ct m anager f or t h e Cisco Cat aly st 65 00. He holds a CCI E cer t if icat ion in t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Rou t ing and Sw it ch in g. Bef ore h is cur rent posit ion, h e w or ked for Cisco as a t echnical m ar ket ing Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy engineer in t he I nt er net Techn olog ies d ivision, w h er e he focused on Cisco I OS sof t w ar e syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich t echnologies. Bef or e t hat , Gup t a w as a cu st omer sup por t eng ineer at Cisco. He has a m ast er ' s pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease degr ee in elect rical eng in eer ing fr om St an for d Un iver sit y . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  W ay ne H i ck e y

  h as m or e t han 20 y ear s of t elecom m un icat ions and comp ut er dat a exp er ience, includin g SONET, SDH, D WDM, I P, ATM, Fram e, HFC, v oice, video, an d SSEM. He is a pr odu ct m anager f or t h e Opt ical Technical Business Unit at Cisco Sy st em s. Pr ev iously, he spent 19 y ear s w or king f or Aliant Telecom ( NBTel) , t he t h ir d - lar g est t elecomm u nicat ion s pr ov id er in Canada, Mod e Disp er sion ( PMD) and long- h aul t r an sm ission syst em s. He has ap plied f or sev eral pat ent s on pr im ary an d secondar y p roj ect s for h yb rid fib er coax ial ( HFC) .

  Qi an g H u ang

  , CCI E No. 493 7, is a cu st omer sup por t eng in eer in t he Cisco VPN and Net w or k Secu rit y Gr oups. He h as ex t ensiv e kn ow ledg e in man y secur it y pr od uct s and t echnologies, and he h as ser v ed as t he t echnical lead f or h is gr oup for t he past sev er al year s. Huang has mu lt ip le CCI E cert if icat ion s, in clu ding I SP Dial, Rout ing and Sw it ching, and Secur it y . He h as a m ast er' s degr ee in elect rical an d com pu t er en gineer ing f rom Color ado St at e Un iv er sit y .

  Table of Content s • I ndex • V e nk at Ka nk i pa t i h as been a soft w ar e dev elop ment m anager at Cisco Sy st em s f or six year s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  His exp er t ise spans a w ide r ang e of t ech nologies, in clu ding SNA pr ot ocols and secu rit y and By Cisco Systems, Inc. net w or k per for m ance. Bef or e joinin g Cisco, h e w ork ed f or Bay Net w or ks. Kan kipat i has a m ast er ' s degr ee in com pu t er science fr om t h e Un iver sit y of Massachu set t s, a mast er 's d eg r ee in com put er ap plicat ion s fr om t h e Un iver sit y of Madr as, and a b ach elor of scien ce degr ee fr om t h e

  Pub lish er: Cisco Press Univer sit y of Bomb ay, I n dia.

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Ma r ce lo N obr eg a

  , CCI E No. 806 9, is a senior n et wor k consult in g eng ineer at Cisco Sy st em s in

  Pages: 11 28

  t he Adv anced Serv ices Gr oup, wh ich supp or t s Am er icas I nt ern at ional Th eat er . He h as w ork ed w it h desig n d ep loy m ent , ad min ist r at ion, and t r oubleshoot ing of larg e ser v ice pr ovider n et w or k s since 199 4. He h as been w it h Cisco Sy st em s since 20 00. His focus h as been on cor e I P and r out ing pr ot ocols, net w or k m anagem en t , I P Telephon y, and, m ost recen t ly, I P call cent er s. Nobr ega h as a b achelor of science degr ee in elect r onic eng ineer ing and a mast er 's d eg ree in com put er science f r om Pont if icia Univ ersidad e Cat olica Univer sit y in Rio de Janeir o, Br azil. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Tom N ose ll a

  , CCI E No. 139 5, is senior m anager of t echnical m ar k et in g in t he St orag e Tech nology Grou p at Cisco Sy st em s. He and h is t eam cr eat e, v alid at e, and pr om ot e Cisco st or age net w or k in g d esign s and solut ions f or Cisco's ent er pr ise and ser v ice p rov ider cust om ers. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Befor e j oin ing Cisco, h e w as dir ect or of en gineering at Bell Canad a in Resid en t ial and nov ice t o ex pert . Com m ercial I nt er net Ser v ices, w here he led a t eam of sen ior en gineers. He h as a b ach elor of

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP engineer in g and man agem en t d eg ree f rom McMast er Univ ersit y in Ont ario, Canada. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  I v an P ep el nj a k

  , CCI E No. 135 4, has mor e t han t en y ears of ex per ience in designing , inst allin g, t r oub leshoot ing , and oper at ing lar ge ser v ice pr ovider an d en t er pr ise WAN an d LAN n et w or k s. He Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . is chief t echn ologies adv isor at NI L Dat a Comm u nicat ion s. He is t he ar chit ect of NI L' s Serv ice Pr ovid er Acad em y pr og ram , h e is one of t h e ar ch it ect s of t he Serv ice Pr ovider cur r icu lum at

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Cisco Sy st em s, and he is t he lead developer of sev eral ser v ice p rov ider cour ses t hat cov er MPLS, enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing BGP, an d I P QoS. Pepelnj ak is one of t h e Cisco r out ing aut hor it ies in Eu rop e. He w rot e t he Cisco t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Pr ess b ook EI GRP Net w ork D esign Solut ions and cow r ot e t he Cisco Pr ess b ook MPLS and VPN indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Ar ch it ect u res. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all

  D a nny Rod ri gue z

  is a net w or k secur it y eng in eer in t he Secur it y Con su lt ing Ser v ices net w or kin g p rof essionals, r egar dless of ex pert ise. or ganizat ion at Cisco Syst em s, w here h e per for m s secur it y p ost u re assessm ent s an d secur it y design rev iew s f or For t une 5 00 comp anies. He is also r espon sible f or t h e t r ain ing and Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e dev elop ment of t he ot her secur it y engin eer s in his gr oup . Du ring h is t en ur e w it h Cisco, h e has har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on been an edu cat ion specialist in t he Secur it y Tr aining depar t m ent in t h e Cisco I nt er net Lear ning a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions and Solut ion s Gr oup ( I LSG) . He aut hor ed t he Cisco I nt ru sion Det ect ion cour ses and con t r ib ut ed t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . t o lab ex er cises f or Cisco' s cor e secur it y cour ses. He also h as t aug ht cou rses on secur it y t o Cisco Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy engineer s, Cisco lear ning an d Chann el Part n er s, an d end user s. Rodr iguez w as also a k ey syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich cont r ibut or t o t h e CCSP cer t if icat ion pr ogr am . He h old s cer t ificat ions as a CCDA an d a CSS- 1 . pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient

  Sa e ed Sa rd ar

  h as w or ked as a d ev elopm en t eng ineer in t h e Hig h- Speed Swit chin g Grou p at decisions for t h eir net w ork s. Cisco Sy st em s f or m ore t han t w o y ears. He has w or ked ext ensiv ely w it h t est in g and resolving cont r ol an d d at a p lan e issu es f or Cisco I OS on t he Cisco Cat aly st 6 000 ser ies r elat ing t o I Pv4 ,

  I Pv6 , MPLS, QoS, an d m u lt icast r out in g and har dw ar e for w ar ding on a v ar iet y of LAN an d WAN m odules. m or e t han six year s of exp er ience in t he net w or kin g f ield . Since join in g Cisco in 20 00, he h as cont inu ed t o focus on secu rit y t echn ologies and pr oduct s. He cur r ent ly pr ov ides secur it y post u re assessment s and secur it y consult ing t o Cisco cu st omer s. He has t rain ed ot her Cisco eng ineer s in t he area of secur it y and w as t he t echn ical sp eak er at Cisco' s Net wor k ers Conv en t ion.

  Al an Trou p

  is a t echnical w r it er for t h e Cisco MDS 900 0 fam ily of st or ag e sw it ches. He w as pr eviou sly a t ech nical pub licat ions man ager in one of Cisco's op t ical sw it ch div isions. He h as a bachelor of ar t s degr ee in Eng lish fr om San Jose St at e Univ ersit y .

  • Table of Content s
  • I ndex

  Sr ini v as V e ge sna

  , CCI E No. 139 9, is m anag er of sof t w are developm ent in Cor e I P Eng in eer ing

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  at Cisco Syst em s. Bef ore his cur r en t posit ion, he w as a con su lt ing en gineer and m anager of By Cisco Systems, Inc. Cisco's Ser vice Pr ov id er Consult ing Ser vices. His ex per t ise is in gener al I P n et wor k ing, wit h a special focus on I P an d I P QoS. I n his m or e t han eight y ear s at Cisco, Veg esna has w or k ed w it h a lar ge num ber of serv ice pr ov id er and en t erp rise cust om er s, h elpin g t h em desig n, im plement ,

  Pub lish er: Cisco Press

  and t r oub leshoot larg e- scale I P net w or k s. He has a mast er of science d eg ree f r om Ar izon a St at e

  Pub Dat e: Sep tem ber 1 1, 2 003 Univer sit y and an MBA f rom Sant a Clar a Univer sit y.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Third Edition Contributors

  Con t rib ut or s t o t he Th ir d Ed it ion ( in alphab et ical or der ) ar e Marc Bresnik er , Ger r y Bur gess, Dav e Bust er , Kev in Ham ilt on , Br ian Ju nnila, An dr ew Kessler , William Lan e, Kev in Mahler, Er ick Mar , Kevin Mousseau, Jim O'Shea, W illiam Par k hur st , Ed ie Quir oz, Neil Reid, Fr ank Riv est , Mar k

  Table of Content s • Spor t ack , John St r assn er , an d Nat alie Tim m s.

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

First Edition Contributors

  Pr incip al aut hor s of t he f irst ed it ion of t h is book w er e Merilee Ford , H. Kim Lew , St ev e Span ier , and Tim St ev en son .

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Part I: Introduction to Internetworking Ch apt er 1 I n t er net w or k in g Basics Ch apt er 2 I n t rod uct ion t o LAN Pr ot ocols

  • Table of Content s

  Ch apt er 3 I ndex I n t rod uct ion t o WAN Techn ologies • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Ch apt er 4 I n t rod uct ion t o Cisco I OS Soft w ar e By Cisco Systems, Inc. Ch apt er 5 Br idg ing and Sw it ch in g Basics

  Pub lish er: Cisco Press Ch apt er 6 Rout ing Basics Pub Dat e: Sep tem ber 1 1, 2 003 Ch apt er 7 Net w or k Man agement Basics

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 1. Internetworking Basics Obj e ct i ve s

  • Table of Content s Lear n wh at m ak es up an int ern et wor k .
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Lear n t he b asics of t he OSI m odel.

  By Cisco Systems, Inc.

  Lear n t he d if fer en ces b et w een con nect ion - orient ed and connect ionless ser vices.

  Pub lish er: Cisco Press Lear n about t he d iff er ent t yp es of addr esses used in an int er net w ork .

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Lear n about flow con t rol and err or - check ing basics. Pages: 11 28

  This chap t er w ork s w it h t he next six ch apt ers t o act as a f ound at ion f or t h e t ech nology discussion s t hat follow . I n t his chapt er , som e fu ndam ent al con cept s and t erm s u sed in t he evolv ing langu age of int er net w or king ar e add r essed . I n t he sam e w ay t hat t his b ook pr ov id es a fou ndat ion f or un derst and ing m odern net w or k in g, t h is chapt er sum m ar izes som e com mon t hem es pr esent ed t hr oug hout t he rem ainder of t h is book . Topics include flow cont r ol, er ror The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of check ing , and m ult iplexin g, b ut t his chapt er f ocuses m ainly on m app in g t he Op en Sy st em essent ial an d cu t t ing- edg e t ech nologies. I nt er con nect ion ( OSI ) m odel t o n et wor k ing/ in t er n et w or k in g fun ct ion s, and also sum m arizing t h e gener al nat ur e of addr essing schemes w it hin t h e con t ext of t he OSI m odel. The OSI mod el r ep r esent s t h e buildin g b lock s f or int er net w ork s. Under st anding t h e concep t ual m odel h elp s you

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom un derst an d t h e comp lex p ieces t hat m ake up an in t er n et w or k . nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is an Internetwork?

  An int ern et wor k is a collect ion of in div id ual n et w or k s, con nect ed by in t erm ediat e n et w or k ing dev ices, t hat fu nct ions as a single lar ge n et w or k . I nt er net w ork ing r ef ers t o t h e indu st r y , pr odu ct s, and pr ocedu r es t hat m eet t h e challen ge of creat ing an d ad min ist er ing int ern et wor k s.

  • Table of Content s

  

Figur e 1- 1 illust r at es some diff er ent kin ds of net w or k t echnologies t hat can be int er connect ed by

  • I ndex r out er s and ot her n et w or k ing devices t o cr eat e an int ern et wor k .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 1 - 1 . Di ff e r en t N et w or k Tech nol ogie s Ca n Be Con ne ct ed t o Cr e at e

Pub lish er: Cisco Press

a n I n t e r ne t w or k

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

History of Internetworking

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. The f ir st net w or ks wer e t im e- sh aring n et w or k s t hat used m ainf r ames an d at t ach ed t er m in als. Such en vir onm ent s wer e im plem ent ed by b ot h I BM's Sy st em s Net w or k Ar ch it ect ur e ( SNA) and Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Digit al' s net w or k ar ch it ect ur e. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Local- area net w ork s ( LANs) a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions ev olved ar ound t he PC r ev olu t ion. LANs en abled m ult ip le user s in a t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . r elat iv ely sm all g eog rap hical ar ea t o ex ch ange files and m essages, as w ell as access shar ed Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy r esour ces such as file ser v er s an d pr in t ers. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

  Wide- area net w ork s ( WANs)

  in t er conn ect LANs w it h geogr aphically dispersed user s t o creat e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease connect ivit y . Som e of t h e t ech nologies used f or connect ing LANs in clud e T1, T3 , ATM, I SDN, pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient ADSL, Fr am e Relay , r adio link s, and ot h er s. New m et hods of conn ect ing d isper sed LANs are decisions for t h eir net w ork s. app ear ing ever y day .

  Today , h ig h- speed LANs and sw it ch ed int er net w ork s ar e b ecom ing w id ely u sed , larg ely b ecause

  I nt er net w ork ing evolv ed as a solut ion t o t h r ee k ey pr oblem s: isolat ed LANs, du plicat ion of r esour ces, and a lack of net w or k m anagem en t . I solat ed LANs mad e elect r onic comm u nicat ion bet w een dif fer en t of fices or depar t m ent s im possible. Dup licat ion of resour ces m eant t hat t he sam e har dw ar e and soft w ar e had t o be sup plied t o each off ice or depar t m ent , as d id separ at e supp ort st aff . This lack of net w or k m anag em ent meant t hat no cen t ralized met h od of m anag ing and t r oub leshoot ing n et w or k s exist ed.

  • Table of Content s

  I ndex

Internetworking Challenges

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion I m plem ent ing a fu nct ional int er net w or k is no sim ple t ask . Man y challen ges m ust b e faced, By Cisco Systems, Inc.

  esp ecially in t he ar eas of con nect iv it y , r eliabilit y , net w or k m anagem ent , an d f lex ibilit y . Each ar ea is k ey in est ablish ing an ef ficient and eff ect iv e int er net w or k.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  The ch alleng e w hen conn ect ing v ar iou s syst em s is t o su ppor t com m un icat ion am ong dispar at e

  I SBN: 1- 58 705 -1 19 -2

  t echnologies. Diff erent sit es, f or exam ple, m ay u se d iff er ent t yp es of media operat in g at v ar ying

  Pages: 11 28 speed s, or m ay even inclu de d if fer ent t yp es of sy st em s t h at n eed t o com m unicat e.

  Becau se com pan ies r ely heav ily on d at a com mu nicat ion, int er net w or ks mu st pr ov ide a cer t ain level of r eliab ilit y . Th is is an u npr edict able w or ld, so m an y larg e int ern et wor k s include r ed und ancy t o allow for com m unicat ion ev en w h en pr oblem s occu r . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Fur t her mor e, net w or k m anag em ent mu st pr ov ide cent r alized supp ort and t r oub leshoot ing essent ial an d cu t t ing- edg e t ech nologies. capabilit ies in an int er net w or k. Conf igur at ion, secur it y, perf or man ce, an d ot her issues m ust be adequ at ely ad dr essed f or t h e int ern et wor k t o fu nct ion sm oot h ly . Secur it y w it hin an in t er n et w or k is essent ial. Man y people t h ink of net w or k secur it y f rom t he p er spect iv e of p rot ect ing t he pr iv at e

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom net w or k fr om ou t sid e at t ack s. How ev er , it is ju st as im por t ant t o pr ot ect t he n et wor k f r om nov ice t o ex pert . int er nal at t ack s, esp ecially because m ost secur it y br eaches come fr om inside. Net w ork s m ust also be secur ed so t hat t he int er nal n et wor k cann ot b e used as a t ool t o at t ack ot h er ex t ern al

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP sit es. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Ear ly in t he y ear 20 00, m an y m ajor w eb sit es w er e t he v ict im s of d ist r ibu t ed d en ial of ser v ice ( DD OS) at t ack s. These at t acks w er e possible because a g r eat num b er of p r iv at e n et w or k s Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . cur r en t ly con nect ed w it h t he I nt er net wer e not pr oper ly secur ed. Th ese pr iv at e net w or ks w er e

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat used as t ools for t he at t ack ers.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Becau se not hing in t his w or ld is st agnan t , int er net w ork s m ust be f lex ible enoug h t o chang e w it h indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . new d em and s. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Open System Interconnection Reference Model

  The Op en Sy st em I nt er connect ion ( OSI ) refer ence m odel d escr ibes how in for m at ion f r om a soft w ar e app licat ion in one com put er m ov es t hr ough a net w ork mediu m t o a soft w ar e app licat ion in an ot her com put er . The OSI r ef erence m odel is a concep t ual m od el com posed of

  • Table of Content s

  sev en lay er s, each sp ecify ing par t icular n et w or k f unct ions. Th e m odel w as dev elop ed by t he

  • I ndex

  I nt er nat ional Or ganizat ion for St andar dizat ion ( I SO) in 1 984 , and it is n ow considered t he

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  pr im ary archit ect ur al m odel f or int er comp ut er com mu nicat ions. The OSI m odel div ides t he t ask s By inv olved w it h m ov ing inf orm at ion bet w een net w or ked comp ut er s int o sev en sm aller , m or e Cisco Systems, Inc. m anageable t ask g r oups. A t ask or gr oup of t ask s is t hen assign ed t o each of t he sev en OSI lay er s. Each layer is r eason ably self - cont ained so t hat t he t ask s assigned t o each lay er can b e

  Pub lish er: Cisco Press

  im plem ent ed independ en t ly. This enables t he solut ion s off ered by on e layer t o be u pdat ed

  Pub Dat e: Sep tem ber 1 1, 2 003

  w it hout adv er sely aff ect in g t h e ot her lay ers. Th e follow ing list det ails t he seven layer s of t he

  I SBN: 1- 58 705 -1 19 -2

  Op en Sy st em I n t er connect ion ( OSI ) r efer en ce m od el:

  Pages: 11 28

  Lay er 7— Applicat ion Lay er 6— Presen t at ion

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Lay er 5— Session essent ial an d cu t t ing- edg e t ech nologies.

  Lay er 4— Tran sp ort Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Lay er 3— Net w or k nov ice t o ex pert .

  Lay er 2— Dat a link New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Lay er 1— Phy sical Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

NO TE

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing A h andy way t o r emem ber t h e sev en lay ers is t he sent ence " All people seem t o indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . need d at a p rocessing . " The beginnin g let t er of each w or d cor r esp onds t o a lay er . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  All— Applicat ion lay er Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  People— Presen t at ion lay er har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Seem — Session lay er t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  To— Tran sp ort lay er syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Need — Net w or k lay er pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient

  Dat a— Dat a link lay er decisions for t h eir net w ork s. Pr ocessin g— Phy sical lay er Figur e 1- 2 illust r at es t he sev en - layer OSI refer ence m odel.

  

Figu r e 1 - 2 . The O SI Ref e r en ce M ode l Con t ai ns Se ve n I n de pen de nt

La ye r s

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Characteristics of the OSI Layers

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  The sev en lay er s of t h e OSI r efer en ce m od el can be divid ed int o t w o cat egor ies: upp er lay er s and low er layer s.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The up per lay er s of t he OSI m od el deal w it h applicat ion issues and gener ally are im plem en t ed

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  only in soft w ar e. The h ighest lay er , t he app licat ion layer , is closest t o t he en d u ser . Bot h users enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing and app licat ion layer p rocesses int er act w it h soft w ar e app licat ions t hat con t ain a t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing com mu nicat ion s com ponent . The t er m up per layer is som et im es used t o r efer t o any lay er abov e indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . anot h er layer in t he OSI m odel.

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all The lower lay er s of t h e OSI m odel h andle d at a t r anspor t issues. The phy sical lay er and t he dat a net w or kin g p rof essionals, r egar dless of ex pert ise. link lay er are im plem en t ed in har dw ar e an d sof t w are. Th e lowest lay er, t he p hy sical lay er , is closest t o t he p hy sical n et wor k m edium ( t he n et w or k cabling , for ex am ple) and is r esp onsible for Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e act ually placing infor m at ion on t he m edium . har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Figur e 1- 3 illust r at es t he division bet w een t he u pper an d low er OSI lay ers.

  t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  

Figu r e 1 - 3 . Tw o Se t s of La ye r s M a ke U p t he O SI Lay er s

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Protocols

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The OSI m odel pr ov ides a concept u al fr am ewor k f or com mu nicat ion b et w een com pu t er s, b ut t he m odel it self is n ot a m et h od of com m unicat ion. Act u al comm u nicat ion is m ade possible b y using com mu nicat ion p rot ocols. I n t he cont ex t of d at a n et w or k in g, a pr ot ocol is a for m al set of r ules

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom and conv ent ions t h at g over ns h ow com put er s exchan ge inf or mat ion ov er a net w or k m edium . A nov ice t o ex pert . pr ot ocol im plem en t s t he f un ct ion s of one or m or e of t h e OSI lay er s.

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP A w ide var iet y of comm un icat ion pr ot ocols exist . Som e of t h ese p rot ocols includ e LAN p r ot ocols, WAN p r ot ocols, n et w or k pr ot ocols, and r out ing p rot ocols. LAN pr ot ocols op er at e at t h e phy sical Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age and dat a link lay er s of t h e OSI m odel an d define com m unicat ion over t h e v arious LAN m edia.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  WAN pr ot ocols op er at e at t h e lowest t hr ee lay ers of t he OSI mod el and defin e com m un icat ion

  ov er t he v ar iou s w ide- ar ea m ed ia. Rou t in g pr ot ocols ar e n et wor k lay er pr ot ocols t hat ar e

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  r espon sib le for ex ch angin g in for m at ion b et w een rou t er s so t hat t he r out er s can select t he p rop er enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing pat h f or net w or k t r aff ic. Finally , net w or k pr ot ocols ar e t he v ariou s upp er - lay er pr ot ocols t hat t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing exist in a given pr ot ocol suit e. Man y pr ot ocols r ely on ot her s f or oper at ion. For exam p le, m any indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . r out ing pr ot ocols use n et w or k p rot ocols t o ex chan ge inf orm at ion bet w een r out er s. This concept Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, of bu ild in g upon t he lay er s already in ex ist ence is t h e fou ndat ion of t he OSI m odel. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

OSI Model and Communication Between Systems

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on I nf orm at ion being t r ansfer red fr om a soft w ar e app licat ion in on e comp ut er sy st em t o a sof t w are a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions app licat ion in an ot her m ust pass t hr oug h t he OSI lay ers. For ex am ple, if a soft w ar e app licat ion t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy in Syst em A has inf orm at ion t o t ran smit t o a soft w ar e app licat ion in Sy st em B, t h e applicat ion syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr ogr am in Sy st em A w ill pass it s inf or mat ion t o t he ap plicat ion lay er ( Lay er 7) of Sy st em A. Th e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease app licat ion layer t h en passes t he in for m at ion t o t he pr esent at ion layer ( Layer 6 ) , w hich relay s t he dat a t o t h e session lay er ( Lay er 5) , an d so on d ow n t o t h e phy sical lay er ( Lay er 1) . At t h e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient ph ysical layer , t h e infor m at ion is placed on t he phy sical n et wor k m edium and is sent acr oss t he decisions for t h eir net w ork s. m ed ium t o Syst em B. The ph ysical layer of Sy st em B r emov es t he in for m at ion fr om t h e phy sical m ed ium , and t h en it s p hy sical lay er passes t h e infor m at ion up t o t he dat a link lay er ( Lay er 2) , w hich passes it t o t h e net w or k layer ( Layer 3 ) , and so on , unt il it r each es t he app licat ion layer

Interaction Between OSI Model Layers

  A g iven layer in t he OSI m odel gener ally com m un icat es w it h t hr ee ot her OSI lay er s: t he lay er dir ect ly ab ove it , t he lay er dir ect ly b elow it , and it s peer layer in ot her n et wor k ed com put er syst em s. The d at a link lay er in Sy st em A, f or ex am ple, com mu nicat es wit h t h e net w or k layer of Sy st em A, t he p hy sical lay er of Syst em A, an d t he dat a link lay er in Sy st em B. Figur e 1- 4

  Table of Content s • illust rat es t his exam ple. I ndex •

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 1 - 4 . OSI M ode l Lay er s Com m un icat e w i t h O t h er Lay e r s

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  OSI Layer Services Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  On e OSI lay er com m un icat es w it h anot h er lay er t o m ak e use of t h e ser v ices pr ov ided by t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing second lay er . Th e ser v ices p rov ided by adj acen t lay er s h elp a given OSI lay er com m un icat e wit h t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing it s peer lay er in ot h er com pu t er sy st ems. Th r ee b asic element s ar e inv olv ed in lay er ser vices: indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . t he ser vice user , t he ser vice pr ov ider, and t he ser vice access poin t ( SAP) . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all I n t his cont ex t , t he ser v ice u ser is t he OSI lay er t hat r eq uest s ser v ices f rom an ad jacent OSI net w or kin g p rof essionals, r egar dless of ex pert ise. lay er . Th e ser v ice p rov ider is t he OSI lay er t hat pr ov ides ser v ices t o ser v ice u ser s. OSI lay er s can pr ovide ser vices t o m u lt ip le ser v ice u ser s. The SAP is a concept ual locat ion at wh ich one OSI Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e lay er can r eq uest t he ser vices of anot h er OSI lay er . har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Figur e 1- 5 a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions illust r at es how t hese t hr ee elem en t s int er act at t he n et w or k and d at a link lay ers. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  

Figu r e 1 - 5 . Se r vi ce User s, Pr ovi de r s, a nd SAPs I nt e r a ct at t h e Ne t w or k

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient

  

a nd Da t a Li nk Lay e r s decisions for t h eir net w ork s. Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

OSI Model Layers and Information Exchange

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The sev en OSI lay ers use v arious for m s of cont r ol inf orm at ion t o com m un icat e w it h t h eir p eer nov ice t o ex pert . lay er s in ot her com put er sy st em s. This cont r ol in for m at ion con sist s of specif ic r eq uest s and inst r uct ions t h at ar e ex ch anged bet w een peer OSI lay er s.

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Con t rol infor m at ion t y pically t ak es one of t wo for m s: h ead er s and t r ailers. Headers ar e

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age pr epended t o d at a t hat h as been p assed dow n fr om u pper lay er s. Tr ailer s ar e ap pended t o d at a t hat has been passed d own f r om upp er layer s. An OSI layer is n ot r equir ed t o at t ach a h ead er or Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . a t railer t o dat a f r om up per layer s.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Headers, t r ailers, an d d at a ar e r elat ive concept s, d ep en ding on t he lay er t hat analy zes t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing inf orm at ion un it . At t he net w or k layer , f or exam ple, an inf orm at ion un it consist s of a Lay er 3 t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing header an d d at a. At t he d at a link lay er, how ev er , all t he in for m at ion passed dow n by t h e indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . net w or k layer ( t he Lay er 3 header and t h e dat a) is t r eat ed as dat a. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all I n ot her w or ds, t he d at a p ort ion of an inf orm at ion un it at a giv en OSI layer p ot en t ially can net w or kin g p rof essionals, r egar dless of ex pert ise. cont ain header s, t railer s, and dat a fr om all t h e high er lay er s. This is k now n as encapsulat ion .

  Figur e 1- 6 sh ows how t h e header and d at a f rom one lay er are en cap su lat ed int o t he h ead er of

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e t he next low est lay er . har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Figu r e 1 - 6 . He ade r s a nd Da t a Can Be En ca psu la t e d D ur i ng I nf or m at ion pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  

Excha ng e

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Information Exchange Process

  The in for m at ion ex change pr ocess occu r s bet w een peer OSI lay er s. Each lay er in t h e sou r ce The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of syst em ad ds cont r ol inf or mat ion t o dat a, and each layer in t he dest in at ion sy st em analyzes an d essent ial an d cu t t ing- edg e t ech nologies. r em ov es t he cont rol in for m at ion fr om t h at dat a.

  I f Syst em A has dat a f rom a soft w ar e app licat ion t o send t o Syst em B, t h e dat a is passed t o t he Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom app licat ion layer . The applicat ion lay er in Sy st em A t h en com m unicat es any cont r ol in for m at ion nov ice t o ex pert . r eq uir ed by t he ap plicat ion lay er in Sy st em B by p r ep en ding a h ead er t o t h e dat a. Th e r esult in g inf orm at ion un it ( a header and t he dat a) is passed t o t he pr esen t at ion lay er, w hich p repend s it s

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP ow n header cont aining cont r ol in for m at ion in t en ded f or t h e pr esent at ion lay er in Sy st em B. The inf orm at ion un it gr ow s in size as each lay er p r ep en ds it s ow n header ( an d, in som e cases, a

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age t r ailer ) t hat con t ains cont r ol in for m at ion t o be u sed by it s peer lay er in Syst em B. At t he p hy sical lay er , t h e ent ir e infor m at ion unit is placed ont o t h e net w ork mediu m.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . The p hy sical lay er in Sy st em B r eceiv es t he inf or mat ion un it an d p asses it t o t he dat a lin k layer .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  The d at a link lay er in Syst em B t hen r eads t he cont r ol inf or mat ion cont ain ed in t he h ead er enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing pr epended by t h e dat a link lay er in Sy st em A. The h ead er is t hen r em oved, and t he r em ain der of t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t he in for m at ion unit is passed t o t he net w or k lay er . Each lay er perf or ms t he sam e act ions: The indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . lay er r eads t he header f rom it s peer layer , st r ips it of f, and passes t he r emainin g in for m at ion Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, un it t o t he n ex t highest lay er. Aft er t h e applicat ion lay er per for m s t hese act ions, t he dat a is and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all passed t o t he r ecip ien t soft war e ap plicat ion in Syst em B, in exact ly t h e for m in w hich it w as net w or kin g p rof essionals, r egar dless of ex pert ise. t r ansm it t ed b y t he ap plicat ion in Syst em A. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

OSI Model Physical Layer t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The p hy sical lay er defines t h e elect r ical, m echanical, pr oced ur al, and f unct ional sp ecificat ions f or syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich act ivat in g, m aint ainin g, an d d eact iv at ing t he p hy sical link b et ween com m un icat ing n et w or k pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease syst em s. Phy sical lay er sp ecif icat ions define char act erist ics such as volt ag e lev els, t im ing of pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient v olt age chang es, p hy sical d at a r at es, m axim um t ran smission d ist an ces, and ph ysical connect or s. decisions for t h eir net w ork s. Phy sical lay er im plement at ion s can b e cat eg or ized as eit her LAN or WAN specificat ions. Figur e 1- 7 illust r at es some com m on LAN an d WAN ph ysical layer im plem en t at ions.

  

Specif ica t i ons

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

OSI Model Data Link Layer

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The d at a link lay er pr ov ides r eliable t r ansit of dat a acr oss a p hy sical n et w or k link . Dif fer en t d at a

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP link lay er sp ecificat ions d ef ine d if fer en t n et w or k an d p rot ocol ch aract er ist ics, including p hy sical add ressin g, n et w or k t op olog y, er r or n ot if icat ion , seq uencing of fr am es, an d flow cont r ol. Ph ysical

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age add ressin g ( as opposed t o n et w or k add r essin g) defines h ow dev ices ar e add ressed at t he dat a link lay er . Net w or k t opolog y con sist s of t h e dat a lin k layer specificat ions t h at of t en d ef ine how Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . dev ices ar e t o be ph ysically con nect ed, su ch as in a bus or a r ing t opology . Er ror not ificat ion alert s upp er - lay er pr ot ocols t hat a t r ansm ission er r or has occur r ed, and t h e seq uencin g of dat a

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  fr am es r eor der s f ram es t hat ar e t r ansm it t ed ou t of sequence. Fin ally , f low cont r ol m oder at es t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t r ansm ission of dat a so t hat t he r eceiv ing device is not ov er w helm ed w it h m ore t raf fic t han it can t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing han dle at one t im e. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, The I n st it u t e of Elect rical an d Elect r onics En gineer s ( I EEE) has sub divid ed t he dat a lin k layer int o and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t w o su blayer s: Log ical Link Cont r ol ( LLC) and Media Access Cont r ol ( MAC) . Figur e 1- 8 illust r at es net w or kin g p rof essionals, r egar dless of ex pert ise. t he I EEE sublay er s of t h e dat a lin k layer .

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

Figu r e 1 - 8 . The Da t a Lin k La ye r Cont ai ns Tw o Subl ay er s t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The Logical Lin k Con t rol ( LLC) su blayer of t h e dat a lin k layer m anag es com m un icat ions bet w een dev ices ov er a single link of a net w or k. LLC is d ef ined in t he I EEE 802 . 2 specificat ion an d supp ort s bot h connect ionless an d con nect ion - orient ed ser v ices u sed by h ig her- lay er pr ot ocols.

  I EEE 8 02. 2 defines a num b er of f ield s in d at a link lay er fr am es t hat enable m ult iple h igher - layer pr ot ocols t o sh are a single p hy sical dat a link . The Media Access Con t r ol ( MAC) su blayer of t h e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of dat a link lay er man ages pr ot ocol access t o t he p hy sical n et w or k m edium . Th e I EEE MAC essent ial an d cu t t ing- edg e t ech nologies. specif icat ion def in es MAC addr esses, w hich enab le mu lt iple dev ices t o uniqu ely id en t if y one anot h er at t h e dat a lin k layer .

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

OSI Model Network Layer

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  The n et wor k lay er defines t h e net w or k add ress, w hich d if fer s fr om t he MAC add ress. Som e net w or k layer im plem en t at ions, such as t he I nt er net Prot ocol ( I P) , define net w ork ad dr esses in a Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . w ay t hat r out e select ion can b e det erm ined syst em at ically by com par ing t h e sou r ce n et wor k add ress w it h t he d est inat ion net w or k add ress and app lying t h e su bnet m ask . Because t his lay er

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  defin es t he logical net w or k lay out , r out er s can use t his lay er t o d et er m ine how t o f or war d enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing pack et s. Because of t his, m uch of t he design an d conf igur at ion w ork for in t er net w or k s happ en s t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing at Lay er 3, t h e net w or k layer . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all

OSI Model Transport Layer net w or kin g p rof essionals, r egar dless of ex pert ise

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e The t ran sp ort lay er accept s d at a f rom t he session layer an d segm ent s t h e dat a for t ran sp ort har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on across t he net w or k. Generally , t he t r anspor t lay er is respon sible f or m ak in g su re t hat t he dat a is a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions deliver ed er ror - f r ee an d in t h e pr oper seq uence. Flow con t r ol gener ally occur s at t he t ran sp ort t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . lay er .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Flow cont r ol m anag es d at a t r an sm ission bet w een dev ices so t hat t he t r ansm it t ing dev ice d oes syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich not sen d m or e dat a t h an t h e r eceiving d ev ice can pr ocess. Mult iplexing enables d at a f rom pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease sev er al applicat ions t o be t ran sm it t ed ont o a single p hy sical link . Vir t ual cir cuit s ar e est ab lish ed , pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient m aint ained, and t er m inat ed by t h e t r anspor t lay er. Er r or ch eck ing inv olves cr eat in g v ar ious decisions for t h eir net w ork s. m ech anism s f or det ect ing t r ansmission er r ors, w h ile er r or r ecov er y inv olv es act ing , such as r eq uest in g t hat dat a be r et ran sm it t ed, t o r esolv e any er r ors t hat occur .

  OSI Model Session Layer The session layer est ablishes, man ages, and t erm inat es com m unicat ion session s.

  Com m un icat ion sessions consist of ser v ice r equ est s an d ser vice r espon ses t h at occur b et ween app licat ions locat ed in d if fer ent n et wor k d ev ices. Th ese r equest s and r esp onses are coor dinat ed by p r ot ocols im plem en t ed at t he session lay er . Som e ex amp les of session- lay er imp lem ent at ion s include Zon e I nf orm at ion Pr ot ocol ( ZI P) , t he Ap pleTalk pr ot ocol t hat coord inat es t he n am e

  • Table of Content s

  bind ing pr ocess; an d Session Con t r ol Pr ot ocol ( SCP) , t he DECnet Phase I V session lay er

  I ndex • pr ot ocol.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. OSI Model Presentation Layer

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  The p r esent at ion layer p rov ides a var iet y of cod ing and conv er sion f un ct ion s t hat ar e applied t o

  I SBN: 1- 58 705 -1 19 -2

  app licat ion layer d at a. These fu nct ions ensur e t h at inf or mat ion sent f r om t he applicat ion lay er of

  Pages: 11 28

  one sy st em w ould be r ead able by t he app licat ion layer of an ot her syst em . Som e exam ples of pr esent at ion lay er coding and conv er sion schem es in clu de com mon d at a r epr esent at ion for m at s, conv er sion of ch aract er r ep r esent at ion for m at s, com mon dat a com pr ession schem es, an d com mon dat a encr yp t ion schem es.

  Com m on dat a repr esen t at ion f or mat s, or t he u se of st an dar d im ag e, sou nd, an d video for m at s, The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of enable t h e int er ch ange of ap plicat ion d at a bet w een d if fer ent t yp es of com pu t er sy st ems. essent ial an d cu t t ing- edg e t ech nologies.

  Con ver sion schemes ar e used t o ex ch ange in for m at ion w it h syst em s by u sin g d iff er ent t ex t and dat a r ep resent at ions, such as EBCDI C an d ASCI I . St andar d dat a com pr ession sch em es enable dat a t hat is com pr essed at t he sour ce dev ice t o be pr operly d ecom pr essed at t h e dest in at ion. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom St and ard d at a encr yp t ion schem es en able dat a en cry pt ed at t he sour ce device t o be p rop er ly nov ice t o ex pert . decipher ed at t he d est inat ion .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Pr esent at ion lay er im plem en t at ions ar e n ot t y pically associat ed w it h a p ar t icu lar pr ot ocol st ack . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Som e w ell- k now n st andar ds for v ideo in clud e Quick Time and Mot ion Pict u re Ex pert s Gr oup ( MPEG) . Qu ick Tim e is an Apple Comp ut er specif icat ion f or vid eo and aud io, and MPEG is a Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . st andar d f or vid eo com p ression and coding .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Am ong t he w ell- kn ow n g r aphic im age f or mat s are Gr aphics I nt er ch ange For m at ( GI F) , Join t enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Phot og r aphic Exp er t s Grou p ( JPEG) , an d Tagged I m ag e File For m at ( TI FF) . GI F is a st an dar d f or t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing com pr essing and coding gr aph ic im ag es. JPEG is an ot her com pr ession an d cod in g st an dar d for indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . gr aph ic imag es, an d TI FF is a st an dar d cod ing for m at f or gr aph ic imag es. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

OSI Model Application Layer

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e The ap plicat ion lay er is t he OSI layer closest t o t h e en d user , w hich m ean s t hat bot h t h e OSI har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on app licat ion layer an d t h e user int er act dir ect ly w it h t he sof t w ar e applicat ion. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . This lay er int er act s wit h soft war e ap plicat ion s t hat im plem ent a com m unicat ing comp onent . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Such applicat ion pr ogr am s fall ou t sid e t he scope of t h e OSI m od el. Ap plicat ion lay er fun ct ion s syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich t y pically in clu de ident if ying com m unicat ion par t ner s, det er m ining r esour ce av ailab ilit y , an d pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease syn ch r onizing com m un icat ion. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  When ident if ying com mu nicat ion p ar t ners, t he app licat ion layer d et er m in es t he ident it y and av ailab ilit y of com m unicat ion par t ner s for an ap plicat ion w it h dat a t o t r an sm it . Wh en det er min in g r esour ce availabilit y , t he ap plicat ion lay er m ust decide w het h er suf ficient n et wor k lay er . Som e exam ples of app licat ion layer im plem en t at ions includ e Teln et , File Tr ansfer Pr ot ocol ( FTP) , and Sim ple Mail Tr ansf er Prot ocol ( SMTP) .

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Information Formats

  The d at a an d con t rol infor m at ion t hat is t r ansm it t ed t h rou gh int ern et wor k s t ak es a v ar iet y of for m s. The t er m s used t o r efer t o t hese in for m at ion for m at s ar e not used consist en t ly in t he int er net w ork ing ind ust r y but somet im es ar e used int er chang eab ly . Comm on inf orm at ion f orm at s

  • Table of Content s include fr am es, p ack et s, dat ag ram s, seg m en t s, m essages, cells, and dat a unit s.
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  A f r ame is an in for m at ion u nit wh ose sou rce an d d est inat ion ar e dat a link lay er en t it ies. A fr am e is com posed of t he dat a lin k layer header ( an d possib ly a t r ailer ) and upp er - lay er dat a. Th e

  By Cisco Systems, Inc.

  header an d t r ailer cont ain con t r ol inf orm at ion int ended for t he d at a link lay er en t it y in t he dest inat ion sy st em. Dat a fr om up per - lay er ent it ies is encapsulat ed in t he dat a lin k layer header

  Pub lish er: Cisco Press and t r ailer . Figur e 1- 9 illust r at es t he basic com pon en t s of a dat a link lay er f ram e.

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 1 - 9 . Da t a f r om Upp er - La ye r En t it ie s M ak e s Up t he D at a Lin k La ye r Fr am e

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  A pack et is an inf or m at ion u nit w h ose sour ce and d est inat ion ar e net w or k layer ent it ies. A p ack et is com posed of t he net w ork lay er header ( an d p ossibly a t r ailer ) an d upper - lay er d at a. The Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . header an d t r ailer cont ain con t r ol inf orm at ion int ended for t he n et w or k lay er en t it y in t he dest inat ion sy st em. Dat a fr om up per - lay er ent it ies is encapsulat ed in t he net w ork lay er header

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat and t r ailer . Figur e 1- 1 0 illust r at es t he basic com pon en t s of a net w ork lay er pack et .

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

Figu r e 1 - 1 0 . Th r ee Ba si c Com pon en t s M a k e Up a N et w or k Lay er Packe t

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The t er m dat agr am u sually ref er s t o an in for m at ion unit w hose sou r ce an d dest in at ion ar e net w or k layer ent it ies t h at u se conn ect ionless net w or k ser v ice. The t er m segm ent u sually ref er s t o an in for m at ion unit w hose sou r ce an d dest in at ion ar e

  A m essage is an inf or m at ion u nit w h ose sour ce and d est inat ion ent it ies ex ist ab ove t he net w or k lay er ( oft en at t h e applicat ion lay er ) . A cell is an inf or m at ion u nit of a fix ed size w hose sour ce and dest inat ion are dat a lin k layer ent it ies. Cells ar e u sed in sw it ched en vir onm ent s, such as Asyn ch ron ous Tr ansfer Mode ( ATM) and Sw it ched Mult im eg abit D at a Ser vice ( SMDS) net w or ks. A cell is com posed of t he header an d pay load. Th e header cont ains con t r ol inf orm at ion int ended for t he d est inat ion dat a link lay er ent it y an d is t yp ically 5 by t es long. Th e pay load con t ains up per - lay er dat a t hat is encapsulat ed

  • Table of Content s in t he cell header and is t y pically 48 by t es long.

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  The leng t h of t he header an d t he pay load fields alw ays are t he sam e for each cell. Figur e 1- 1 1 By Cisco Systems, Inc. depict s t h e comp onent s of a t y pical cell.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 1 - 1 1 . Tw o Com p on e nt s M ak e Up a Typi ca l Ce ll

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  

Dat a unit is a gener ic t erm t hat ref er s t o a v ar iet y of in for m at ion u nit s. Som e com mon dat a un it s

  I n t ern et w or k in g Tech nologies Hand book ar e ser v ice d at a u nit s ( SDUs) , pr ot ocol d at a u nit s, and br idg e pr ot ocol dat a un it s ( BPDUs) . SDUs , Four t h Ed it ion , is a com pr ehensive refer ence t hat enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing ar e inf orm at ion un it s fr om u pper - layer pr ot ocols t h at def in e a ser vice r eq uest t o a low er- lay er t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing pr ot ocol. PDU is OSI t erm inolog y for a pack et . BPDUs are used by t he span ning- t ree algor it hm indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . as h ello m essag es. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ISO Hierarchy of Networks

  Lar ge net w ork s t y pically ar e org anized as hier ar chies. A hier archical or gan izat ion p rov ides such adv ant ag es as ease of m anag em ent , flexib ilit y , and a redu ct ion in un necessar y t r af fic. Thu s, t he I nt er nat ional Or ganizat ion for St andar dizat ion ( I SO) has adop t ed a num b er of t er m inology

  • Table of Content s

  conv en t ions f or add ressin g n et wor k ent it ies. Key t erm s d ef ined in t his sect ion in clud e end sy st em

  • I ndex ( ES) , int erm ediat e sy st em ( I S) , area, an d aut onom ous sy st em ( AS) .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion An ES is a net w or k dev ice t h at d oes not p er f orm r out ing or ot h er t raf fic f or w ard in g fun ct ion s.

  By Cisco Systems, Inc.

  Ty pical ESs in clud e such d ev ices as t erm inals, per sonal com put er s, and pr int er s. An I S is a net w or k dev ice t h at p er f orm s r out in g or ot her t r aff ic- for w ard ing fu nct ions. Ty pical I Ss inclu de

  Pub lish er: Cisco Press

  such devices as r out er s, sw it ches, and br idges. Tw o t yp es of I S net w ork s ex ist : int r adom ain I S

  Pub Dat e: Sep tem ber 1 1, 2 003

  and int er dom ain I S. An in t rad om ain I S com m unicat es w it hin a single au t onom ous sy st em , w h ile

  I SBN: 1- 58 705 -1 19 -2

  an int er dom ain I S com m unicat es w it hin and bet w een aut onom ous sy st em s. An ar ea is a logical

  Pages: 11 28

  gr oup of net w or k seg m en t s and t heir at t ach ed dev ices. Ar eas are sub div isions of aut onom ous syst em s ( AS's) . An AS is a collect ion of net w ork s u nder a com m on adm inist r at ion t h at shar e a com mon r out ing st r at egy . Aut on omou s syst em s ar e subd iv ided int o ar eas, and an AS is som et im es called a d omain. Figur e 1- 1 2 illust r at es a h ier ar ch ical net w ork and it s comp onent s.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  

Figu r e 1 - 1 2 . A H ie r ar ch ical Ne t w or k Cont ai ns N um e r ou s Com p on e nt s

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Connection-Oriented and Connectionless Network Services

  I n general, t ran sp ort pr ot ocols can be char act er ized as bein g eit h er con nect ion - orient ed or

  • I ndex

  Table of Content s

  connect ionless. Connect ion- or ien t ed serv ices m u st fir st est ablish a connect ion w it h t he desir ed

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  ser v ice befor e passing any dat a. A conn ect ionless ser v ice can sen d t he dat a w it hout any n eed t o

  est ablish a con nect ion f ir st . I n gener al, con nect ion - or ient ed ser v ices p rov ide som e level of deliver y gu aran t ee, w h er eas connect ionless ser vices do not .

  By Cisco Systems, Inc.

  Con nect ion - orient ed ser v ice in volv es t hr ee phases: connect ion est ablishm ent , d at a t r ansf er , an d

  Pub lish er: Cisco Press connect ion t er m inat ion.

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

  Du ring conn ect ion est ab lishm ent , t he end nod es m ay r eser v e r esour ces for t he connect ion. Th e end nodes also m ay n eg ot iat e and est ablish cer t ain crit er ia f or t he t ran sf er, su ch as a w indow Pages: 11 28 size used in TCP con nect ion s. This r esou rce r eser vat ion is on e of t he t h ings ex ploit ed in som e denial of ser vice ( DOS) at t ack s. An at t ack ing syst em w ill send man y r eq uest s for est ablishing a connect ion but t hen w ill never com plet e t he conn ect ion. The at t ack ed com put er is t hen left w it h r esour ces allocat ed for man y nev er - com plet ed connect ions. Then, w hen an end nod e t r ies t o com plet e an act u al connect ion, t h er e ar e n ot enoug h resour ces f or t h e valid connect ion. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The d at a t ran sf er phase occur s w hen t he act ual dat a is t r ansmit t ed ov er t he conn ect ion. D ur ing dat a t r ansfer , m ost conn ect ion- or ient ed ser vices w ill mon it or for lost pack et s and hand le r esendin g t hem. The pr ot ocol is g en er ally also r esp onsib le for p ut t ing t h e pack et s in t h e r ig ht

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom seq uence befor e p assing t he dat a up t he p rot ocol st ack . nov ice t o ex pert .

  When t he t ran sf er of dat a is com p let e, t h e en d nodes t er min at e t he con nect ion and r elease New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP r esour ces r eserv ed for t h e connect ion.

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Con nect ion - orient ed net w or k ser v ices hav e m or e ov er head t han connect ionless ones. Con nect ion - orient ed ser v ices m ust negot iat e a con nect ion , t r ansfer d at a, and t ear dow n t h e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . connect ion, w h er eas a conn ect ionless t r ansfer can sim ply send t he d at a w it h out t he add ed ov er head of creat ing and t ear ing dow n a conn ect ion. Each h as it s place in int ern et wor k s.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Internetw ork Addressing

  I n t ern et w or k ad dr esses

  id en t ify d ev ices separ at ely or as m emb er s of a gr oup. Addr essing sch em es v ar y dependin g on t h e pr ot ocol fam ily and t h e OSI lay er . Th r ee t yp es of in t er net w or k add resses ar e com m only used: dat a link lay er add resses, Media Access Cont rol ( MAC)

  • Table of Content s add resses, an d n et w or k lay er addr esses.

  I ndex •

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. Data Link Layer Addresses

  Pub lish er: Cisco Press

  A dat a link lay er addr ess u niqu ely ident if ies each phy sical net w ork con nect ion of a net w ork

  Pub Dat e: Sep tem ber 1 1, 2 003

  dev ice. Dat a- lin k addr esses som et im es ar e r ef err ed t o as ph ysical or har dw ar e ad dr esses. D at a-

  I SBN: 1- 58 705 -1 19 -2

  link add r esses usually ex ist w it hin a flat ad dr ess sp ace an d hav e a pr e- est ablish ed and t y pically

  Pages: 11 28 fix ed r elat ionship t o a specif ic device.

  En d sy st em s g en er ally hav e only on e ph ysical net w or k con nect ion an d t hus h ave only one d at a- link add r ess. Rou t er s an d ot her int er net w ork ing dev ices t y pically hav e m ult iple ph ysical net w or k connect ions an d t h er efor e h ave m u lt ip le dat a- link ad dr esses. Figur e 1- 1 3 illust r at es how each int er face on a d ev ice is uniq uely id en t ified by a d at a- link add r ess. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  

Figu r e 1 - 1 3 . Ea ch I n t e r f ace on a D ev ice I s Un iq ue ly I den t i f ie d by a

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

Da t a - Lin k A ddr e ss.

nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  

[ View full size im age]

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  MAC Addresses Media Access Con t r ol ( MAC) ad dr esses consist of a sub set of dat a link lay er add resses. MAC

  Figur e 1- 1 4 illust r at es t he relat ionship bet w een MAC addr esses, dat a- lin k addr esses, and t he I EEE sub lay er s of t he d at a link lay er.

  

Figu r e 1 - 1 4 . M A C Add r esse s, Da t a -Li nk Add r esse s, an d t he I EEE

Subl ay er s of t he D at a Lin k La y er Ar e A ll Re la t e d

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. MAC add resses ar e 4 8 b it s in leng t h and are ex pr essed as 12 hex adecim al d ig it s. The f irst 6 hex adecim al d igit s, w hich ar e ad min ist er ed by t he I EEE, ident if y t he man uf act u rer or vend or and

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom t hu s comp r ise t h e Or gan izat ion ally Uniq ue I dent if ier ( OUI ) . Th e last 6 hex adecim al d ig it s nov ice t o ex pert . com pr ise t h e int er face ser ial n um ber , or anot h er valu e adm inist er ed by t h e sp ecific v endor . MAC add resses som et imes ar e called bu rn ed - in add r esses ( BI As) b ecau se t hey are bur ned int o read-

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP only m em ory ( ROM) and ar e copied int o r andom - access m em ory ( RAM) w hen t h e int er face card init ializes. Figur e 1- 1 5 illust r at es t he MAC ad dr ess f or mat .

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

Figu r e 1 - 1 5 . Th e M AC A ddr ess Cont a in s a Un iqu e For m a t of

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

He x ade ci m al Di gi t s

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Mapping Addresses

  Becau se in t ern et w or k s gener ally use net w ork addr esses t o rou t e t r aff ic ar ound t h e net w ork , t her e is a need t o map n et w or k add r esses t o MAC add resses. Wh en t h e net w or k layer has det er min ed t he dest in at ion st at ion' s n et w or k add r ess, it m ust for w ar d t he inf orm at ion ov er a

  Table of Content s •

  ph ysical net w or k using a MAC ad dr ess. Dif fer en t pr ot ocol suit es u se d iff er ent met h ods t o perf or m

  • I ndex t his m ap ping, but t he most popu lar is Addr ess Resolu t ion Pr ot ocol ( ARP) .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Dif ferent pr ot ocol suit es u se d iff er ent met hod s for det erm ining t h e MAC addr ess of a dev ice. Th e follow ing t hr ee m et hods ar e u sed m ost of t en . Add ress Resolu t ion Pr ot ocol ( ARP) m aps net w ork add resses t o MAC add resses. The Hello p rot ocol en ables net w ork devices t o lear n t h e MAC

  Pub lish er: Cisco Press

  add resses of ot h er net w ork devices. MAC ad dr esses eit her ar e em bedd ed in t he net w ork lay er

  Pub Dat e: Sep tem ber 1 1, 2 003 add ress or ar e gener at ed by an algor it hm .

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Add ress Resolu t ion Prot ocol ( ARP) is t he m et hod used in t he TCP/ I P suit e. When a n et wor k dev ice n eeds t o send dat a t o an ot her dev ice on t h e sam e n et wor k , it kn ows t he sour ce and dest inat ion net w or k addr esses f or t he d at a t r an sf er . I t m ust som eh ow m ap t he d est inat ion add ress t o a MAC add ress befor e f or w ard in g t he dat a. Fir st , t h e sen ding st at ion w ill check it s ARP t able t o see if it has alr ead y discov er ed t his dest in at ion st at ion' s MAC add ress. I f it has not , it w ill send a b road cast on t he net w or k w it h t he d est inat ion st at ion' s I P add r ess cont ained in t he The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of br oadcast . Ever y st at ion on t h e net w or k r eceiv es t he br oadcast and com par es t he em bedded I P essent ial an d cu t t ing- edg e t ech nologies. add ress t o it s ow n. On ly t he st at ion w it h t he m at ching I P ad dr ess r eplies t o t h e sen ding st at ion w it h a pack et cont ainin g t he MAC add ress for t he st at ion. The f ir st st at ion t h en add s t his

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom inf orm at ion t o it s ARP t able for fut ur e r ef er ence and pr oceed s t o t ran sf er t he d at a. nov ice t o ex pert . When t he dest in at ion d ev ice lies on a rem ot e net w or k, one b ey ond a rou t er , t he pr ocess is t he

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP sam e ex cep t t h at t he sen ding st at ion send s t he ARP r equest f or t he MAC ad dr ess of it s default gat ew ay . I t t h en f orw ar ds t he inf or mat ion t o t hat dev ice. The default gat ew ay w ill t hen for w ar d

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age t he in for m at ion over w hat ev er net w or ks n ecessar y t o deliv er t he packet t o t h e net w or k on wh ich t he dest in at ion d ev ice r esides. The r out er on t h e dest in at ion device' s net w or k t h en uses ARP t o Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . obt ain t h e MAC of t he act ual dest in at ion d ev ice and deliver s t he packet .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  The Hello p rot ocol is a net w or k layer p rot ocol t hat en ables net w ork devices t o ident if y one enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing anot h er and indicat e t h at t h ey ar e st ill f unct ional. W hen a new end syst em p ower s up , for t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing exam ple, it br oadcast s hello m essages ont o t h e net w ork . D ev ices on t h e net w or k t hen ret u rn indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . hello r eplies, an d h ello messag es are also sent at sp ecific in t er v als t o in dicat e t hat t hey ar e st ill Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, fu nct ional. Net w or k devices can lear n t he MAC add resses of ot h er devices by ex amin in g Hello and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all pr ot ocol p ack et s. net w or kin g p rof essionals, r egar dless of ex pert ise.

  Thr ee pr ot ocols use pr edict able MAC add resses. I n t hese pr ot ocol suit es, MAC addr esses ar e Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e pr edict able because t he net w ork lay er eit her emb ed s t he MAC ad dr ess in t he net w ork lay er har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on add ress or u ses an algor it hm t o det er min e t he MAC ad dr ess. The t hr ee pr ot ocols are Xer ox a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Net w ork Sy st ems ( XNS) , Nov ell I nt er net w or k Packet Ex ch ange ( I PX) , and DECnet Ph ase I V. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

Network Layer Addresses

  pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. A net w or k lay er add ress id en t ifies an en t it y at t he net w or k layer of t h e OSI lay ers. Net w or k add resses u su ally ex ist w it hin a h ier ar ch ical addr ess sp ace and som et im es are called v ir t ual or

  logical addr esses . or on gr oup ings t hat h ave no p hy sical b asis ( t he dev ice is par t of an App leTalk zone) . End syst em s r eq uir e one n et w or k lay er addr ess for each net w ork lay er pr ot ocol t h at t h ey sup por t . ( This assum es t hat t he device has on ly one p hy sical net w or k connect ion. ) Rout er s and ot her int er net w ork ing dev ices r equir e one net w ork lay er add ress per ph ysical net w or k connect ion for each n et w or k lay er pr ot ocol suppor t ed. For ex am ple, a r out er w it h t h ree int er faces each r un ning App leTalk , TCP/ I P, an d OSI m ust h ave t hr ee net w ork lay er add resses f or each int er face. The r out er t h er efor e has nine n et w or k lay er addr esses. Figur e 1- 1 6 illust r at es how each net w or k int er face m ust be assig ned a net w or k addr ess for each pr ot ocol supp ort ed .

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 1 - 1 6 . Ea ch Ne t w or k I nt er f ace M ust Be Assign ed a Ne t w or k

Ad dr ess f or Ea ch Pr ot ocol Su ppor t e d

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

Hierarchical Versus Flat Address Space

  pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient I nt er net w ork addr ess sp ace t yp ically t ak es one of t w o for m s: hier archical ad dr ess space or f lat decisions for t h eir net w ork s. add ress space. A hierar chical ad dr ess space is org anized int o nu mer ous sub gr oup s, each successiv ely nar r ow in g an ad dr ess u nt il it point s t o a sing le device ( in a m ann er sim ilar t o st r eet add resses) . A flat addr ess sp ace is org anized int o a sing le gr oup ( in a m ann er sim ilar t o U. S. Social Secu rit y n um ber s) . and r ecall is sim plified using com par ison operat ion s. For ex am ple, " I reland " in a st r eet addr ess elim inat es an y ot her coun t ry as a p ossible locat ion. Figur e 1- 1 7 illust r at es t he diff er ence bet w een hier ar ch ical an d flat ad dr ess sp aces.

  

Figu r e 1 - 1 7 . H ie r ar ch ical a nd Fl at A ddr e ss Spa ces D if f er in Com par i son

O pe r at i ons

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  

[ View full size im age]

By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

Address Assignments indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Add resses ar e assigned t o d ev ices as one of t w o t yp es: st at ic and dy nam ic. St at ic add resses ar e and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all assig ned b y a n et w or k ad min ist r at or accor ding t o a pr econ ceiv ed int er net w or k addr essing p lan . net w or kin g p rof essionals, r egar dless of ex pert ise. A st at ic ad dr ess d oes not ch ange u nt il t h e net w or k adm inist r at or m anually chan ges it . Dy nam ic

  add resses

  ar e ob t ained b y dev ices w hen t hey at t ach t o a net w or k, by m eans of som e pr ot ocol- Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e specif ic pr ocess. A d ev ice using a d yn amic ad dr ess of t en has a diff er ent addr ess each t im e t hat it har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on connect s t o t he n et w or k . Som e net w or ks use a serv er t o assign add resses. Ser ver - assign ed a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions add resses ar e r ecy cled f or r eu se as devices discon nect . A d ev ice is t her ef or e lik ely t o h ave a t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . dif fer en t add r ess each t im e t h at it con nect s t o t he net w or k. Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

Addresses Versus Names pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s

  I nt er net w ork devices usually hav e bot h a nam e and an add ress associat ed wit h t h em . I nt er net w ork nam es t yp ically ar e locat ion- independ en t an d r em ain associat ed w it h a dev ice w her ev er t hat dev ice m ov es ( for ex am ple, fr om on e buildin g t o anot h er ) . I n t er n et w or k add resses, n ames ar e usually m app ed t o net w or k addr esses t h rou gh some p r ot ocol. The I nt er net u ses Dom ain Nam e Syst em ( DNS) t o map t h e nam e of a d ev ice t o it s I P addr ess. For exam ple, it ' s easier f or y ou t o r em em ber w w w .cisco. com inst ead of som e I P ad dr ess. Th er efor e, y ou t yp e w w w. cisco. com int o you r br ow ser wh en y ou w ant t o access Cisco's w eb sit e. You r com put er p er for m s a DNS look up of t he I P addr ess for Cisco' s w eb ser v er and t hen com mu nicat es wit h it usin g t he n et w or k add r ess.

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Flow Control Basics

  Flow cont r ol is a fun ct ion t h at p rev en t s net w or k congest ion b y ensur ing t hat t r ansmit t in g devices do not over w helm r eceiving dev ices w it h dat a. A hig h- speed com put er , f or exam ple, m ay gener at e t r aff ic fast er t h an t he net w or k can t ran sf er it , or f ast er t han t he d est inat ion dev ice can

  Table of Content s •

  r eceive and pr ocess it . Th e t hr ee comm only u sed m et hods f or han dling net w or k congest ion ar e

  I ndex • bu ff er ing , t r ansm it t in g sou rce- quench m essages, and w indow ing .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Buf fer ing is used b y net w ork devices t o t em por ar ily st or e b ur st s of ex cess d at a in m em or y u nt il By Cisco Systems, Inc. t hey can be p rocessed. Occasional d at a b ur st s are easily han dled by buf fer ing. Excess dat a bu rst s can exh aust m em ory , h owev er, for cin g t he dev ice t o discard an y addit ional dat ag ram s

  Pub lish er: Cisco Press t hat ar r iv e.

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

  Sour ce- quench messages ar e used b y receiv ing dev ices t o help p rev ent t heir buf fer s fr om

  Pages: 11 28

  ov er f low ing . The receiv ing dev ice sends sou rce- quench m essages t o requ est t hat t he sour ce r ed uce it s cur r en t r at e of d at a t r ansm ission. Fir st , t he receiv ing dev ice b eg ins discard ing r eceived dat a due t o ov erf lowin g b uf fers. Second, t he r eceiv ing device begin s send ing sou r ce- qu en ch m essages t o t he t ran sm it t ing d ev ice at t h e r at e of one m essag e for each packet dr opped. The sou rce dev ice receiv es t he sour ce- quench m essages and low er s t he dat a r at e un t il it st op s r eceivin g t h e m essages. Fin ally , t h e sour ce device t hen gr adu ally in cr eases t he dat a r at e as long The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of as n o fu r t her sour ce- q uench r equest s ar e r eceived. essent ial an d cu t t ing- edg e t ech nologies. Wind owin g is a flow - cont r ol schem e in wh ich t h e sou rce d ev ice r eq uires an ack now led gm en t fr om t he dest inat ion aft er a cer t ain num b er of p ack et s hav e b een t r ansm it t ed . Wit h a w ind ow

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom size of 3, t h e sour ce requ ires an ackn ow ledg m en t af t er send ing t hr ee packet s, as f ollows. Fir st , nov ice t o ex pert . t he sou rce d ev ice send s t hr ee pack et s t o t h e dest inat ion device. Then, af t er r eceiving t h e t hr ee pack et s, t he dest inat ion dev ice sends an ack now led gm ent t o t h e sou rce. The sou rce r eceiv es t he

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP ackn ow ledg m en t and sends t hr ee mor e p ack et s. I f t he dest inat ion does not r eceive one or m or e of t he packet s f or som e reason, such as ov erf low in g b uf fer s, it does not r eceive en ough pack et s Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age t o send an ackn ow ledg ment . The sour ce t hen r et ran sm it s t h e pack et s at a redu ced t r ansm ission

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . r at e.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Error-Checking Basics

  Er r or - ch eck ing sch em es det erm ine wh et her t r ansm it t ed dat a has becom e cor ru pt or ot her w ise dam aged w hile t r av eling fr om t he sour ce t o t he dest inat ion. Er ror ch eck ing is imp lem ent ed at sev er al of t he OSI layer s.

  • Table of Content s
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ndex

  On e com m on err or - check ing sch em e is t he cyclic r ed und ancy check ( CRC) , w hich d et ect s an d

  discard s corr up t ed d at a. Er r or - cor r ect ion f unct ions ( su ch as d at a r et r ansmission) ar e left t o high er - lay er pr ot ocols. A CRC v alue is g en er at ed by a calculat ion t hat is per for m ed at t he sour ce

  By Cisco Systems, Inc.

  dev ice. Th e dest in at ion d ev ice comp ares t h is valu e t o it s own calculat ion t o det er min e w het her err or s occur red du ring t r ansm ission. Fir st , t h e sou r ce d ev ice per for m s a p redet er min ed set of

  Pub lish er: Cisco Press

  calcu lat ion s ov er t he cont ent s of t he pack et t o be sent . Th en , t he sou rce p laces t he calculat ed

  Pub Dat e: Sep tem ber 1 1, 2 003

  v alue in t he p ack et an d sends t he p ack et t o t he d est inat ion . The d est inat ion p er for m s t h e same

  I SBN: 1- 58 705 -1 19 -2

  pr edet erm ined set of calculat ions over t h e cont ent s of t h e pack et and t hen comp ar es it s

  Pages: 11 28

  com put ed valu e w it h t hat cont ain ed in t he p acket . I f t he values ar e equ al, t he p ack et is considered v alid . I f t he v alues ar e unequ al, t he p ack et cont ain s err or s and is d iscar ded.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Multiplexing Basics

  Mu lt iplex in g

  is a pr ocess in w hich mu lt iple dat a ch annels ar e com bined in t o a sin gle dat a or ph ysical chann el at t h e sour ce. Mu lt iplex ing can be im plement ed at any of t he OSI lay er s. Con ver sely , dem ult ip lexing is t he pr ocess of separ at ing m ult iplexed dat a chann els at t he

  Table of Content s •

  dest inat ion. One ex amp le of m ult iplex ing is w hen dat a fr om m ult ip le applicat ions is m ult iplex ed

  I ndex • int o a single low er - layer dat a pack et . Figur e 1- 1 8 illust r at es t his ex am ple.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 1 - 1 8 . M u lt ipl e Appl icat ions Ca n B e M ul t ip le xe d i nt o a Sin gle

Pub lish er: Cisco Press

  

Low er - La ye r D at a Pack e t

Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Anot h er ex am ple of m ult iplex in g is wh en d at a f rom mu lt iple dev ices is com bined in t o a sin gle ph ysical chann el ( using a dev ice called a m ult iplexer ) . Figur e 1- 1 9 illust r at es t his ex am ple.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

Figu r e 1 - 1 9 . M u lt ipl e De vi ces Ca n Be M ul t ip le xe d i nt o a Sin gle Ph ysica l

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Cha nn el net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. A m ult ip lexer is a ph ysical layer d ev ice t hat comb in es mu lt iple dat a st ream s int o one or mor e out p ut ch annels at t he sour ce. Mult iplex er s d em ult iplex t h e ch annels int o m ult iple dat a st r eam s at t he r emot e en d and t hus max im ize t he u se of t he ban dw idt h of t he phy sical medium by

  Som e m et hods u sed for mu lt iplex ing dat a ar e t im e- d ivision m u lt ip lex ing ( TDM) , asy nchr on ous t im e- division mu lt ip lex ing ( ATDM) , fr equency - div ision m ult iplexing ( FDM) , and st at ist ical m ult iplexin g. I n TDM, inf or mat ion f rom each dat a chann el is allocat ed band wid t h based on pr eassign ed t im e slot s, regar d less of w het her t h er e is d at a t o t r ansmit . I n ATDM, inf orm at ion fr om d at a chan nels is allocat ed ban dw idt h as needed by using dy nam ically assign ed t im e slot s. I n FDM, in for m at ion fr om each dat a ch annel is allocat ed b andw idt h b ased on t he signal fr equency of t h e t r aff ic. I n

  Table of Content s •

  st at ist ical mu lt ip lex ing, band w id t h is dy nam ically allocat ed t o any d at a chan nels t hat hav e

  I ndex • inf orm at ion t o t ran sm it .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Standards Organizations

  A w ide var iet y of or ganizat ions con t r ib ut e t o int er net w ork ing st andar d s by p rov iding f oru ms for discussion , t ur ning inf or mal discu ssion int o for m al specif icat ion s, and pr olif erat in g specificat ions aft er t hey ar e st andar dized. Most st an dar ds or gan izat ions cr eat e f or m al st andar ds by using specif ic pr ocesses: or ganizing ideas, discu ssing t h e appr oach, d ev eloping dr af t st and ard s, vot in g on all or cer t ain asp ect s of t he st an dar ds, and t h en f orm ally r eleasing t he com plet ed st and ar d t o t he public. Som e of t he b est - k now n st and ard s or ganizat ions t hat con t r ib ut e t o int er net w ork ing st and ard s include t hese:

  • Table of Content s
  • I ndex

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Ele ct roni c I nd ust ri es A ssocia t ion ( EI A)

  — I AB is a g rou p of in t er net w or k r esear ch er s w h o discuss issu es p er t in en t t o t he I nt er net and set I n t ern et policies t h r ough decisions and t ask for ces. The I AB desig nat es some Req uest For Com m ent s ( RFC) docum ent s as I nt ern et st and ard s, includin g Tr ansm ission Cont rol Prot ocol/ I nt er net Pr ot ocol ( TCP/ I P) and t h e Simp le Net w or k Man agement Pr ot ocol ( SNMP) .

  I nt e rn et Act iv i t ie s Boar d ( I AB)

  — For m erly called t h e Com m it t ee for I nt er nat ion al Telegr aph an d Telep hone ( CCI TT) , I TU- T is now an in t er n at ional or gan izat ion t h at d ev elop s com mu nicat ion st and ar ds. The I TU- T d ev elop ed X. 25 and ot h er com m un icat ions st an dar ds.

  I nt e rn at i ona l Tel ecom m uni ca t i on U ni on Te le com m un ica t ion St a nda rd iz a t ion Se ct or ( I TU- T)

  — I EEE is a p rof essional or ganizat ion t hat def in es net w ork ing and ot h er st an dar ds. The I EEE developed t he w idely used LAN st and ard s I EEE 8 02. 3 and I EEE 80 2. 5.

  I nst i t ut e of Ele ct ri ca l a nd Ele ct roni c Engi ne er s ( I EEE)

  — EI A specif ies elect rical t r ansm ission st andar d s, in clu ding t hose u sed in n et w or k ing. The EI A developed t he w idely used EI A/ TI A- 23 2 st an dar d ( for m er ly k now n as RS- 2 32) .

  — ANSI , w h ich is also a mem ber of t h e I SO, is t h e coord inat ing bod y for v olun t ary st an dar ds g rou ps w it hin t h e Un it ed St at es. ANSI dev elop ed t h e Fib er D ist r ibu t ed Dat a I nt er face ( FDDI ) and ot her com mu nicat ions st andar d s.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  — I SO is an int er nat ional st andar d s or ganizat ion r espon sible f or a w id e r ange of st an dar ds, including m any t hat are r elev ant t o net w or k in g. I t s b est - k now n cont r ibut ion is t h e dev elopm ent of t he OSI r ef erence m odel an d t he OSI pr ot ocol su it e.

  I nt e rn at i ona l Org an iz at i on for St a nda r diz a t ion ( I SO)

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  Am e ri ca n N at iona l St a nda rd s I nst it ut e ( AN S I )

Summary

  This chap t er int r oduced t he b uilding blocks on w h ich int er net w ork s ar e b uilt . Under st an ding w her e comp lex p ieces of int ern et wor k s f it int o t he OSI m odel w ill help y ou un derst and t h e concep t s bet t er . I nt er net w ork s ar e com plex sy st ems t hat , wh en v iew ed as a w h ole, ar e t oo m uch

  • Table of Content s

  t o und er st and. Only b y br eaking t h e net w or k dow n int o t he concept ual pieces can it be easily

  • I ndex

  un derst ood . As y ou r ead and exp er ien ce int ern et wor k s, t r y t o t hink of t h em in t er m s of OSI

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion lay er s and concept ual pieces.

  By Cisco Systems, Inc.

  Under st anding t h e int eract ion bet w een v ar iou s layer s and pr ot ocols m ak es d esign ing, conf ig ur ing, and diagnosing int er net w or ks p ossible. Wit h out under st andin g of t h e bu ild in g

  Pub lish er: Cisco Press block s, you cannot un derst an d t h e int er act ion bet w een t h em .

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1 :

  What ar e t he lay er s of t he OSI m odel?

  • Table of Content s
  • 2 : I ndex

  Which layer d et er m in es pat h select ion in an int ern et wor k ?

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion 3 :

  What t y pes of t hin gs ar e def in ed at t he p hy sical lay er ? By Cisco Systems, Inc.

  4 :

  What is one met hod of m app ing net w ork addr esses t o MAC ad dr esses?

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 5 :

  Which includes m or e over head, con nect ion - orient ed or connect ionless ser vices?

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information

  • Cisco' s w eb sit e ( w w w .cisco. com ) is a w ond er f ul sour ce for mor e inf or mat ion ab out t hese t opics. The D ocu m en t at ion sect ion includ es in - dept h discussion s on man y of t he t opics cov ered
  • I ndex •

  Table of Content s in t his chapt er .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion • Tear e, Diane. Designing Cisco Net w or ks. I nd ianapolis: Cisco Pr ess, Ju ly 199 9.

  By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 2. Introduction to LAN Protocols Obj e ct i ve s

  • Table of Content s Lear n about diff erent LAN pr ot ocols.

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Under st and t he d if fer en t m et hod s used t o deal w it h m ed ia cont ent ion.

  By Cisco Systems, Inc.

  Lear n about diff erent LAN t opologies.

  Pub lish er: Cisco Press

  This chap t er int r oduces t he var ious m edia- access m et hods, t ran sm ission m et hods, t op ologies,

  Pub Dat e: Sep tem ber 1 1, 2 003

  and dev ices u sed in a local- ar ea n et w or k ( LAN) . Topics add ressed focus on t he m et hods and

  I SBN: 1- 58 705 -1 19 -2

  dev ices used in Et hern et / I EEE 80 2. 3, Tok en Ring/ I EEE 8 02. 5 , and Fib er Dist rib ut ed D at a

  Pages: 11 28

  I nt er face ( FDDI ) . Su bseq uent ch apt er s in Par t I I , " LAN Pr ot ocols, " addr ess sp ecific p rot ocols in m or e det ail. Figur e 2- 1 illust r at es t he basic lay out of t hese t hr ee im plement at ion s.

  

Figu r e 2 - 1 . Thr e e LAN I m ple m e nt a t i ons A r e Use d M ost Com m on ly

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is a LAN?

  A LAN is a high - speed dat a net w or k t hat cover s a r elat ively sm all geogr aphic area. I t t yp ically connect s w or kst at ion s, personal com pu t ers, p rin t er s, serv ers, an d ot her dev ices. LANs of fer com put er u ser s m any adv ant ages, in clu ding shar ed access t o dev ices and app licat ions, f ile

  Table of Content s •

  exchan ge b et w een conn ect ed user s, an d com m unicat ion bet w een user s v ia elect r on ic mail and

  I ndex • ot her ap plicat ion s.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Protocols and the OSI Reference Model

  LAN pr ot ocols fun ct ion at t he low est t w o layer s of t he OSI r ef er ence m odel, as d iscussed in

  

Ch apt er 1 , " I nt er net w or kin g Basics, " bet w een t he p hy sical lay er and t he dat a link lay er . Figur e

2- 2 illust r at es how sev er al p opular LAN p rot ocols m ap t o t h e OSI r efer en ce mod el.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 2 - 2 . Pop ul ar LAN Pr ot ocol s M ap ped t o t he O SI Re f er e nce M od el

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  LAN Media-Access Methods Media con t en t ion occur s w hen t w o or mor e n et w or k d ev ices h ave d at a t o sen d at t h e sam e t im e.

  Becau se mu lt ip le devices cannot t alk on t he n et wor k sim ult aneously , some t yp e of m et h od m u st be u sed t o allow one dev ice access t o t h e net w or k media at a t im e. This is don e in t wo m ain

  Table of Content s • w ay s: carr ier sen se m u lt ip le access collision d et ect ( CSMA/ CD ) and t ok en p assing . I ndex •

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I n net w ork s u sing CSMA/ CD t echn olog y such as Et her net , n et w or k d ev ices cont en d f or t he net w or k m ed ia. When a d ev ice has dat a t o send , it f ir st list ens t o see if any ot her d ev ice is

  By Cisco Systems, Inc.

  cur r en t ly using t he n et w or k . I f not , it st art s sen ding it s dat a. Aft er f in ish ing it s t r ansm ission, it list en s again t o see if a collision occur r ed. A collision occur s w hen t w o d ev ices send dat a

  Pub lish er: Cisco Press

  simu lt aneously. W hen a collision h appens, each device w ait s a ran dom lengt h of t im e b ef ore

  Pub Dat e: Sep tem ber 1 1, 2 003 r esendin g it s dat a. I n m ost cases, a collision w ill not occu r again bet w een t h e t w o d ev ices.

  I SBN: 1- 58 705 -1 19 -2

  Becau se of t his t y pe of n et w or k cont ent ion , t he b usier a net w or k becom es, t h e m ore collision s

  Pages: 11 28

  occu r . This is w hy perf or man ce of Et her net d eg rad es rap idly as t he num ber of d ev ices on a single n et w or k incr eases. I n t ok en - passing n et wor k s such as Tok en Ring an d FDD I , a special net w ork packet called a t ok en is passed ar oun d t he net w or k fr om device t o device. When a dev ice has dat a t o send , it m ust w ait u nt il it has t h e t ok en and t h en sends it s dat a. Wh en t h e dat a t r ansmission is com plet e, t he The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t ok en is r eleased so t hat ot her dev ices m ay use t h e net w or k m ed ia. The m ain adv ant age of essent ial an d cu t t ing- edg e t ech nologies. t ok en - passin g net w ork s is t h at t h ey are det er m inist ic. I n ot h er w or ds, it is easy t o calcu lat e t he m axim um t ime t hat w ill pass befor e a device has t he op por t unit y t o sen d dat a. Th is ex plains t he pop ular it y of t oken- passing n et w or k s in som e r eal- t ime env ir onm ent s such as fact or ies, wh er e

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom m achinery mu st be cap able of comm un icat in g at a det er m inable in t er v al. nov ice t o ex pert .

  For CSMA/ CD n et wor k s, swit ches segm ent t he net w or k int o m ult iple collision dom ains. This New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP r ed uces t he n um ber of dev ices per n et w or k segm en t t h at m ust cont end for t he m edia. By creat ing sm aller collision dom ains, t h e per for m ance of a n et w or k can be incr eased sig nificant ly Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age w it hout r equir ing addr essing chan ges.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Nor mally CSMA/ CD net w or ks ar e h alf- du plex, meaning t h at w h ile a dev ice sends in for m at ion, it

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  cannot r eceive at t h e t ime. W hile t hat device is t alk ing, it is incapab le of also list ening f or ot her enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t r aff ic. This is m uch lik e a w alk ie- t alkie. Wh en one person w ant s t o t alk , he p resses t he t r ansm it t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing bu t t on and begins sp eak ing. While he is t alk ing , no one else on t h e same fr equency can t alk. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . When t he send in g person is finished, he r eleases t he t r ansm it b ut t on and t h e fr equency is Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, av ailab le t o ot h er s. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. When sw it ch es ar e int rod uced , fu ll- dup lex op er at ion is possib le. Full- d uplex w or ks m u ch like a t elep hone—y ou can list en as w ell as t alk at t he sam e t im e. When a n et w or k d ev ice is at t ached Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e dir ect ly t o t he por t of a net w or k sw it ch, t he t w o devices m ay be capab le of operat in g in fu ll- har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on du plex mod e. I n f ull- dup lex m od e, perf or man ce can be in cr eased , bu t not qu it e as m uch as a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions som e lik e t o claim . A 100 - Mbp s Et h er net segm ent is cap able of t r ansm it t ing 200 Mb ps of d at a, t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . bu t on ly 100 Mb ps can t rav el in one d ir ect ion at a t im e. Becau se most dat a con nect ion s ar e Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy asym m et r ic ( w it h m or e dat a t r av eling in one dir ect ion t h an t he ot her ) , t h e gain is not as gr eat syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich as m any claim . How ev er , fu ll- d uplex oper at ion does increase t he t hr ough put of m ost pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease app licat ions becau se t he net w or k m ed ia is no longer shar ed. Tw o devices on a f ull- dup lex pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient connect ion can sen d dat a as soon as it is r ead y. decisions for t h eir net w ork s. Tok en - passin g n et wor k s such as Tok en Ring can also benefit fr om n et w or k sw it ch es. I n lar ge net w or ks, t he delay bet w een t u rn s t o t ran sm it may be signif ican t because t he t oken is passed ar ound t h e net w or k.

LAN Transmission Methods

  LAN dat a t r ansmission s fall in t o t hr ee classif icat ion s: un icast , m ult icast , and br oadcast . I n each t y pe of t r ansm ission, a single p ack et is sent t o on e or m or e nodes.

  • Table of Content s I n a un icast t r ansm ission , a sin gle pack et is sen t f r om t he sour ce t o a d est inat ion on a n et w or k .
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ndex

  First , t he sour ce node ad dr esses t he p acket b y using t he addr ess of t he dest inat ion nod e. Th e

  pack age is t h en sent on t o t he net w or k, and finally , t h e net w ork passes t h e pack et t o it s dest inat ion.

  By Cisco Systems, Inc.

  A m ult icast t r an sm ission con sist s of a sing le dat a packet t hat is cop ied and sent t o a sp ecific

  Pub lish er: Cisco Press

  subset of n odes on t he n et w or k . Fir st , t h e sour ce node ad dr esses t he p ack et b y using a m u lt icast

  Pub Dat e: Sep tem ber 1 1, 2 003

  add ress. The p ack et is t h en sent in t o t h e net w or k, w hich m ak es cop ies of t h e pack et and sen ds a

  I SBN: 1- 58 705 -1 19 -2 copy t o each nod e t hat is par t of t he m ult icast add ress. Pages: 11 28

  A br oadcast t ran sm ission con sist s of a sing le dat a packet t hat is cop ied and sent t o all n odes on t he net w ork . I n t hese t y pes of t r ansm issions, t he sou rce n ode add resses t he pack et by usin g t he br oadcast ad dr ess. Th e packet is t hen sent on t o t he net w or k, w hich m ak es cop ies of t h e pack et and sends a copy t o ev ery node on t h e net w or k.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Topologies

  LAN t opologies def in e t he m an ner in w h ich net w or k dev ices ar e or ganized. Fou r com m on LAN t opolog ies ex ist : bu s, ring , st ar , and t r ee. These t opologies ar e logical ar ch it ect ur es, but t he act ual d ev ices need not be p hy sically or ganized in t h ese conf igur at ions. Logical bu s and r in g

  • Table of Content s

  t opolog ies, f or exam ple, ar e com mon ly org anized p hy sically as a st ar . A bu s t opology is a linear

  I ndex •

  LAN arch it ect ur e in w hich t ran sm ission s fr om n et w or k st at ions pr opagat e t he lengt h of t h e

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  m ed ium an d ar e r eceiv ed by all ot her st at ions. Of t he t hr ee m ost w idely used LAN im plem ent at ion s, Et her net / I EEE 8 02. 3 net w or ks—includin g 1 00BaseT—im plem ent a b us By Cisco Systems, Inc. t opolog y, wh ich is illust r at ed in Figur e 2- 3 .

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

Figu r e 2 - 3 . Som e Ne t w or k s I m p le m en t a Local Bu s Topology

  Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. A r in g t op ology is a LAN arch it ect ur e t h at consist s of a ser ies of d ev ices conn ect ed t o on e anot h er

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom by u nidir ect ion al t r ansm ission lin ks t o for m a single closed loop. Bot h Tok en Ring/ I EEE 8 02. 5 nov ice t o ex pert . and FDDI net w ork s im plement a ring t op ology . Figur e 2- 4 d ep ict s a logical r ing t opolog y.

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  

Figu r e 2 - 4 . Som e Ne t w or k s I m p le m en t a Logical Ri ng Topology

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  A st ar t op ology is a LAN arch it ect ur e in w hich t he endp oint s on a n et wor k ar e conn ect ed t o a com mon cent r al hu b, or sw it ch, b y dedicat ed link s. Log ical bus an d ring t op ologies are oft en Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age im plem ent ed ph ysically in a st ar t opology , w hich is illu st r at ed in Figur e 2- 5 .

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

Figu r e 2 - 5 . A Logical Tr ee Topol ogy Ca n Con t a in M u lt i pl e Node s

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  A t r ee t opology is a LAN arch it ect ur e t h at is ident ical t o t h e bus t opology , except t hat br anches Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age w it h mu lt iple nod es ar e p ossible in t his case. Figur e 2- 5 illust r at es a log ical t ree t op olog y.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

LAN Devices

  Dev ices com mon ly used in LANs includ e r ep eat er s, hub s, LAN ex t ender s, br idges, LAN sw it ches, and r out er s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion NO TE By Cisco Systems, Inc.

  Repeat er s, hubs, an d LAN ex t en der s ar e discu ssed br ief ly in t h is sect ion. Th e fu nct ion

  Pub lish er: Cisco Press

  and oper at ion of br idges, swit ches, and r out er s ar e discussed gener ally in Ch apt er 4 ,

  Pub Dat e: Sep tem ber 1 1, 2 003

  " I nt r odu ct ion t o Cisco I OS Sof t w are, " an d Ch apt er 5 , " Br idg in g and Swit chin g Basics. "

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  A r ep eat er is a ph ysical layer d ev ice used t o int er con nect t he media segm ent s of an ex t en ded net w or k. A r epeat er essen t ially en ables a ser ies of cable seg ment s t o b e t r eat ed as a sin gle cable. Repeat ers receiv e signals f r om one n et w or k segm en t an d am p lif y, ret im e, and r et ran sm it t hose sign als t o anot her net w or k segm ent . These act ion s pr event sig nal d et er iorat ion caused b y The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of long cable lengt h s and lar ge nu mb er s of conn ect ed devices. Repeat er s ar e incapab le of essent ial an d cu t t ing- edg e t ech nologies. per for m ing com p lex f ilt er ing and ot h er t raf fic p rocessing . I n addit ion, all elect r ical sign als, includin g elect r ical dist ur ban ces an d ot her er r or s, ar e repeat ed and am plified. Th e t ot al n um ber of r ep eat er s and n et w or k segm en t s t hat can be connect ed is lim it ed d ue t o t im in g and ot her

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom issu es. Figur e 2- 6 illust r at es a r epeat er connect ing t w o n et w or k segm en t s. nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  

Figu r e 2 - 6 . A Re pea t e r Conn ect s Tw o Ne t w or k Segm e nt s

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease A hu b is a ph ysical layer d ev ice t hat connect s m ult iple user st at ions, each v ia a dedicat ed cable. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Elect rical int er connect ions ar e est ablish ed inside t he hu b. Hu bs ar e used t o cr eat e a ph ysical st ar decisions for t h eir net w ork s. net w or k w hile m aint aining t h e logical bus or r in g con figu rat ion of t h e LAN. I n som e r espect s, a hu b f un ct ion s as a m u lt ip ort r ep eat er .

  A LAN ext end er is a r em ot e- access m ult ilay er sw it ch t hat con nect s t o a host r ou t er . LAN ext end er s scale w ell becau se t he host r out er filt er s out unw an t ed br oad cast s an d m u lt icast s. How ev er , LAN ex t ender s ar e not capable of segm en t ing t r aff ic or creat ing secu rit y f ir ew alls.

  Figur e 2- 7 illust r at es m ult iple LAN ext end er s conn ect ed t o t h e host rou t er t hr ough a WAN.

  

Figu r e 2 - 7 . M ul t ip le LA N Ext e n der s Can Conn ect t o t he Host Rou t e r

Thr ou gh a W AN

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Review Questions 1 : Descr ibe t he t y pe of m edia access u sed by Et her net .

  Table of Content s • 2 : I ndex Descr ibe t he t y pe of m edia access u sed by Tok en Ring.

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  3 : Descr ibe u nicast , m ult icast , and br oadcast t r ansm issions.

  By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information

  • Cisco' s w eb sit e ( w w w .cisco. com ) is a w ond er f ul sour ce for mor e inf or mat ion ab out t hese t opics. The D ocu m en t at ion sect ion includ es in - dept h discussion s on man y of t he t opics cov ered
  • I ndex •

  Table of Content s in t his chapt er .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion • Tear e, Diane. Designing Cisco Net w or ks. I nd ianapolis: Cisco Pr ess, Ju ly 199 9.

  By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 3. Introduction to WAN Technologies

  • Table of Content s

  Obj e ct i ve s

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Becom e f am iliar w it h WAN t er m inology .

  By Cisco Systems, Inc.

  Lear n about diff erent t y pes of WAN conn ect ions.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Becom e f am iliar w it h dif fer en t t y pes of WAN eq uipm ent .

  I SBN: 1- 58 705 -1 19 -2

  This chap t er int r oduces t he var ious p r ot ocols an d t echn ologies used in w id e- area n et wor k ( W AN)

  Pages: 11 28

  env iron ment s. Topics su mm ar ized h er e includ e point - t o- point lin ks, cir cu it sw it ching, packet sw it ch in g, v ir t ual cir cu it s, dialup ser v ices, and WAN devices. Chapt er s in Par t I I I , " WAN Pr ot ocols, " addr ess sp ecific t echnolog ies in m or e det ail.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is a WAN?

  A WAN is a dat a comm u nicat ion s net w or k t hat cover s a r elat ively br oad geogr aph ic area and t hat of t en uses t r ansm ission facilit ies p rov ided by com mon car rier s, su ch as t elephon e com panies. WAN t echnologies g en er ally fu nct ion at t he low er t h ree lay er s of t he OSI r efer en ce

  • Table of Content s

  m odel: t h e phy sical layer , t he dat a link lay er , and t he net w ork lay er. Figur e 3- 1 illust r at es t he

  • I ndex r elat ion sh ip b et w een t he com mon WAN t echn ologies and t he OSI m odel.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 3 - 1 . W AN Techn ologi es O pe r at e at t h e Low est Lev el s of t h e O SI

Pub lish er: Cisco Press

  

M ode l

Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Point-to-Point Links

  A point - t o- poin t lin k p r ovides a sin gle, pr e- est ablished WAN com mu nicat ions pat h f r om t he cust om er pr em ises t hr ough a car r ier net w ork , such as a t eleph one com pany , t o a r em ot e net w or k. Point - t o- p oin t lines ar e usu ally leased f rom a car rier and t h us ar e of t en called leased

  • Table of Content s

  lines. For a poin t - t o- point line, t he car r ier allocat es pair s of w ir e and facilit y har dw ar e t o you r

  • I ndex

  line only . Th ese circu it s are generally p riced b ased on band wid t h requ ir ed and dist ance bet w een

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  t he t w o connect ed p oint s. Point - t o- point lin ks are g en er ally m or e ex pensiv e t han shar ed ser vices By such as Fr am e Relay . Cisco Systems, Inc. Figur e 3- 2 illust r at es a t yp ical p oint - t o- p oin t link t hr ough a WAN.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Figu r e 3 - 2 . A Ty pi cal Poi nt - t o- Poin t Lin k O pe r at e s Thr ou gh a W AN t o a

  I SBN: 1- 58 705 -1 19 -2

Re m ot e N et w or k

  Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Circuit Switching

  Sw it ch ed cir cuit s

  allow dat a conn ect ions t hat can b e init iat ed w hen needed an d t er m inat ed w hen com mu nicat ion is com plet e. This w or ks mu ch lik e a n orm al t elephon e line w or ks for v oice com mu nicat ion . I nt egr at ed Ser v ices Dig it al Net wor k ( I SDN) is a g ood ex am ple of circuit

  • Table of Content s

  sw it ch in g. Wh en a r out er has d at a f or a rem ot e sit e, t he sw it ched cir cu it is init iat ed w it h t he

  I ndex •

  circuit num b er of t he r em ot e net w ork . I n t he case of I SDN cir cu it s, t he d ev ice act ually places a

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  call t o t he t elep hone num ber of t h e r em ot e I SDN cir cuit . Wh en t h e t w o n et w or k s ar e connect ed By and aut hent icat ed , t hey can t r ansfer dat a. When t he d at a t r ansm ission is comp let e, t h e call can Cisco Systems, Inc. be t er m inat ed. Figur e 3- 3 illust r at es an ex am ple of t h is t yp e of cir cuit .

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

Figu r e 3 - 3 . A Ci r cui t - Sw it ch ed W AN Un der g oes a Pr oce ss Sim i la r t o

  Pages: 11 28

Tha t Use d for a Tel eph one Cal l

  

[ View full size im age]

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Packet Switching

  Packet sw it chin g

  is a WAN t echn olog y in wh ich user s shar e comm on carr ier r esour ces. Because t his allow s t h e carr ier t o m ak e m or e ef ficient u se of it s infr ast r uct ur e, t he cost t o t h e cust omer is gener ally mu ch b et t er t han w it h p oin t - t o- poin t lines. I n a pack et sw it ch in g set up , net w or ks hav e

  Table of Content s •

  connect ions int o t he car r ier ' s net w or k, and man y cust om er s shar e t h e carr ier' s net w or k . The

  I ndex •

  carr ier can t hen cr eat e v ir t u al cir cuit s b et ween cu st om er s' sit es by w h ich pack et s of dat a are

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  deliver ed f r om one t o t he ot her t hr oug h t he net w or k . The sect ion of t h e car r ier ' s net w or k t hat is By shar ed is of t en r efer r ed t o as a cloud. Cisco Systems, Inc. Som e exam ples of pack et - sw it ching n et w or k s include Asy nchr onou s Tran sfer Mode ( ATM) , Fr ame

  Pub lish er: Cisco Press

  Relay, Sw it ch ed Mu lt im egab it Dat a Ser v ices ( SMDS) , and X. 25 . Figur e 3- 4 sh ows an ex am ple

  Pub Dat e: Sep tem ber 1 1, 2 003 pack et - sw it ched cir cuit .

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 3 - 4 . Pa ck e t Sw it chi ng Tr an sfe r s Packe t s A cr oss a Ca r r ie r

Ne t w or k

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  

[ View full size im age]

essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. The v ir t ual con nect ion s bet w een cust om er sit es ar e oft en r eferr ed t o as a v ir t u al circuit . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  WAN Virtual Circuits A v ir t ual circuit is a logical circuit creat ed wit h in a shar ed net w or k bet w een t w o net w ork devices.

  Tw o t y pes of v ir t ual cir cu it s exist : sw it ched vir t ual cir cuit s ( SVCs) and per man en t v ir t ual cir cu it s ( PVCs) .

  • Table of Content s
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ndex SVCs ar e v ir t ual cir cu it s t hat ar e dy nam ically est ablished on d em and an d t er m inat ed w h en

  t r ansm ission is com p let e. Com m un icat ion ov er an SVC consist s of t hr ee phases: circuit est ablish ment , dat a t r ansfer , and cir cuit t erm inat ion . The est ablishm en t p hase inv olv es creat ing

  By Cisco Systems, Inc.

  t he vir t ual cir cuit b et ween t he sour ce and dest inat ion devices. Dat a t ran sf er inv olves t r ansm it t ing dat a bet w een t he d ev ices over t h e vir t ual cir cuit , an d t he circuit t erm inat ion p hase

  Pub lish er: Cisco Press

  inv olves t ear ing dow n t he v ir t ual cir cu it b et w een t h e sour ce and dest in at ion devices. SVCs ar e

  Pub Dat e: Sep tem ber 1 1, 2 003

  used in sit uat ions in w hich dat a t r ansmission b et ween devices is sp or adic, larg ely b ecause SVCs

  I SBN: 1- 58 705 -1 19 -2

  incr ease b andw idt h used due t o t he cir cuit est ablishm en t an d t er m inat ion phases, but t h ey

  Pages: 11 28 decrease t he cost associat ed w it h const ant vir t ual cir cuit availabilit y .

  PVC

  is a per m anent ly est ablish ed v irt u al circuit t hat consist s of one m ode: d at a t r ansf er . PVCs ar e used in sit uat ions in w hich dat a t r ansfer bet w een dev ices is const an t . PVCs d ecr ease t he ban dw idt h use associat ed w it h t h e est ab lish ment and t er min at ion of v ir t ual cir cu it s, but t hey incr ease cost s du e t o const an t v irt ual cir cu it av ailab ilit y . PVCs are generally conf igur ed b y t he The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ser v ice pr ovider w h en an or der is placed f or ser v ice. essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

WAN Dialup Services

  Dialup ser v ices of fer cost - effect iv e met h ods f or connect ivit y acr oss WANs. Tw o pop ular dialup im plem ent at ion s ar e dial- on- d em and r out in g ( D DR) and dial b ack up .

  Table of Content s •

DDR is a t echniqu e w hereby a r out er can dy nam ically init iat e a call on a sw it ch ed cir cu it w hen it

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ndex

  needs t o sen d d at a. I n a DD R set up, t he r out er is con figu red t o in it iat e t he call w hen cer t ain

  crit er ia ar e m et , such as a p art icular t yp e of net w ork t raf fic n eedin g t o be t ran sm it t ed. When t he connect ion is mad e, t r affic passes ov er t he line. Th e r out er config ur at ion specifies an idle t im er

  By Cisco Systems, Inc.

  t hat t ells t he r out er t o dr op t he con nect ion w hen t he cir cu it has rem ained id le for a cer t ain per iod.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Dial b ack up

  is anot her w ay of conf igur ing DDR. How ev er , in d ial back up, t he sw it ch ed cir cu it is

  I SBN: 1- 58 705 -1 19 -2

  used t o pr ov ide b ack up ser v ice for an ot her t y pe of cir cu it , such as point - t o- p oint or pack et

  Pages: 11 28

  sw it ch in g. Th e r out er is conf ig ur ed so t hat w h en a failur e is det ect ed on t he pr imar y cir cu it , t he dial b acku p line is in it iat ed . The d ial back up lin e t hen su ppor t s t he WAN con nect ion un t il t he pr im ary cir cuit is r est or ed . When t his occur s, t he d ial back up con nect ion is t er m in at ed.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

WAN Devices

  WANs u se n um erou s t y pes of devices t hat ar e specif ic t o WAN en vir onm ent s. WAN sw it ches, access ser v ers, m odem s, CSU/ DSUs, and I SD N t er min al adap t er s ar e d iscussed in t he f ollowin g sect ions. Ot her dev ices f ound in WAN env iron m en t s t hat ar e used in WAN im plem en t at ions

  Table of Content s • include rou t er s, ATM swit ches, and m ult iplex er s. I ndex •

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. WAN Switch

  Pub lish er: Cisco Press

  A WAN sw it ch is a m ult ipor t in t ern et w or k ing device used in car r ier n et w or k s. These devices

  Pub Dat e: Sep tem ber 1 1, 2 003

  t y pically sw it ch su ch t r af fic as Fr ame Relay , X. 25 , and SMD S, and oper at e at t he d at a link lay er

  I SBN: 1- 58 705 -1 19 -2

  of t he OSI r ef erence m odel. Figur e 3- 5 illust r at es t w o r out er s at r em ot e end s of a WAN t hat ar e

  Pages: 11 28 connect ed b y WAN sw it ches.

  

Figu r e 3 - 5 . Tw o Rout er s a t Re m ot e End s of a W AN Ca n Be Conn ect ed

by W A N Sw it che s

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

Access Server

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. An access ser v er act s as a concent r at ion point for d ial- in and d ial- ou t conn ect ions. Figur e 3- 6 illust rat es an access serv er concen t r at ing dial- out con nect ion s int o a WAN.

  

W AN

Table of Content s • I ndex •

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Modem

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom A m odem is a dev ice t hat in t er pr et s d ig it al and analog signals, enabling d at a t o be t r ansm it t ed nov ice t o ex pert . ov er voice- gr ade t elep hone lin es. At t he sour ce, digit al sig nals ar e conv er t ed t o a for m suit ab le for t r ansmission ov er analog comm u nicat ion f acilit ies. At t h e dest in at ion, t h ese an alog signals

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP ar e r et u r ned t o t heir dig it al for m . Figur e 3- 7 illust r at es a sim ple m odem - t o- m odem connect ion t hr ou gh a WAN.

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  

Figu r e 3 - 7 . A M od em Con ne ct i on Th r oug h a W A N Ha nd le s An al og a nd

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Di gi t al Sign a ls t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

CSU/DSU

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich A chann el ser vice unit / digit al ser vice unit ( CSU/ DSU) is a digit al- in t er f ace d ev ice used t o connect pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease a r ou t er t o a digit al cir cu it lik e a T1 . The CSU/ DSU also pr ovides sign al t im in g for com m unicat ion pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient bet w een t h ese dev ices. Figur e 3- 8 illust r at es t he placem ent of t he CSU/ DSU in a WAN decisions for t h eir net w ork s. im plem ent at ion .

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

ISDN Terminal Adapter

  An I SDN t er m inal ad apt er is a dev ice u sed t o con nect I SDN Basic Rat e I n t er f ace ( BRI ) connect ions t o ot her int er faces, such as EI A/ TI A- 2 32 on a r out er . A t er m inal ad apt er is essent ially an I SD N m odem , alt hou gh it is called a t er m inal ad apt er because it d oes not act u ally The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of conv er t analog t o d ig it al signals. Figur e 3- 9 illust r at es t he placem ent of t he t er min al adap t er in an I SDN env iron m en t . essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

  

Figu r e 3 - 9 . The Ter m i na l Ad apt er Con ne ct s t he I SD N Ter m i na l A da pt e r

t o Ot he r I nt er f a ce s

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1 :

  What ar e some t yp es of WAN circuit s?

  Table of Content s • 2 : I ndex

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  What is DD R, and h ow is it d iff er ent fr om dial backu p?

  3 :

  What is a CSU/ D SU used f or ? By Cisco Systems, Inc.

  4 :

  What is t h e diff er ence bet w een a m odem and an I SD N t er min al adap t er ?

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  For More Information • Mahler, Kev in. CCNA Tr ain ing Guide . I nd ianapolis: New Rid er s, 19 99.

  Table of Content s • • Cisco I OS Dial Solut ions. I nd ianapolis: Cisco Pr ess, 1 998 . I ndex •

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  • Cisco I OS Wid e Ar ea Net wor k in g Solut ions . I nd ianapolis: Cisco Pr ess, 1 999 .

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 4. Introduction to Cisco IOS Software

  • Table of Content s

  Obj e ct i ve s

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Under st and Cisco I OS sy st em ar chit ect ur e comp onent s.

  By Cisco Systems, Inc.

  Wor k w it h t he Cisco I OS Com m and Line I n t er f ace ( CLI ) an d com m on com m and s.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Lear n about Cisco I OS t r ou bleshoot in g t echn iq ues.

  I SBN: 1- 58 705 -1 19 -2 Under st and upg rad ing and r elease in for m at ion. Pages: 11 28

  The Cisco I OS soft w ar e is net w or k syst em soft war e t h at r un s on Cisco r out ers and swit ches. I t is used t o conf ig ur e, m onit or , and t r oub leshoot t he sy st em . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

System Architecture

  Lik e a com pu t er , a r out er has a CPU t hat var ies in p er f orm ance an d capab ilit ies depend ing on t he rou t er plat for m . Tw o ex am ples of pr ocessor s t hat Cisco uses are t he Mot orola 680 30 and t he Or ion/ R4600 . The Cisco I OS soft w ar e r un ning in t he r out er r equir es t he CPU or pr ocessor t o

  • Table of Content s

  m ake rou t ing and br idgin g d ecisions, m aint ain rou t ing t ables, and ot her sy st em m an agement

  I ndex • fu nct ions. The CPU m ust h ave access t o d at a in m em or y t o mak e d ecision s or t o get inst r uct ions.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Ther e ar e usually f our t y pes of m emor y on a Cisco rou t er : By Cisco Systems, Inc.

  Pub lish er: Cisco Press ROM

  — ROM is gener ally t he m emor y on a ch ip or m u lt ip le ch ips. I t is av ailable on a

  Pub Dat e: Sep tem ber 1 1, 2 003 r out er 's p rocessor boar d. I t is read- on ly, wh ich m eans t h at dat a cannot be wr it t en t o it .

  I SBN: 1- 58 705 -1 19 -2

  The in it ial sof t w ar e t hat r uns on a Cisco r out er is called t he boot st r ap soft w ar e an d is usually st or ed in ROM. The b oot st rap soft war e is in vok ed w h en t h e rou t er boot s u p. Pages: 11 28

  Fla sh

  — Flash mem or y is locat ed on a p rocessor b oar d SI MM bu t can be ex pand ed using PCMCI A ( r em ov able) car ds. Flash m emor y is m ost com m only u sed t o st or e one or m ore Cisco I OS sof t w are im ag es. Configu r at ion f iles or sy st em infor m at ion can also b e copied t o Flash . On some high- end sy st em s, Flash m em or y is also u sed t o h old b oot st rap soft war e.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  RAM

  — RAM is ver y fast mem or y t hat loses it s in for m at ion w h en t h e sy st em is r est ar t ed. I t is used in PCs t o st or e r unn ing applicat ions an d d at a. On a rou t er , RAM is u sed t o hold I OS syst em t ab les an d b uf fer s. RAM m em ory is basically used for all sy st em operat ion al st or age Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom r eq uir em ent s. nov ice t o ex pert .

  N V RA M

  — On t he r out er , NVRAM is used t o st or e t he st ar t u p conf igur at ion. This is t he New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP conf ig ur at ion file t hat I OS r eads w hen t he rou t er boot s u p. I t is ex t r emely f ast m em or y and is per sist ent across r eboot s. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Alt hou gh CPU and m emor y ar e r equir ed com pon en t s t o ru n I OS, a r out er m ust also hav e v arious Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . int er faces t o allow p ack et f or w ard in g. I nt er f aces ar e inp ut an d out pu t conn ect ions t o t h e rou t er t hat car ries dat a t hat needs t o be r out ed or sw it ch ed . The most com m on t y pes of int erf aces are

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Et h er n et and ser ial. Sim ilar t o t h e dr iver soft war e on a com p ut er w it h par allel p ort s and USB enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing por t s, I OS has dev ice dr iv er s t o sup por t t hese v ar ious int er face t y pes. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  All Cisco r out er s hav e a con sole p ort t h at pr ov ides an EI A/ TI A- 232 asyn chr onous ser ial Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, connect ion. Th e console por t can be conn ect ed t o a com p ut er' s serial conn ect ion t o gain t er m inal and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all access t o t he r out er . Most rou t ers also hav e an aux iliar y por t t hat is ver y similar t o t he con sole net w or kin g p rof essionals, r egar dless of ex pert ise. por t , b ut is t y pically u sed for mod em con nect ion f or r em ot e r out er m an agement .

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Ex am ple 4- 1 sh ows t he console out p ut of a new Cisco 3 640 r out er t h at h as ju st been st ar t ed. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Not ice t he p rocessor , int er f ace, an d m em ory in for m at ion t hat is list ed. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

Exa m pl e 4 - 1 . Cisco 3 6 4 0 Rout e r Console O u t pu t a t St ar t up

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1) Copyright (c) 1999 by Cisco Systems, Inc.

  Main memory is configured to 64 bit mode with parity disabled program load complete, entry point: 0x80008000, size: 0xa8d168

Self decompressing the image : #################################################

  • Table of Content s

  #################################################################### [OK]

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Restricted Rights Legend Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Use, duplication, or disclosure by the Government is

  Pages: 11 28 subject to restrictions as set forth in subparagraph (c) of the Commercial Computer Software - Restricted

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  Rights clause at FAR sec. 52.227-19 and subparagraph essent ial an d cu t t ing- edg e t ech nologies. (c) (1) (ii) of the Rights in Technical Data and Computer

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Software clause at DFARS sec. 252.227-7013. nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cisco Systems, Inc. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 170 West Tasman Drive Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat San Jose, California 95134-1706

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  Cisco Internetwork Operating System Software

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  IOS (tm) 3600 Software (C3640-IS-M), Version 12.2(10), RELEASE SOFTWARE (fc2)

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Copyright (c) 1986-2002 by Cisco Systems, Inc. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Compiled Mon 06-May-02 23:23 by pwade t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  Image text-base: 0x60008930, data-base: 0x610D2000

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  

cisco 3640 (R4700) processor (revision 0x00) with 94208K/4096K bytes of memory.

Processor board ID 17746964

  Bridging software.

  SuperLAT software (copyright 1990 by Meridian Technology Corp).

  5 Ethernet/IEEE 802.3 interface(s)

  • Table of Content s

  1 Serial network interface(s) I ndex •

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion DRAM configuration is 64 bits wide with parity disabled.

  By Cisco Systems, Inc.

  125K bytes of non-volatile configuration memory.

  Pub lish er: Cisco Press 8192K bytes of processor board System flash (Read/Write)

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 16384K bytes of processor board PCMCIA Slot0 flash (Read/Write)

  Pages: 11 28

  • System Configuration Dialog ---

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Would you like to enter the initial configuration dialog? [yes/no]:

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  When a n ew r out er is fir st st ar t ed, I OS r uns an aut oin st all pr ocess w her ein t h e user is pr om pt ed t o answ er a few q uest ion s. I OS t h en conf ig ur es t he sy st em based on t he in put pr ov id ed . Af t er Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age init ial set up, t he conf igur at ion is m ost com mon ly mod ified u sin g t he com man d- line int er face

  ( CLI ) . Ot h er w ay s of conf igur ing t he r ou t er in clu de HTTP and net w ork man agement app licat ions.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Cisco IOS CLI

  • Table of Content s
  • I ndex

  — This is t he fir st m ode a user has access t o aft er log ging int o t he r out er . The user m ode can be ident if ied by t he > pr omp t f ollowin g t he r out er nam e. Th is mod e allows t he user t o ex ecut e only t he b asic com m ands, su ch as t h ose t hat sh ow t he sy st em' s st at us. The sy st em can not be conf ig ur ed or rest ar t ed f rom t his m ode.

  Router>? Exec commands: access-enable Create a temporary Access-List entry access-profile Apply user-profile to interface clear Reset functions ...

  Not e t h at in t hese m odes, en t er ing t h e cont ext - sensit ive com m and ? at any point sh ow s t he av ailab le com m and s at t hat lev el. Th e ? can also be used in t he m idd le of a com man d t o show possible comp let ion opt ion s. Ex am ple 4- 2 sh ows t he u se of t h e ? com m and t o disp lay t he com man ds av ailable w it hin a giv en com m and m ode.

  — This m ode allow s users t o m odif y t he r u nning sy st em conf ig ur at ion. To en t er config ur at ion m ode, ent er t he com man d confi gur e t e rm in al f r om pr iv ileged m ode. Conf igur at ion m ode h as var ious su bm odes, st art in g w it h global conf ig ur at ion mod e, wh ich can be ident if ied by t he ( conf ig) # p rom p t f ollow ing t h e r out er nam e. As t h e config ur at ion m ode su bm odes chang e dependin g on w hat is being conf ig ur ed , t he wor d s insid e t he par en t heses chan ge. For exam ple, w hen y ou ent er in t er f ace conf ig ur at ion su bm ode, t he pr omp t chan ges t o ( con fig- if ) # f ollow ing t h e rou t er nam e. To exit configu r at ion m ode, t he user can ent er e nd or pr ess Ct r l- Z.

  Confi gur at i on m od e

  — This m ode allow s users t o v iew t he sy st em con figu rat ion , r est ar t t he syst em , and ent er conf igur at ion mod e. I t also allow s all t h e com m and s t hat ar e available in user m ode. Pr ivileged m od e can b e ident ified by t h e # pr om pt follow ing t he rou t er nam e. The u ser m od e e na ble com m and t ells I OS t hat t h e user w ant s t o en t er pr ivileged mod e. I f an en able passw or d or en able secr et passw ord h as been set , t he user need s t o ent er t he corr ect p assw or d or secr et t o b e gr ant ed access t o pr iv ileged m ode. An enable secret passw ord u ses st r onger encr yp t ion wh en it is st ored in t he conf ig ur at ion and, t herefor e, is safer . Pr ivileged m ode allow s t he user t o do an yt h ing on t he r out er , so it sh ould be u sed w it h cau t ion. To ex it pr iv ileg ed m ode, t h e user execut es t he di sa bl e com m and.

  P riv i le ge d m ode

  U se r m od e

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Cisco I OS h as t hr ee com man d m od es, each w it h access t o diff erent comm an d set s:

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

Exa m pl e 4 - 2 . Usi ng Con t e xt -Sen si t i ve H el p

  The f ollow in g st eps in t r oduce y ou t o t h e com m and s used t o chang e comm an d m ode, v iew syst em inf or mat ion , and conf ig ur e a p assw or d. Real CLI out pu t f r om a Cisco 3 640 r out er r un ning Cisco I OS sof t w are is sh ow n.

  St e p 1 .

  En t er en abled m ode by ent er in g e na ble an d pr essing Ent e r:

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Router> enable

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Router#

  Pages: 11 28 St e p 2 .

  To see w hich ver sion of I OS is ru nning on t he sy st em, en t er t he show v er sion com man d: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Router# show version Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Cisco Internetwork Operating System Software I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  IOS (tm) 3600 Software (C3640-IS-M), Version 12.2(10), RELEASE SOFTWARE (fc2)

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  Copyright (c) 1986-2002 by Cisco Systems, Inc.

  indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  Compiled Mon 06-May-02 23:23 by pwade

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  Image text-base: 0x60008930, data-base: 0x610D2000

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  ROM: System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  (fc1)

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Router uptime is 47 minutes System returned to ROM by reload

  

cisco 3640 (R4700) processor (revision 0x00) with 94208K/4096K bytes of memory.

Processor board ID 17746964 R4700 CPU at 100Mhz, Implementation 33, Rev 1.0

  • Table of Content s Bridging software.

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion X.25 software, Version 3.0.0.

  By Cisco Systems, Inc.

  SuperLAT software (copyright 1990 by Meridian Technology Corp).

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  5 Ethernet/IEEE 802.3 interface(s)

  I SBN: 1- 58 705 -1 19 -2

  1 Serial network interface(s) Pages: 11 28 DRAM configuration is 64 bits wide with parity disabled.

  125K bytes of non-volatile configuration memory.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  8192K bytes of processor board System flash (Read/Write) essent ial an d cu t t ing- edg e t ech nologies. 16384K bytes of processor board PCMCIA Slot0 flash (Read/Write)

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

  Configuration register is 0x2002

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  From t he ou t put , you can see t h at t his is a Cisco 3 640 r out er r un ning Cisco I OS sof t w are, Version 12. 2 ( 10) and t he sof t w are im ag e is locat ed on t he PCMCI A Flash car d in slot 0 .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing St e p 3 .

  Next , con figu re t he r out er n ame t o b e " I OS. " To en t er con figu rat ion m ode, u se t he t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing com man d confi gur e t e rm in al : indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  Router# configure terminal

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  Enter configuration commands, one per line. End with CNTL/Z.

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Router(config)# hostname IOS

  IOS(config)#

  Not ice t hat t he p rom p t chan ges t o " I OS" im mediat ely af t er you ent er t h e host na m e com m and. All conf ig ur at ion ch anges in Cisco I OS t ak e p lace im m ed iat ely .

  St e p 4 .

  Next , you need t o set t h e enable passw or d an d t he enable secret passw or d. The enable secr et p assw or d is st ored using st ron ger encry pt ion an d ov err ides t h e enable passw ord if it is con figur ed. To set bot h p assw or ds, y ou ent er t he f ollow ing :

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  IOS(config)# enable password cisco

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  IOS(config)# enable secret san-fran

  IOS(config)# exit

  IOS#

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. To g et int o enabled m od e, you need t o ent er t h e passwor d san - fr an . Th e e xi t com m and t ak es

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom y ou u p one level in t he con figu rat ion , or out of t he cu rr ent su bm ode. nov ice t o ex pert .

  St e p 5 .

  Aft er con figur ing t h e r out er nam e an d set t ing t he en able and enable secr et New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP passw ord s, you can ex am ine t h e r unn in g con figur at ion : Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  IOS# show running-config

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  Building configuration...

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Current configuration : 743 bytes t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy ! syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  version 12.2 pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. service timestamps debug uptime service timestamps log uptime

  ! hostname IOS ! enable secret 5 $1$IP7a$HClNetI.hpRdox84d.FYU.

  Table of Content s • enable password cisco

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion ! By Cisco Systems, Inc. ip subnet-zero

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 !

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 call rsvp-sync ! interface Ethernet0/0

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  no ip address essent ial an d cu t t ing- edg e t ech nologies. shutdown

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  half-duplex nov ice t o ex pert . !

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  interface Serial0/0 Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . no ip address I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat shutdown

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  no fair-queue indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  !

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  interface Ethernet2/0

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  no ip address

  har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  shutdown t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  half-duplex

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  !

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  interface Ethernet2/1 no ip address half-duplex ! interface Ethernet2/2 no ip address

  • Table of Content s

  shutdown I ndex •

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion half-duplex By Cisco Systems, Inc.

  ! Pub lish er: Cisco Press interface Ethernet2/3

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 no ip address

  Pages: 11 28 shutdown half-duplex

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  ! essent ial an d cu t t ing- edg e t ech nologies. ip classless

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  ip http server nov ice t o ex pert . ip pim bidir-enable

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  !

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  dial-peer cor custom Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ! I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

  line con 0

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  line aux 0

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all

  line vty 0 4 net w or kin g p rof essionals, r egar dless of ex pert ise.

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e ! har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions end t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease St e p 6 .

  The show r unni ng- confi g ou t pu t show s t h e config ur at ion t hat is cu rr ent ly act iv e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient in t he sy st em ; how ev er , t his conf igur at ion is lost if t he sy st em is rest ar t ed . To sav e t h is decisions for t h eir net w ork s. conf ig ur at ion t o NVRAM, you m ust issue t he follow ing com man d: IOS# copy running-config startup-config Destination filename [startup-config]? Building configuration... • Table of Content s

  I ndex • [OK] I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press

St e p 7 . To v iew t he st ar t u p con figur at ion saved in NVRAM, use t h e comm an d show

  Pub Dat e: Sep tem ber 1 1, 2 003 st ar t up- con fi g .

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  I n t he pr eced in g st ep seq uence, not ice t he Et her net an d serial in t erf aces t hat sh ow up in t he conf ig ur at ion file. Each in t er f ace requ ir es t h at cert ain par am et er s such as encapsulat ion and add ress be set b ef or e t he in t er f ace can be used pr oper ly. I n ad dit ion, I P rou t ing or br idg in g m ight need t o be conf igur ed. Ref er t o t he Cisco I OS in st allat ion and conf ig ur at ion guides av ailab le at w w w .cisco. com f or y our v er sion of soft w ar e t o lear n about all possible conf ig ur at ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of opt ion s and r ecom m en ded g uidelines. essent ial an d cu t t ing- edg e t ech nologies.

  Table 4 - 1 d escr ibes som e of t h e m or e com m on comm and s used t o m onit or t he syst em .

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  

Tab le 4 -1 . Com m a nd s Use d t o M on it or Ci sco I OS D ev ices

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Cisco I OS D e scri pt i on Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Com m a nd I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat show i nt e rf ace

  Display s cur rent st at us an d con figu rat ion det ails f or all int er faces in t he enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing syst em t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  

show pr ocesses Display s CPU u t ilizat ion and t h e cu rr ent pr ocesses ru nnin g in t he sy st em

indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . cpu

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all

  show bu ff er s

  Show s h ow syst em b uff ers ar e cur r ent ly allocat ed and f unct ioning f or net w or kin g p rof essionals, r egar dless of ex pert ise. pack et for w ar ding

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  

show m e m or y Show s h ow m emor y is allocat ed t o v arious sy st em fu nct ions an d m em ory

  har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ut ilizat ion a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  show di a g

  Display s det ails on har dw ar e card s in t he syst em t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  show i p r out e Display s t he cur r ent act iv e I P r out in g t able

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  show a rp

  Display s t he cur r ent act iv e I P ad dr ess- t o- MAC add ress m app in g in t h e pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient ARP t able decisions for t h eir net w ork s.

Debugging and Logging

  Cisco I OS sof t w are allow s f or det ailed d eb ugg in g for all p r ot ocols an d pr ocesses r un ning in t he syst em f or t r oubleshoot ing pu rp oses. Mor e inf or m at ion on debu ggin g can be ob t ained in t he Cisco I OS D eb ug Com m and Refer en ce, av ailable on w w w .cisco. com .

  • Table of Content s

  I ndex •

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. CAUTI ON

  Pub lish er: Cisco Press

  On ly Cisco I OS exp er t s sh ould enab le and disable de bug com m ands, b ecause t h ey can

  Pub Dat e: Sep tem ber 1 1, 2 003

  hav e a sev er e p er f orm ance im pact and sh ould be u sed w it h car e. I mp rop er use m ight

  I SBN: 1- 58 705 -1 19 -2

  leave t h e syst em inaccessible and in a f r ozen st at e in w hich n o pack et f orw ar din g t ak es

  Pages: 11 28 place.

  Sy st em m essag es are sh own on t he con sole an d can be enab led f or any session int o t he r out er . Dif ferent levels of sev erit y can be con figu red for diff er ent access m et h ods int o t he rou t er . Th e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of eight m essage sever it y lev els are as follow s: essent ial an d cu t t ing- edg e t ech nologies.

  Em er ge ncy ( se v er it y 0 )

  — The syst em is u nusable Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

  Al er t ( se ve ri t y 1 )

  — I m m ediat e act ion is need ed New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  Crit ical ( se ve ri t y 2 )

  — Cr it ical con dit ion Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Err or ( se v er it y 3 )

  — Er ror con dit ion Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  W ar ni ng ( se v er it y 4 )

  — Warn ing con dit ion

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat N ot i fi ca t i on ( se ve ri t y 5 )

  — Norm al b ut sig nificant con dit ion enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  I nf orm a t iona l ( sev e rit y 6 )

  — I n for m at ional m essag e indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  D e bugg ing ( se ve ri t y 7 )

  — Debugg ing m essage and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. The log gin g com m and dir ect s t he out put t o v ar ious t er m in als at t ached t o t h e sy st em or v irt ually connect ed, such as Teln et sessions. Ex am ple 4- 3 sh ows how t h e log gin g com m and can b e used Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e t o det er m ine t h e sev erit y lev el of t he m essag es show n . har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

Exa m pl e 4 - 3 . log gin g Com m an d

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient

  IOS(config)# logging ? decisions for t h eir net w ork s. Hostname or A.B.C.D IP address of the logging host buffered Set buffered logging parameters exception Limit size of exception flush output facility Facility parameter for syslog messages history Configure syslog history table host Set syslog server host name or IP address

  Table of Content s • I ndex • monitor Set terminal line (monitor) logging level I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By on Enable logging to all supported destinations Cisco Systems, Inc. rate-limit Set messages per second limit

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 source-interface Specify interface for source address in logging

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 transactions trap Set syslog server logging level

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  IOS(config)#

  essent ial an d cu t t ing- edg e t ech nologies. logging console ?

  <0-7> Logging severity level

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

  alerts Immediate action needed (severity=1)

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  critical Critical conditions (severity=2)

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  debugging Debugging messages (severity=7) Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . emergencies System is unusable (severity=0) I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat errors Error conditions (severity=3)

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  guaranteed Guarantee console messages indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  informational Informational messages (severity=6)

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  notifications Normal but significant conditions (severity=5)

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  warnings Warning conditions (severity=4)

  har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  <cr> t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient En abling a h ig her lev el of m essages show s all low er - lev el m essages as w ell. The d eb ugg in g decisions for t h eir net w ork s. level, or level 7 , show s all m essag es. Sy st em messages m ay also be b uff ered and seen using t he

  show l oggi ng

  com m and in pr iv ileged m ode. A user m ay also sen d logg ing m essages t o a syslog ser v er using t he log gin g host com m and in con figu rat ion m ode. A sy slog ser ver can be not r est r ict ed by t he am oun t of m emor y on t h e r out er.

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Reloading and Upgrading

  A sy st em rest ar t on Cisco r out er s is called a r eload. I f t he rou t er need s t o be r eload ed f or any r eason, t he re l oa d com m and needs t o be ent er ed f rom pr ivileged mod e, as show n in Ex am ple 4-

  4 . Th e re l oa d com m and also allow s a t im e t o be set so t hat t he syst em r est art s aft er t h e

  • Table of Content s specif ied t im e exp ires.

  I ndex •

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. Exa m pl e 4 - 4 . Sy st em Re load O pt i ons

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  IOS# reload ?

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 LINE Reason for reload at Reload at a specific time/date cancel Cancel pending reload

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  in Reload after a time interval <cr>

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The sy st em can also b e reloaded by sw it ching it of f and t hen back on again. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age The con figur at ion r eg ist er is u sed t o sp ecify t he r out er 's b eh avior d ur ing t he r eloading pr ocess. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I t d et er m ines w het her t he I OS im age shou ld be load ed , det er min es w h et h er t erm inal access par am et er s ar e p rov ided, an d en ables or disables t he Esc key . The conf igur at ion r eg ist er can be

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat m odified in conf igur at ion m ode u sing t h e confi g- re gist e r com m and.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all

CAUTI ON net w or kin g p rof essionals, r egar dless of ex pert ise

  Use t he confi g- re gist e r com m and only if y ou com plet ely und er st and it s eff ect s. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e I ncor rect u se of t his comm an d can m ake t he sy st em in accessible. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy By def ault , t h e r out er fir st t r ies t o b oot f r om t he fir st im age in t he on boar d sy st em Flash, if syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich av ailab le, an d t hen it t r ies t he PCMCI A Flash car ds. The u ser m ay also specify w h ich im ages or pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease locat ions t o at t emp t b oot ing fr om an d t h e or der using t he boot sy st em com m and in pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient conf ig ur at ion mod e: decisions for t h eir net w ork s.

  IOS(config)# boot system slot0

  • Table of Content s

  This causes t he sy st em t o at t em pt boot in g f r om an imag e in t he Flash m emor y in PCMCI A slot 0

  I ndex • befor e g oing t o t h e onb oard syst em Flash.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  To u pgr ad e t he Cisco I OS sof t w ar e v er sion r un ning on a r out er , y ou m ust f ir st det er m ine t h e r ight imag e t o upg rad e t o u sin g t h e up gr ade plan ners available on w w w .cisco. com .

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

CAUTI ON

  At t em pt ing t o load an incor r ect im age for y our sy st em m ig ht leav e t he sy st em inaccessible. Ensur e t h at y ou hav e t he cor r ect soft w ar e im age and m eet t he RAM an d Flash m emor y r equir ement s t o r un an d st or e t h e imag e befor e inst alling. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  The copy com m and copies an im age in t o Flash m em ory . Th er e ar e m any way s t o do t his, as Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom dem onst r at ed in Ex am ple 4- 5 . nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Exa m pl e 4 - 5 . Opt ion s for Copy in g an I OS I m a ge in t o Fla sh M em or y

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  IOS# copy ? I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat /erase Erase destination file system.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  flash: Copy from flash: file system indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  ftp: Copy from ftp: file system

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  null: Copy from null: file system

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  

nvram: Copy from nvram: file system har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on

  a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . pram: Copy from pram: file system Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich rcp: Copy from rcp: file system pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  running-config Copy from current system configuration pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. slot0: Copy from slot0: file system slot1: Copy from slot1: file system system: Copy from system: file system tftp: Copy from tftp: file system xmodem: Copy from xmodem: file system ymodem: Copy from ymodem: file system

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  The m ost com m on m et h ods ar e TFTP an d FTP. Af t er t he f ile has b een placed on y our TFTP or FTP ser v er, en t er t he copy com m and fr om p r iv ileg ed m ode an d answ er t he qu est ions on ser ver I P

  Pub lish er: Cisco Press

  add ress and sour ce and dest inat ion filenam es. Af t er you specify w hich imag e t he sy st em sh ould

  Pub Dat e: Sep tem ber 1 1, 2 003

  load using t he boot sy st em com m and, a re l oa d is requ ir ed for t he new v ersion of I OS t o be

  I SBN: 1- 58 705 -1 19 -2 boot ed. Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary

  This chap t er int r oduced t he f und ament als of Cisco I OS soft w ar e, t he operat in g sy st em t hat ru ns on Cisco r out ers and swit ches. Cisco I OS sof t w ar e ru ns on a CPU and r eq uir es sev er al t yp es of m em or y t o st ore t he im age, conf ig ur at ion, r un ning app licat ions, an d dat a. Th e CLI is t he m ost

  Table of Content s •

  com mon m et hod used t o config ur e, mon it or , and t r oubleshoot a syst em r un ning Cisco I OS

  I ndex •

  soft w ar e. The sof t w are pr ovides com pr ehensiv e d eb ugg in g and logging capabilit ies. You can

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  up gr ade t h e soft w ar e im age by dow nloading it usin g one of m any op t ions and t h en f ollow ing a By ser ies of sim p le st eps. Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1 :

  What ar e t he four main m emor y t y pes in a r out er ?

  Table of Content s • 2 : I ndex

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  What ar e t he t hr ee Cisco I OS com man d mod es?

  3 :

  What is t h e pr ocess of r est ar t ing a Cisco I OS sy st em called ? By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information

  • Cisco I OS soft w ar e Release 1 2. 2 docum ent at ion: w w w .cisco. com / pcgi- bin/ Suppor t / b r owse/ psp_ view .p l?p= Soft w ar e: I OS: 12. 2 &s= Docum ent at ion .

  Table of Content s • I ndex •

  • Cisco I OS Conf igu r at ion Fund am ent als , Cisco Pr ess, 1 997 , I SBN 06 410 491 29.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  • Cisco I OS in a Nut shell , O'Reilly & Associat es, I n c. , 2 001 , I SBN 15 659 294 2X.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  • I n side Cisco I OS Sof t w ar e Archit ect ur e, Pear son Educat ion, 2 000 , I SBN 15 787 018 13.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  • Table of Content s Lear n about diff erent LAN pr ot ocols.
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Lear n about t he d iff er ent met h ods used t o deal w it h m edia cont ent ion .

  By Cisco Systems, Inc.

  Lear n about diff erent LAN t opologies.

  Pub lish er: Cisco Press

  This chap t er int r oduces t he t echn ologies em ploy ed in dev ices loosely r efer r ed t o as br idges an d

  Pub Dat e: Sep tem ber 1 1, 2 003

  sw it ch es. Top ics sum m ar ized her e include general lin k layer d ev ice operat ion s, local and rem ot e

  I SBN: 1- 58 705 -1 19 -2

  br idg in g, ATM sw it ch in g, an d LAN sw it ch ing. Chapt er s in Par t V , " Br idg in g and Swit chin g, "

  Pages: 11 28 add ress specif ic t ech nologies in m or e d et ail.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Are Bridges and Switches?

  Br id ges

  an d sw it ches ar e d at a com m unicat ions d ev ices t hat op er at e pr in cip ally at Lay er 2 of t he OSI r efer en ce mod el. As su ch, t h ey ar e w idely r ef err ed t o as d at a link lay er dev ices.

  • Table of Content s

  Br idges becam e com m er cially av ailab le in t h e early 1 980 s. At t h e t ime of t heir int r oduct ion,

  I ndex

  br idg es conn ect ed and enabled packet for w ard ing bet w een hom ogeneous net w ork s. Mor e

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion r ecent ly , br idg in g bet w een diff erent net w or ks has also been defined and st andar dized.

  By Cisco Systems, Inc.

  Sever al k inds of b rid ging hav e pr ov en im por t ant as int er net w or kin g d ev ices. Tr anspar ent

  br idgin g

  is foun d p r im ar ily in Et her net env iron m en t s, w hile sour ce- r out e br id ging occur s

  Pub lish er: Cisco Press

  pr im arily in Tok en Rin g env ir onm en t s. Tr anslat ional b ridging p r ovides t r anslat ion bet w een t he

  Pub Dat e: Sep tem ber 1 1, 2 003 for m at s an d t ran sit pr inciples of diff er ent m ed ia t y pes ( usually Et hern et and Tok en Rin g) .

  I SBN: 1- 58 705 -1 19 -2

  Finally, sour ce- r out e t r anspar en t b ridging com bines t h e algor it hm s of t r anspar ent br idging an d

  Pages: 11 28 sour ce- r out e br idging t o en able com mu nicat ion in m ixed Et h er net / Tok en Rin g en vir onm ent s.

  Today , sw it ching t ech nology h as emer ged as t he ev olut ionar y heir t o br idging - based int er net w ork ing solut ions. Sw it ching im plement at ion s now dom inat e ap plicat ion s in w h ich br idg in g t echn ologies wer e im plement ed in pr ior net w ork desig ns. Super ior t hr oug hpu t per for m ance, high er por t d en sit y , low er per - por t cost , and g reat er f lex ibilit y hav e cont r ibut ed t o The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he em er gence of sw it ches as r eplacem ent t ech nology f or br idg es an d as com p lem ent s t o r out ing essent ial an d cu t t ing- edg e t ech nologies. t echnology .

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Link Layer Device Overview

  Br idging and sw it ching occu r at t he link lay er , w h ich cont r ols dat a flow , h andles t r ansm ission err or s, pr ov ides phy sical ( as opp osed t o log ical) addr essing , and m anages access t o t he p hy sical m ed ium . Br idges pr ov ide t h ese f unct ions by using v ariou s lin k layer p rot ocols t h at d ict at e

  • Table of Content s

  specif ic flow con t rol, er r or han dling, addr essing , and m ed ia- access algor it hm s. Ex amp les of

  I ndex • pop ular link lay er pr ot ocols in clu de Et hern et , Token Ring , and FDDI .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Br idges and sw it ch es are not com plicat ed d ev ices. Th ey an alyze in com ing f ram es, m ake By Cisco Systems, Inc. for w ar ding decision s based on inf or mat ion cont ained in t he f ram es, and for w ar d t he f ram es t ow ar d t he dest inat ion. I n som e cases, such as sour ce- r out e b r id ging , t he ent ir e p at h t o t h e

  Pub lish er: Cisco Press

  dest inat ion is cont ained in each f r ame. I n ot her cases, su ch as t r anspar ent br idgin g, f ram es ar e

  Pub Dat e: Sep tem ber 1 1, 2 003 for w ar ded one hop at a t im e t ow ar d t he d est inat ion .

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Upper - layer p rot ocol t ran sp arency is a pr im ary ad van t age of b ot h br idging and sw it ching. Becau se bot h device t y pes op er at e at t he link lay er , t hey ar e not r eq uir ed t o ex am ine u pper - lay er in for m at ion. Th is means t hat t hey can r apid ly for w ar d t r af fic r epr esent ing an y net w ork lay er p r ot ocol. I t is not uncom m on for a br idge t o m ov e AppleTalk, DECn et , TCP/ I P, XNS, an d ot her t r af fic b et w een t wo or m or e net w or ks.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Br idges ar e capable of f ilt er ing fr am es based on an y Lay er 2 f ield s. For ex am ple, a b rid ge can be essent ial an d cu t t ing- edg e t ech nologies. pr ogr am m ed t o r ej ect ( not for w ar d) all fr am es sou rced fr om a par t icu lar net w or k. Because link lay er in for m at ion of t en in clu des a r efer en ce t o an upp er - lay er pr ot ocol, br idges u su ally can filt er on t his p aram et er. Fu rt herm or e, filt er s can b e helpfu l in dealin g w it h un necessary br oadcast and

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom m ult icast pack et s. nov ice t o ex pert .

  By div iding lar ge net w or k s int o self- cont ain ed un it s, br idges an d sw it ches pr ov id e sev eral New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP adv ant ag es. Because only a cer t ain percent ag e of t r aff ic is for w ar ded, a br idge or sw it ch dim inishes t he t raf fic ex perienced by dev ices on all connect ed segm ent s. The br id ge or sw it ch

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age w ill act as a fir ew all for som e pot en t ially d amag ing net w ork er r or s and w ill accom m odat e com mu nicat ion b et w een a lar ger num b er of d ev ices t han w ould be supp or t ed on any sing le LAN Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . connect ed t o t he br id ge. Br idges and sw it ches ex t end t he ef fect ive leng t h of a LAN, perm it t ing

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat t he at t achm en t of d ist an t st at ions t hat was not pr ev iously per mit t ed.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Alt hou gh br idges and sw it ches sh ar e most r elevan t at t rib ut es, sev er al d ist in ct ion s diff erent iat e t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . t hese t echnologies. Br id ges ar e gener ally u sed t o segm ent a LAN int o a couple of sm aller seg m en t s. Swit ches ar e g en er ally used t o seg m en t a lar g e LAN in t o m any sm aller segm ent s. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Br idges gener ally hav e only a few por t s for LAN connect ivit y , w h er eas swit ches g en er ally hav e and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. m any . Sm all sw it ch es su ch as t h e Cisco Cat aly st 29 24XL h ave 2 4 p or t s capable of cr eat in g 2 4 dif fer en t net w or k seg m en t s for a LAN. Lar ger sw it ch es su ch as t h e Cisco Cat aly st 65 00 can h ave Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e hu ndr eds of p ort s. Sw it ches can also be used t o conn ect LANs w it h diff erent m ed ia—for ex am ple, har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a 1 0- Mb ps Et hern et LAN and a 1 00- Mbps Et her net LAN can b e connect ed u sin g a swit ch. Some a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions sw it ch es su ppor t cu t - t hr oug h sw it ching, w hich r educes lat ency and delays in t h e net w or k, w hile t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . br idg es sup por t on ly st ore- and - for w ar d t raf fic sw it ching . Fin ally , sw it ches r ed uce collisions on Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy net w or k seg ment s becau se t hey pr ov ide dedicat ed bandw id t h t o each n et w or k segm en t . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Types of Bridges

  Br idges can be gr oup ed int o cat egor ies b ased on var ious p r oduct ch aract er ist ics. Using one pop ular classificat ion schem e, br idges ar e eit her local or r emot e. Local br idges p r ovide a dir ect connect ion bet w een mu lt iple LAN segm ent s in t h e sam e ar ea. Rem ot e br idges con nect m ult iple

  • Table of Content s

  LAN segm ent s in d if fer en t ar eas, usually ov er t elecomm u nicat ion s lines. Figur e 5- 1 illust r at es

  • I ndex t hese t w o con figur at ion s.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 5 - 1 . Loca l a n d R em ot e B r idge s Con ne ct LA N Se gm e nt s i n

Pub lish er: Cisco Press

  

Specif ic Ar e as

Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Rem ot e br idg in g pr esent s sever al u nique in t er n et w or k in g ch alleng es, on e of w hich is t h e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . dif fer en ce b et ween LAN an d W AN speed s. Alt houg h sever al f ast WAN t echn olog ies n ow ar e est ablish in g a pr esence in geogr aph ically disper sed int er net w ork s, LAN speed s ar e oft en m uch

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  fast er t h an W AN speed s. Vast dif fer en ces in LAN an d WAN speed s can pr ev ent user s f rom enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing r unn ing delay- sensit ive LAN app licat ions over t h e WAN. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Rem ot e br idg es can not im pr ov e WAN sp eeds, b ut t hey can com pensat e f or speed discrepan cies Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, t hr ou gh a suf ficien t bu ff er ing capabilit y . I f a LAN dev ice capab le of a 3 - Mbps t r ansmission r at e and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all w ant s t o com mu nicat e w it h a dev ice on a rem ot e LAN, t he local b ridg e m ust r egulat e t he 3 - Mbps net w or kin g p rof essionals, r egar dless of ex pert ise. dat a st r eam so t hat it does n ot ov erw h elm t he 64 - kb ps serial lin k. This is don e by st or ing t he incom ing dat a in on boar d b uf fers and send ing it ov er t he ser ial lin k at a r at e t hat t he ser ial link Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e can accom m odat e. This b uff erin g can be achiev ed only f or shor t b ur st s of dat a t hat do not har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ov er w helm t h e br idge's buf fer ing cap abilit y. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  The I n st it u t e of Elect rical an d Elect r onic En gineers ( I EEE) dif fer en t iat es t he OSI lin k layer int o Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy t w o separ at e sub lay er s: t he Media Access Con t r ol ( MAC) su blayer an d t he Logical Lin k Con t rol syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

  ( LLC) su blayer . The MAC su blayer p er m it s and or chest r at es m edia access, such as cont ent ion

  pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease and t ok en p assing , w hile t he LLC sublay er deals w it h fr am in g, f low cont r ol, err or con t rol, and pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient MAC sublay er addr essing . decisions for t h eir net w ork s.

  Som e br idges ar e MAC- layer b ridges, w hich br idge bet w een hom ogeneous n et w or k s ( f or exam ple, I EEE 8 02. 3 and I EEE 8 02. 3) , w hile ot her b ridg es can t r anslat e b et w een d iffer ent lin k lay er p r ot ocols ( f or ex amp le, I EEE 802 .3 an d I EEE 802 .5 ) . The b asic mechanics of such a

  

Figu r e 5 - 2 . A M AC-Lay er Br idg e Con ne ct s t he I EEE 8 0 2 . 3 a nd I EEE

8 0 2 .5 N et w or k s

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  

Figur e 5- 2 illust r at es an I EEE 80 2. 3 h ost ( Host A) for m ulat ing a packet t hat con t ains ap plicat ion

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all inf orm at ion and encapsulat ing t h e packet in an I EEE 8 02. 3- com pat ib le fr am e for t ran sit ov er t he net w or kin g p rof essionals, r egar dless of ex pert ise.

  I EEE 8 02. 3 m ed iu m t o t he b ridg e. At t h e br idge, t he fr am e is st r ipped of it s I EEE 80 2. 3 header at t he MAC sublay er of t he link lay er and is sub sequ en t ly passed up t o t he LLC sublay er for Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e fu r t her pr ocessing. Aft er t h is pr ocessin g, t h e pack et is passed back d ow n t o an I EEE 80 2. 5 har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on im plem ent at ion , w hich en cap su lat es t he pack et in an I EEE 802 .5 h ead er f or t r ansm ission on t he a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions I EEE 8 02. 5 net w or k t o t h e I EEE 80 2. 5 host ( Host B) . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy A b r id ge's t ran slat ion bet w een net w or k s of diff er ent t y pes is nev er p er f ect becau se one net w or k syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich likely w ill supp ort cer t ain fr am e f ields an d pr ot ocol fu nct ions not supp ort ed by t he ot h er pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease net w or k. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Types of Switches

  Sw it ch es

  ar e d at a link lay er dev ices t hat , like b rid ges, en able m ult iple p hy sical LAN seg ment s t o be in t er conn ect ed in t o a sin gle lar ger net w or k. Sim ilar t o br idges, sw it ch es f or w ard and f lood t r aff ic based on MAC add r esses. An y net w or k device w ill creat e som e lat ency. Sw it ch es can use

  Table of Content s •

  dif fer en t f orw ar din g t echniq ues—t wo of t hese ar e st ore- an d- for w ar d sw it ching and cut - t hr ough

  I ndex • sw it ch in g.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I n st or e- an d- f orw ar d sw it ching , an ent ir e fr am e m ust be r eceived befor e it is for w ar ded. Th is By Cisco Systems, Inc. m ean s t hat t he lat en cy t hr ough t h e sw it ch is r elat iv e t o t he f ram e size—t he lar ger t h e fr am e size, t he long er t he delay t h rou gh t he sw it ch. Cu t - t hr ough sw it ching allow s t h e swit ch t o begin

  Pub lish er: Cisco Press

  for w ar ding t h e fr am e w hen en ough of t he fr am e is r eceived t o m ak e a f or w ard in g decision. Th is

  Pub Dat e: Sep tem ber 1 1, 2 003

  r ed uces t he lat ency t h rou gh t he sw it ch. St or e- and- for w ard sw it ching giv es t he sw it ch t h e

  I SBN: 1- 58 705 -1 19 -2

  opp ort unit y t o evaluat e t he f r ame f or er ror s b ef or e for w ar ding it . This cap abilit y t o n ot f orw ar d

  Pages: 11 28

  fr am es cont aining er ror s is on e of t he ad van t ages of sw it ch es over hu bs. Cu t - t hr oug h sw it ching does n ot of fer t his ad van t age, so t he sw it ch m ight for w ar d fr am es con t aining err or s. Many t yp es of sw it ch es ex ist , inclu ding ATM sw it ches, LAN sw it ches, and v ar iou s t y pes of WAN sw it ches.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  ATM Switch essent ial an d cu t t ing- edg e t ech nologies.

  Asyn ch ron ous Tr ansf er Mode ( ATM) sw it ches p r ovide high- speed sw it ching an d scalable

  ban dw idt hs in t h e w or kg rou p, t h e en t erp rise net w or k back bone, an d t he w ide ar ea. ATM Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom sw it ch es su ppor t voice, vid eo, and dat a applicat ions, and ar e desig ned t o sw it ch f ixed- size nov ice t o ex pert . inf orm at ion un it s called cells, w hich ar e u sed in ATM com mu nicat ion s. Figur e 5- 3 illust r at es an ent er pr ise n et w or k com pr ised of m ult iple LANs in t erconn ect ed acr oss an ATM b ackb one.

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  

Figu r e 5 - 3 . M ul t i- LA N Ne t w or k s Ca n Use a n ATM - Ba se d B ack b on e W he n

Sw i t ch in g Cel ls

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

LAN Switch

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  

LAN sw it ches ar e u sed t o in t er conn ect mu lt iple LAN segm ent s. LAN sw it ch in g p r ovides d ed icat ed,

  collision- f ree com m unicat ion bet w een net w ork devices, wit h sup por t f or m ult iple sim ult aneous Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age conv er sat ions. LAN swit ches ar e d esigned t o sw it ch dat a fr am es at hig h speeds. Figur e 5- 4 illust rat es a sim p le net w ork in w hich a LAN sw it ch int er con nect s a 1 0- Mb ps and a 100 - Mbp s Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  Et h er n et LAN.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  

Figu r e 5 - 4 . A LAN Sw i t ch Can Lin k 1 0 - M bps a nd 1 0 0 - M bp s Et he r ne t

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

Segm e nt s

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Review Questions 1 : What lay er of t he OSI r efer ence m odel t o b r id ges and sw it ch es op er at e.

  Table of Content s • 2 : I ndex

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  What is cont r olled at t he link lay er?

  3 :

  Under one popu lar classificat ion schem e w hat are b r id ges classified as? By Cisco Systems, Inc.

  4 :

  What is a sw it ch?

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

For More Information

  • Cisco' s w eb sit e ( w w w .cisco. com ) is a w ond er f ul sour ce for mor e inf or mat ion ab out t hese t opics. The D ocu m en t at ion sect ion includ es in - dept h discussion s on man y of t he t opics cov
  • Table of Content s in t his chapt er .
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  • Clark , Kenn ed y, and Kev in Hamilt on . Cisco LAN Sw it chin g . I nd ianapolis: Cisco Pr ess, Au gust By Cisco Systems, Inc. 19 99.

  Pub lish er: Cisco Press

  • Cisco Syst em s, I n c. Cisco I OS Br idging and I BM Net w ork Solut ions . I nd ianapolis: Cisco Pr ess, Pub Dat e: Sep tem ber 1 1, 2 003 Jun e 19 98.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 6. Routing Basics Obj e ct i ve s

  • Table of Content s Lear n t he b asics of r out ing pr ot ocols.
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Lear n t he d if fer en ces b et w een lin k- st at e an d dist ance vect or r out in g p rot ocols.

  By Cisco Systems, Inc.

  Lear n about t he m et r ics used by rou t ing pr ot ocols t o d et er m in e pat h select ion.

  Pub lish er: Cisco Press

  Lear n t he b asics of how dat a t rav els fr om end st at ions t hr ough int er m ed iat e st at ions and

  Pub Dat e: Sep tem ber 1 1, 2 003 on t o t he dest inat ion en d st at ion .

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Under st and t he d if fer en ce bet w een r out ed pr ot ocols an d rou t ing pr ot ocols. This chap t er int r oduces t he und er ly in g con cept s wid ely u sed in r ou t ing pr ot ocols. Top ics sum m arized her e inclu de r out in g p rot ocol com pon en t s and algor it hm s. I n addit ion , t he r ole of r out ing pr ot ocols is br iefly cont r ast ed w it h t h e role of r ou t ed or n et w or k p rot ocols. Sub sequ en t chapt er s in Par t VI I , " Rout ing Pr ot ocols, " addr ess sp ecific r out in g pr ot ocols in m or e det ail, w hile The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he net w ork pr ot ocols t hat use rou t ing pr ot ocols ar e discu ssed in Par t VI , " Net w or k Pr ot ocols. " essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is Routing?

  Rou t in g is t he act of m ov ing infor m at ion across an int er net w ork fr om a sou rce t o a d est inat ion .

  Along t he way , at least one int er m ed iat e nod e t y pically is encoun t er ed. Rout ing is of t en cont r ast ed w it h br idgin g, w hich m ig ht seem t o accom plish p recisely t h e sam e t h ing t o t h e casu al

  • Table of Content s

  observ er . The p rim ar y dif fer en ce b et ween t he t w o is t hat br idging occur s at Lay er 2 ( t he link

  I ndex •

  lay er ) of t he OSI refer ence m odel, w hereas r out in g occur s at Lay er 3 ( t he net w or k lay er ) . Th is

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  dist inct ion pr ovid es r ou t in g and br idging w it h dif ferent inf orm at ion t o use in t he pr ocess of By m ovin g in for m at ion f r om sour ce t o d est inat ion, so t he t w o f unct ions accom plish t h eir t ask s in Cisco Systems, Inc. dif fer en t w ay s.

  Pub lish er: Cisco Press

  The t opic of r out ing has been cover ed in com put er scien ce lit er at ur e for m ore t han t w o decades,

  Pub Dat e: Sep tem ber 1 1, 2 003

  bu t r out in g achiev ed com mer cial popu larit y as lat e as t he mid - 198 0s. The p rim ar y r eason for

  I SBN: 1- 58 705 -1 19 -2

  t his t im e lag is t h at net w or k s in t he 19 70s w er e simp le, h om ogeneous env iron ment s. Only

  Pages: 11 28 r elat iv ely recen t ly has lar ge- scale in t er n et w or k ing becom e p opular .

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Routing Components

  Rou t ing inv olv es t w o b asic act iv it ies: det er m ining opt im al r ou t ing pat hs and t r anspor t ing inf orm at ion gr oup s ( t y pically called p ack et s) t h rou gh an in t ern et w or k . I n t he cont ex t of t h e r out ing pr ocess, t h e lat t er of t hese is r ef err ed t o as p ack et sw it ching. Alt houg h p ack et sw it ching

  • Table of Content s is r elat iv ely st r aigh t for w ar d, p at h det er m inat ion can b e v er y com plex .
  • I ndex

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. Path Determination

  Pub lish er: Cisco Press

  Rou t ing pr ot ocols use m et r ics t o ev aluat e w h at pat h w ill b e t he b est for a pack et t o t rav el. A

  Pub Dat e: Sep tem ber 1 1, 2 003

  m et ric is a st andar d of m easur em en t , such as pat h ban dw idt h , t hat is used b y r out ing

  I SBN: 1- 58 705 -1 19 -2

  algor it hm s t o det erm ine t he opt im al p at h t o a dest in at ion. To aid t he pr ocess of p at h

  Pages: 11 28

  det er min at ion , r out ing algor it hm s in it ialize an d m aint ain r out ing t ab les, w hich cont ain rou t e inf orm at ion. Rout e in for m at ion var ies dependin g on t h e r out ing algor it hm u sed. Rou t ing algor it hm s fill r out in g t ables w it h a var iet y of inf orm at ion. Dest in at ion/ nex t h op associat ions t ell a r out er t hat a par t icu lar dest in at ion can be r eached op t im ally b y sen ding t he pack et t o a par t icular r out er r epr esent in g t h e " nex t h op" on t h e w ay t o t he f in al dest inat ion. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of When a r out er receiv es an in com ing p ack et , it check s t he d est inat ion add r ess and at t em pt s t o essent ial an d cu t t ing- edg e t ech nologies. associat e t h is addr ess w it h a nex t hop . Figur e 6- 1 d ep ict s a sam ple dest inat ion/ n ex t hop r out ing t able.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

  

Figu r e 6 - 1 . De st in at i on/ N ex t Hop Associ at ion s De t e r m i ne t he D at a' s

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  

O pt i m al Pa t h

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Rou t ing t ables also can cont ain ot h er in for m at ion, such as dat a abou t t h e desir abilit y of a pat h. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Rou t er s com par e m et rics t o det erm ine opt im al r out es, and t hese m et rics dif fer depend ing on t he pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease design of t he r out in g alg orit h m used. A var iet y of comm on m et rics w ill be in t rod uced an d pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient descr ibed lat er in t h is chapt er . decisions for t h eir net w ork s. Rou t er s com m unicat e w it h one an ot her and m aint ain t heir r out ing t ab les t h r ough t he t r ansm ission of a v ar iet y of m essag es. Th e rou t ing upd at e m essage is one such messag e t hat gener ally con sist s of all or a por t ion of a r out in g t able. By analy zing rou t ing up dat es fr om all st at e of t h e send er ' s link s. Link inf or mat ion also can be u sed t o b uild a comp let e pict ur e of net w or k t opolog y t o enab le rou t er s t o det er min e opt im al r out es t o net w or k dest in at ions.

Switching

  Sw it ching algor it hm s is r elat iv ely sim ple; it is t he sam e f or m ost r out ing pr ot ocols. I n m ost

  • Table of Content s

  cases, a host d et er m in es t hat it m ust send a packet t o anot her host . Hav ing acquir ed a r out er' s

  • I ndex

  add ress by som e m eans, t he sou rce h ost sen ds a packet addr essed sp ecifically t o a r out er' s

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  ph ysical ( Media Access Cont r ol [ MAC] - lay er ) addr ess, t h is t im e w it h t h e pr ot ocol ( n et w or k lay er ) By add ress of t he dest in at ion h ost . Cisco Systems, Inc. As it ex am ines t he p ack et 's dest in at ion p rot ocol addr ess, t he r out er det er m in es t hat it eit her

  Pub lish er: Cisco Press

  k now s or d oes not k now how t o f orw ar d t he p ack et t o t he next hop. I f t he r out er d oes n ot k now

  Pub Dat e: Sep tem ber 1 1, 2 003

  how t o f or war d t he packet , it t y pically d rop s t he packet . I f t he rou t er kn ow s how t o f orw ar d t he

  I SBN: 1- 58 705 -1 19 -2

  pack et , how ever , it ch anges t h e dest in at ion p hy sical ad dr ess t o t hat of t he next hop and

  Pages: 11 28 t r ansm it s t he p acket .

  The n ex t hop m ay be t h e ult im at e dest inat ion host . I f not , t he n ex t hop is usually anot h er rou t er, w hich ex ecu t es t he sam e sw it ch in g d ecision p rocess. As t he p ack et m ov es t hr oug h t h e int er net w ork , it s phy sical addr ess ch anges, bu t it s p rot ocol addr ess rem ains const ant , as illust rat ed in Figur e 6- 2 . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  

Figu r e 6 - 2 . Nu m er ou s Rout er s M a y Com e i nt o Pla y Du r in g t he

nov ice t o ex pert .

  

Sw i t ch in g Pr oce ss

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The p r eceding discussion descr ibes sw it ch ing bet w een a sour ce and a dest in at ion end sy st em . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The I n t er nat ion al Or gan izat ion f or St and ar dizat ion ( I SO) has developed a hier archical indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . t er min olog y t hat is useful in d escr ib ing t his p rocess. Using t his t er m in ology , net w or k devices Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, w it hout t h e cap abilit y t o f or w ard pack et s bet w een subn et w or k s ar e called end syst em s ( ESs) , and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all w her eas net w ork d ev ices wit h t h ese capab ilit ies ar e called int erm ediat e syst em s ( I Ss) . I Ss ar e net w or kin g p rof essionals, r egar dless of ex pert ise. fu r t her div ided in t o t h ose t hat can com mu nicat e w it hin rou t ing dom ains ( int r adom ain I Ss) and t hose t h at com m unicat e bot h w it h in an d b et w een r ou t ing dom ains ( int erd om ain I Ss) . A r out ing Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e dom ain gener ally is consider ed a por t ion of an int er net w or k un der comm on adm inist r at ive har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on aut h or it y t hat is regu lat ed b y a p art icular set of ad min ist r at iv e guid elines. Rou t ing dom ains ar e a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions also called aut on omou s syst em s. Wit h cer t ain pr ot ocols, r out in g d om ain s can b e div ided in t o t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . r out ing ar eas, but int r adom ain rou t ing pr ot ocols ar e st ill used f or sw it chin g b ot h wit h in an d Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy bet w een ar eas. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Routing Algorithms

  Rou t in g algorit hm s

  can be d iff er ent iat ed based on sev eral key char act erist ics. Fir st , t he par t icular goals of t he algor it hm design er aff ect t he op er at ion of t he r esu lt ing rou t ing pr ot ocol. Secon d, v ar ious t y pes of r out ing algor it hm s ex ist , and each algor it hm has a diff er ent imp act on

  • Table of Content s

  net w or k and r out er r esou rces. Fin ally , r out in g alg orit h ms use a v ar iet y of met r ics t hat aff ect

  I ndex • calcu lat ion of opt im al rou t es. Th e follow ing sect ions analyze t hese rou t ing algor it hm at t r ibu t es.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. Design Goals

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  Rou t ing algor it hm s oft en hav e one or m ore of t he f ollow ing design goals:

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Op t imalit y Sim plicit y an d low over head Rob ust ness and st abilit y

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Rap id conv erg en ce essent ial an d cu t t ing- edg e t ech nologies.

  Flex ibilit y Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  Op t im alit y r efer s t o t he capab ilit y of t h e r out ing algor it hm t o select t he best r out e, wh ich nov ice t o ex pert .

  depend s on t he m et r ics an d m et r ic w eig ht ing s used t o m ake t he calcu lat ion . For exam ple, on e r out ing algor it hm may use a n um ber of hop s and delays, b ut it m ay w eig h delay mor e h eav ily in New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP t he calculat ion. Nat ur ally , r out in g pr ot ocols m u st defin e t heir m et ric calculat ion alg orit h m s

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age st r ict ly . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Rou t ing algor it hm s also ar e desig ned t o be as sim ple as possib le. I n ot her w or ds, t h e r out ing algor it hm m u st off er it s fu nct ionalit y eff icient ly , w it h a m inim um of soft war e an d ut iliz at ion

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  ov er head. Ef ficiency is p art icular ly im por t ant w hen t he soft w ar e im plement in g t he r out ing enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing algor it hm m u st r un on a com put er w it h limit ed phy sical r esour ces. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Rou t ing algor it hm s m ust b e r obust , w hich m ean s t hat t hey shou ld per for m cor r ect ly in t he f ace Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, of un usual or unf oreseen circum st ances, su ch as h ar dw are failur es, high load con dit ions, and and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all incor rect im plem en t at ions. Becau se rou t ers ar e locat ed at net w or k j unct ion point s, t h ey can net w or kin g p rof essionals, r egar dless of ex pert ise. cause considerab le pr oblems wh en t h ey f ail. The b est rou t ing algor it hm s ar e oft en t h ose t hat hav e w it hst ood t he t est of t ime and t hat hav e pr ov en st able u nder a var iet y of net w or k Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e condit ions. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions I n addit ion, rou t ing algor it hm s m ust conv er ge r apidly . Con ver gen ce is t he pr ocess of ag r eem en t , t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . by all rou t ers, on opt im al r ou t es. Wh en a net w or k ev ent cau ses r out es t o eit her go dow n or Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy becom e available, r out er s dist r ibut e rou t ing upd at e m essages t hat per m eat e net w ork s, syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich st imu lat ing recalcu lat ion of op t imal rou t es and event u ally cau sing all r ou t er s t o agr ee on t hese pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease r out es. Rout in g alg orit h m s t hat conv er ge slow ly can cause r out in g loop s or net w or k out ag es. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient I n t he r out in g loop display ed in decisions for t h eir net w ork s. Figur e 6- 3 , a packet ar riv es at Rout er 1 at t im e t 1 . Rou t er 1 alr ead y has b een upd at ed an d t hus k now s t hat t he opt im al rou t e t o t he dest inat ion calls f or Rou t er 2 t o be t he nex t st op . Rout er 1 t h er efor e f orw ar ds t he p ack et t o Rout er 2 , bu t b ecause t his r ou t er has not y et been u pdat ed , it b elieves t h at t h e opt im al n ex t hop is Rout er 1 . Rou t er 2 been sw it ched t he m ax im u m nu mb er of t im es allow ed .

  

Figu r e 6 - 3 . Sl ow Con ve r gen ce a nd Rou t i ng Loops Can Hi nd er Pr og r ess

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  Rou t ing algor it hm s should also be f lex ible, w hich means t hat t hey should qu ick ly and accu rat ely Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age adap t t o a v ar iet y of net w ork cir cu m st an ces. Assum e, for ex am ple, t hat a net w or k seg m en t h as gon e dow n. As m any r out ing algor it hm s b ecom e aw ar e of t he p r oblem , t hey w ill quickly select Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . t he next - b est pat h f or all r out es nor m ally using t hat segm ent . Rout in g alg orit h ms can be pr ogr am m ed t o adapt t o ch anges in net w or k band w id t h, rou t er queue size, and net w or k delay ,

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat am ong ot her v ar iables.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

Algorithm Types

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Rou t ing algor it hm s can b e classified by t y pe. Key dif ferent iat ors in clu de t hese: net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  St at ic v ersus dy nam ic har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Single- pat h v ersus mu lt ipat h t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  Flat v er sus h ier ar chical syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  Host - int ellig en t v ersus rou t er - int elligent pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  I nt r adom ain ver sus int er dom ain Lin k- st at e v er su s dist ance v ect or

  St at ic r out ing algor it h m s

  ar e h ard ly algor it hm s at all, but ar e t able m app in gs est ablished b y t he net w or k adm inist r at or befor e t he beginn ing of rou t ing. These map pings do n ot chan ge u nless t h e net w or k adm inist r at or alt ers t hem . Algor it hm s t hat use st at ic r out es ar e sim ple t o d esign and w or k w ell in env iron m en t s w her e net w ork t raf fic is relat ively pr edict able an d w h er e net w or k design is relat iv ely sim ple. Becau se st at ic rou t ing sy st ems can not react t o net w or k chang es, t h ey generally ar e considered

  • Table of Content s

  un su it able for t oday 's lar ge, const an t ly ch angin g n et w or k s. Most of t h e dom inant r out ing

  I ndex •

  algor it hm s t od ay ar e dy nam ic r out ing algor it h m s, w hich adj ust t o chang in g net w ork

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  circum st ances by an alyzing incom ing r out ing up dat e m essag es. I f t he messag e indicat es t hat a By Cisco Systems, Inc. net w or k chang e has occur r ed , t he r ou t in g sof t w ar e recalcu lat es rou t es and sen ds out new r out ing up dat e m essag es. Th ese m essages p er m eat e t he n et wor k , st im ulat ing r out er s t o r er un t heir algor it hm s an d ch ange t h eir rou t ing t ables accor din gly. Pub lish er: Cisco Press

  Pub Dat e: Sep tem ber 1 1, 2 003

  Dy nam ic r out ing algor it hm s can be sup plement ed w it h st at ic rou t es w here appr opr iat e. A r out er

  I SBN: 1- 58 705 -1 19 -2

  of last r esor t ( a r out er t o w hich all unr out ab le pack et s are sent ) , for ex am ple, can be desig nat ed

  Pages: 11 28

  t o act as a reposit or y for all unr ou t able pack et s, en su ring t h at all m essag es are at least han dled in som e w ay .

Single-Path Versus Multipath

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Som e sophist icat ed r out ing p rot ocols sup por t m ult ip le pat hs t o t h e sam e d est inat ion . Unlike single- pat h algor it hm s, t hese m ult ipat h algor it hm s p er m it t raf fic m ult ip lex ing over m ult ip le lines. The adv ant ages of m ult ipat h algor it hm s ar e obv ious: Th ey can pr ov ide sub st an t ially bet t er

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom t hr ou ghpu t an d reliabilit y. This is gener ally called load shar ing. nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Flat Versus Hierarchical

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Som e r out ing algor it hm s op er at e in a f lat space, w hile ot h er s u se r out in g hier ar chies. I n a flat Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  r out ing sy st em

  , t h e r out er s are peer s of all ot hers. I n a h ier ar ch ical rou t ing sy st em, som e r out er s for m w h at am oun t s t o a r out ing back bon e. Pack et s fr om n onback bone rou t er s t rav el t o

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  t he backb one r out er s, w here t hey ar e sent t h rou gh t he b ack bon e unt il t hey r each t he general enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing ar ea of t he d est inat ion . At t his poin t , t hey t r av el fr om t h e last back bone rou t er t hr oug h on e or t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing m or e nonb ack bon e r out er s t o t h e fin al dest inat ion. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  Rou t ing sy st ems oft en desig nat e logical g rou ps of nod es, called d omain s, aut onom ous sy st ems, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all or ar eas. I n hierar chical sy st em s, som e r out er s in a dom ain can com m unicat e w it h rou t ers in net w or kin g p rof essionals, r egar dless of ex pert ise. ot her d omain s, w hile ot her s can com m unicat e only w it h r out er s w it hin t heir dom ain. I n v er y lar ge net w or k s, addit ional hier ar chical lev els m ay ex ist , w it h rou t ers at t h e high est hier ar chical Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e level f orm ing t h e r out ing back bone. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions The p r im ar y adv ant age of hier archical r out in g is t hat it m imics t h e or ganizat ion of m ost t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . com panies and t her efor e supp ort s t heir t r aff ic pat t er ns w ell. Most n et w or k com m unicat ion occur s Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy w it hin small com pan y gr oup s ( dom ains) . Because int r adom ain rou t er s n eed t o k now only abou t syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich ot her r out er s w it hin t heir d omain, t heir r out ing algor it hm s can be sim plified, an d, d ep en ding on pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t he rou t ing algor it hm b eing u sed, rou t ing upd at e t r aff ic can b e r ed uced accord in gly . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Host-Intelligent Versus Router-Intelligent and - for w ar d d ev ices, m ind lessly send in g t he pack et t o t he n ex t st op . Ot h er alg or it h m s assu me t hat host s k now n ot hing abou t r out es. I n t hese algor it hm s, rou t ers det er min e t he p at h t hr ough t h e int ern et wor k b ased on t heir ow n calculat ions. I n t he f ir st syst em , t he host s hav e t h e rou t ing int ellig en ce. I n t he lat t er sy st em , rou t er s h ave t he r out ing int ellig en ce.

  • Table of Content s

Intradomain Versus Interdomain

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Som e r out ing algor it hm s w or k only w it h in d omains; ot her s w ork w it h in an d bet w een dom ains.

  By Cisco Systems, Inc.

  The n at ur e of t h ese t w o alg or it h m t y pes is dif fer en t . I t st an ds t o reason, t heref ore, t h at an opt im al in t rad om ain - r out ing algor it hm w ou ld n ot n ecessar ily be an opt im al int er dom ain- r out in g

  Pub lish er: Cisco Press algor it hm .

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Link-State Versus Distance Vector

  Link - st at e algorit hm s

  ( also kn own as sh ort est p at h fir st algor it hm s) f lood r ou t in g in for m at ion t o all nod es in t h e int er net w ork . Each r out er , how ev er , sends only t he por t ion of t h e r out ing t ab le t hat descr ibes t h e st at e of it s ow n lin ks. I n link - st at e algor it hm s, each r out er b uilds a pict ur e of The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he en t ire n et wor k in it s r out in g t ab les. D ist an ce v ect or algor it hm s ( also k now n as Bellm an - For d essent ial an d cu t t ing- edg e t ech nologies. algor it hm s) call f or each r out er t o sen d all or som e p ort ion of it s r out in g t able, but only t o it s neighb or s. I n essence, link - st at e algor it hm s sen d sm all u pdat es ev er y w here, w hile d ist an ce v ect or alg orit h ms send lar ger up dat es only t o neighb orin g r out er s. Dist an ce v ect or alg orit h ms

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom k now on ly about t heir neigh bor s. nov ice t o ex pert .

  Becau se t hey conv er ge m or e q uick ly , link - st at e algor it hm s ar e somew hat less p ron e t o r ou t ing New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP loops t h an dist ance vect or algor it hm s. On t h e ot her h and, link - st at e alg orit h ms requ ir e m or e

  CPU p ow er an d mem or y t han dist ance v ect or algor it hm s. Link - st at e algor it hm s, t h er efor e, can Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age be m or e ex pensiv e t o im plem ent and supp ort . Link - st at e pr ot ocols ar e gener ally mor e scalable t han d ist an ce v ect or pr ot ocols.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

Routing Metrics

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Rou t ing t ables cont ain in for m at ion used by sw it ching soft w ar e t o select t h e best r out e. But how , Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, specif ically , ar e r out ing t ables b uilt ? Wh at is t h e specif ic nat ur e of t h e inf orm at ion t hat t hey and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all cont ain? How do r out ing algor it hm s d et er m in e t hat one r ou t e is pr efer able t o ot hers? net w or kin g p rof essionals, r egar dless of ex pert ise. Rou t ing algor it hm s hav e used man y diff erent m et rics t o det erm ine t he best r out e. Sop hist icat ed Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e r out ing algor it hm s can base r out e select ion on mu lt iple m et r ics, comb in ing t hem in a single har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on ( hy br id) m et r ic. All t h e follow ing m et r ics hav e been used : a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Pat h len gt h syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

  Reliabilit y pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient

  Delay decisions for t h eir net w ork s. Band wid t h Load

  Pat h lengt h

  is t he m ost com m on r out in g met r ic. Some rou t ing pr ot ocols allow net w or k adm inist r at or s t o assign ar bit r ary cost s t o each net w or k link . I n t his case, p at h leng t h is t he sum of t he cost s associat ed w it h each lin k t r aver sed . Ot h er rou t ing pr ot ocols define h op cou nt , a m et ric t hat specifies t he num ber of passes t hr oug h in t er net w or k in g pr oduct s, such as r out er s, t hat a packet mu st t ak e en r out e fr om a sou r ce t o a dest in at ion .

  

Reliabilit y , in t he con t ex t of rou t ing algor it hm s, r ef er s t o t he dependabilit y ( u su ally descr ibed in

  • Table of Content s

  t er ms of t he bit - er r or r at e) of each n et w or k link . Som e net w or k link s m ig ht go d ow n m or e of t en t han ot h er s. Af t er a net w or k fails, cert ain net w or k link s m ight be r epair ed m or e easily or m or e • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  qu ick ly t han ot h er link s. Any reliabilit y fact or s can be t ak en in t o account in t he assig nm en t of t h e r eliabilit y r at ing s, wh ich ar e ar bit r ar y num er ic valu es u su ally assign ed t o net w ork lin ks b y

  By Cisco Systems, Inc.

  net w or k adm inist r at or s.

  Pub lish er: Cisco Press Rou t in g delay

  r efer s t o t he lengt h of t im e r equir ed t o m ove a pack et f rom sou rce t o dest inat ion

  Pub Dat e: Sep tem ber 1 1, 2 003

  t hr ou gh t he int er net w or k. Delay depends on m any fact or s, in clu ding t he bandw id t h of

  I SBN: 1- 58 705 -1 19 -2

  int er m ed iat e net w ork lin ks, t h e por t queues at each r out er along t he way , n et w or k cong est ion on

  Pages: 11 28

  all int er m ed iat e net w or k lin ks, an d t he ph ysical dist ance t o be t r av eled. Because d elay is a conglom erat ion of sever al im por t ant var iables, it is a comm on and usefu l m et ric.

  Band widt h r efer s t o t he av ailable t r aff ic capacit y of a link . All ot h er t hings being eq ual, a 10-

  Mb ps Et h er n et link w ould be p ref er able t o a 6 4- k bps leased line. Alt h ough ban dw idt h is a r at ing of t he max im um at t ain able t hr ou ghpu t on a lin k, rou t es t hr oug h link s w it h gr eat er band w id t h do The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of not necessar ily p rov ide b et t er rou t es t han r out es t hr ou gh slow er link s. For ex am ple, if a f ast er essent ial an d cu t t ing- edg e t ech nologies. link is b usier , t h e act ual t im e r equir ed t o sen d a pack et t o t he dest inat ion could be gr eat er.

  Load

  r efer s t o t he d eg ree t o w hich a net w or k resour ce, su ch as a r out er , is busy . Load can be Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom calcu lat ed in a v ar iet y of w ay s, including CPU ut ilizat ion an d p acket s p rocessed per second . nov ice t o ex pert . Mon it or ing t h ese p aram et ers on a cont inual basis can b e r esour ce- in t ensiv e it self .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  Com m un icat ion cost is anot her im por t ant m et ric, especially because some com pan ies m ay n ot

  care about per for m ance as m uch as t hey car e about oper at ing exp en dit ur es. Alt houg h line d elay Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age m ay be lon ger, t hey w ill sen d p ack et s ov er t heir ow n lin es r at h er t han t hr oug h t he pu blic lines t hat cost m oney f or usage t im e.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Network Protocols

  Rou t ed p rot ocols ar e t r anspor t ed by r out in g p rot ocols acr oss an in t er n et w or k . I n g en er al, r out ed pr ot ocols in t his cont ex t also ar e r efer red t o as net w ork p r ot ocols. Th ese net w or k pr ot ocols per for m a var iet y of fu nct ions r equir ed f or com mu nicat ion b et ween user applicat ions in sou r ce

  Table of Content s •

  and dest inat ion dev ices, and t hese fu nct ions can diff er w idely amon g p r ot ocol su it es. Net w or k

  I ndex •

  pr ot ocols occu r at t he up per f iv e lay er s of t h e OSI r efer en ce mod el: t he n et wor k lay er, t he

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion t r anspor t lay er , t he session layer , t h e pr esent at ion lay er , an d t he app licat ion layer .

  By Cisco Systems, Inc.

  Con fusion about t he t er m s r out ed pr ot ocol an d r out ing pr ot ocol is com m on. Rout ed pr ot ocols are pr ot ocols t hat ar e r out ed over an int er net w ork . Exam p les of such pr ot ocols ar e t he I nt er net

  Pub lish er: Cisco Press

  Pr ot ocol ( I P) , DECnet , Ap pleTalk , Nov ell Net W are, OSI , Ban yan VI NES, an d Xer ox Net w or k

  Pub Dat e: Sep tem ber 1 1, 2 003

  Sy st em ( XNS) . Rout in g p rot ocols, on t he ot her han d, ar e pr ot ocols t hat im plement r out ing

  I SBN: 1- 58 705 -1 19 -2

  algor it hm s. Put sim p ly , r out in g pr ot ocols are u sed by in t er m ediat e syst em s t o build t ables used

  Pages: 11 28

  in det er m ining pat h select ion of rou t ed p rot ocols. Ex am ples of t hese pr ot ocols include I n t er ior Gat ew ay Rou t ing Pr ot ocol ( I GRP) , Enhan ced I nt er ior Gat ew ay Rout in g Pr ot ocol ( Enhan ced

  I GRP) , Open Shor t est Pat h Fir st ( OSPF) , Ex t er ior Gat ew ay Pr ot ocol ( EGP) , Bor der Gat ew ay Pr ot ocol ( BGP) , I n t er m ediat e Sy st em - t o- I nt er m ed iat e Sy st em ( I S- I S) , an d Rout ing I nf orm at ion Pr ot ocol ( RI P) . Rout ed and rou t ing pr ot ocols ar e discu ssed in d et ail lat er in t his book .

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Review Questions 1 : Descr ibe t he pr ocess of r out in g packet s.

  Table of Content s • 2 : I ndex

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  What ar e some rou t ing algor it hm t y pes?

  3 : Descr ibe t he dif fer en ce b et ween st at ic and dy nam ic r out ing .

  By Cisco Systems, Inc.

  4 :

  What ar e some of t he m et r ics u sed by r out in g p r ot ocols?

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 7. Network Management Basics Obj e ct i ve Table of Content s • Becom e f am iliar w it h t he basic fun ct ion s of a n et wor k m anag em ent syst em . I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction

  This chap t er descr ibes fu nct ions com m on t o m ost net w or k - man agem en t ar chit ect u r es an d pr ot ocols. I t also pr esen t s t he fiv e con cept ual ar eas of m anagem en t as defined by t h e I nt er nat ional Or ganizat ion for St andar dizat ion ( I SO) . Su bseq uent ch apt er s in Par t VI I I ,

  Table of Content s •

  " Net w ork Managem ent , " ad dr ess specific n et w or k m anag em ent t echn ologies, p r ot ocols, an d

  I ndex • plat f or ms in m or e det ail.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

What Is Network Management?

  Net w ork m an agem ent

  m eans d iff er ent t hing s t o d iffer ent people. I n som e cases, it in volv es a solit ary n et wor k consult an t m onit or ing net w or k act ivit y wit h an out d at ed p rot ocol analyzer . I n ot her cases, n et wor k m an agement inv olves a dist rib ut ed d at abase, aut op ollin g of n et w or k

  • Table of Content s

  dev ices, and hig h- end w ork st at ions g en er at ing r eal- t ime g r aphical v iew s of n et w or k t op ology

  I ndex •

  chang es and t r aff ic. I n gener al, net w or k m anagem en t is a ser v ice t h at em ploy s a v ar iet y of

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  t ools, app licat ions, an d d ev ices t o assist hum an net w or k m anager s in mon it orin g an d By m aint aining n et w or k s. Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

A Historical Perspective

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The ear ly 19 80s saw t rem endous ex pan sion in t he ar ea of net w or k deploy m en t . As com panies r ealized t he cost b en ef it s and pr odu ct iv it y g ain s creat ed by net w or k t echnology , t h ey began t o add net w or k s and exp and ex ist ing net w ork s alm ost as r ap id ly as new n et w or k t echnolog ies an d pr odu ct s w er e int rod uced . By t he mid - 198 0s, cer t ain comp anies w er e ex periencing gr ow ing pains fr om d ep loy ing m any d if fer ent ( and som et im es in com pat ib le) net w or k t ech nologies. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of The p r oblem s associat ed w it h net w ork ex pan sion aff ect bot h day - t o- d ay net w or k oper at ion essent ial an d cu t t ing- edg e t ech nologies. m anagem ent and st r at egic n et wor k g row t h p lan ning. Each new net w or k t ech nology r equir es it s ow n set of ex per t s. I n t he early 1 980 s, t he st af fing r equir em ent s alon e for man aging lar ge, het er ogeneous net w or k s cr eat ed a crisis f or m any or ganizat ion s. An u rg en t n eed ar ose f or

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom aut om at ed net w or k m anagem en t ( in clud ing w hat is t yp ically called net w or k capacit y plann in g) nov ice t o ex pert . int egr at ed acr oss div erse env iron m en t s.

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Network Management Architecture Most net w ork m an agement ar ch it ect u res u se t he sam e basic st ru ct ur e and set of r elat ionship s.

  En d st at ion s ( m anaged devices) , su ch as com pu t er sy st ems and ot her net w or k dev ices, r un soft w ar e t h at enables t h em t o send aler t s w h en t hey r ecog nize pr ob lem s ( f or exam ple, w hen one

  • Table of Content s

  or m or e user- det er m ined t hr eshold s ar e ex ceeded) . Up on receiv ing t hese aler t s, m anag em ent

  • I ndex

  ent it ies ar e pr ogr am med t o react b y ex ecut ing one, sever al, or a gr oup of act ion s, inclu ding

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion oper at or not if icat ion , event loggin g, sy st em shu t dow n, and aut om at ic at t em pt s at sy st em r epair .

  By Cisco Systems, Inc.

  Man agement ent it ies also can p oll en d st at ion s t o ch eck t h e valu es of cer t ain v ar iables. Polling can be aut om at ic or user - init iat ed, but agent s in t h e man aged devices respon d t o all polls.

  Pub lish er: Cisco Press

  Agent s are sof t w are mod ules t hat fir st com pile inf orm at ion abou t t h e m anaged devices in w h ich

  Pub Dat e: Sep tem ber 1 1, 2 003

  t hey r esid e, t hen st or e t h is infor m at ion in a m anagem en t d at abase, and fin ally p rov ide it

  I SBN: 1- 58 705 -1 19 -2

  ( pr oact iv ely or r eact ively) t o man agem en t ent it ies w it hin net w ork man agem en t sy st em s ( NMSs)

  Pages: 11 28

  v ia a n et wor k m an agement pr ot ocol. Well- kn own n et w or k m anag em ent pr ot ocols in clu de t h e Sim ple Net w ork Managem en t Pr ot ocol ( SNMP) and Com m on Manag em ent I n for m at ion Prot ocol ( CMI P) . Manag em ent pr oxies ar e ent it ies t hat pr ov id e m anagem ent in for m at ion on b eh alf of ot her ent it ies. Figur e 7- 1 d ep ict s a t y pical net w or k m anag em ent archit ect ur e.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  

Figu r e 7 - 1 . A Ty pi cal N et w or k M an age m e nt Ar chi t e ct u r e M ai nt ai ns

M a ny Rel at ionshi ps

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ISO Network Management Model

  The I SO has cont rib ut ed a gr eat d eal t o n et w or k st and ard izat ion. I t s n et w or k m anag em ent m odel is t h e pr imar y m eans f or un der st an ding t he maj or f unct ions of n et w or k m anag em ent syst em s. This m odel consist s of fiv e concep t ual ar eas, as discussed in t he n ex t sect ions.

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Performance Management By Cisco Systems, Inc.

  The g oal of per for m ance m anagem en t is t o m easu re and mak e av ailable v ariou s aspect s of

  Pub lish er: Cisco Press

  net w or k per for m ance so t h at int er net w or k per for m ance can b e m ain t ained at an accept ab le

  Pub Dat e: Sep tem ber 1 1, 2 003

  level. Ex am ples of per for m ance var iables t h at m ight be pr ovided include n et wor k t h r ough put ,

  I SBN: 1- 58 705 -1 19 -2 user r espon se t imes, and line u t ilizat ion . Pages: 11 28

  Perf or man ce man agem en t inv olv es t hr ee m ain st ep s. Fir st , per for m ance dat a is gat hered on v ariab les of int er est t o net w ork adm in ist r at or s. Secon d, t he dat a is analy zed t o det erm ine nor m al ( b aseline) levels. Fin ally , ap pr opr iat e per for m ance t hr esholds ar e d et er m in ed f or each im por t ant var iable so t hat ex ceedin g t h ese t h r esholds in dicat es a net w or k pr oblem w or t hy of at t ent ion . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Man agement ent it ies con t inually m onit or perf or man ce var iables. When a per for m ance t hr eshold is exceed ed , an aler t is gener at ed and sent t o t h e net w or k m anagem en t sy st em .

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Each of t he st eps j ust descr ibed is p ar t of t h e pr ocess t o set up a r eact iv e sy st em . Wh en nov ice t o ex pert . per for m ance becom es u naccept able because of an ex ceeded user- d ef ined t hr eshold , t he sy st em r eact s b y sen ding a m essag e. Per f orm ance m anag em ent also per mit s pr oact iv e m et hods: For

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP exam ple, n et w or k sim ulat ion can be u sed t o pr oject how net w or k gr ow t h w ill affect p er f orm an ce m et rics. Such sim ulat ion can aler t ad m in ist r at or s t o imp en ding pr oblem s so t h at coun t er act ive

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age m easu res can be t ak en. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

Configuration Management

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The g oal of conf igur at ion m an agem ent is t o m onit or n et wor k an d sy st em con figu rat ion indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . inf orm at ion so t h at t h e ef fect s on net w or k oper at ion of v ar ious v ersions of h ard w are and Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, soft w ar e elem ent s can be t rack ed an d m anag ed . and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Each net w or k device has a v ar iet y of v ersion infor m at ion associat ed w it h it . An engin eer in g w or kst at ion, for ex am ple, m ay be conf igur ed as follow s: Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Op er at ing syst em , Version 3. 2 t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  Et h er n et int er face, Ver sion 5 . 4 syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  TCP/ I P sof t w ar e, Ver sion 2 .0 pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Net War e sof t w ar e, Ver sion 4 . 1

  NFS soft w ar e, Version 5. 1

  SNMP sof t w ar e, Ver sion 3 .1 Con figu rat ion m anag em ent su bsyst em s st ore t his inf or mat ion in a d at abase for easy access. When a p rob lem occur s, t h is dat abase can be searched for clu es t hat m ay h elp solve t he pr oblem .

  • Table of Content s

Accounting Management

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  The g oal of accou nt ing m an agem ent is t o m easu re net w ork u t ilizat ion p aram et ers so t hat By Cisco Systems, Inc. indiv idual or gr oup u ses on t he net w ork can be r egu lat ed app rop riat ely . Such regu lat ion m inim izes n et w or k p rob lem s ( b ecause n et w or k r esou rces can b e app ort ion ed based on r esour ce

  Pub lish er: Cisco Press capacit ies) and max im izes t he f air n ess of net w or k access acr oss all user s.

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

  As w it h per for m ance m anagem en t , t h e fir st st ep t owar d app rop riat e accoun t ing m anagem en t is t o measur e ut ilizat ion of all im por t ant net w ork resour ces. An aly sis of t he r esult s pr ov ides insight Pages: 11 28 int o cu r rent usage p at t ern s, and usage q uot as can be set at t his p oint . Som e cor rect ion, of cour se, w ill b e r eq uir ed t o reach opt im al access pr act ices. Fr om t his p oint , on going m easu rem en t of r esou r ce u se can y ield billing infor m at ion as w ell as inf orm at ion used t o assess cont inu ed f air and opt im al r esou rce u t ilizat ion .

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Fault Management

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The g oal of fau lt m anagem en t is t o det ect , log, n ot ify u ser s of , and ( t o t he ex t en t p ossible) nov ice t o ex pert . aut om at ically fix n et w or k pr ob lem s t o keep t he net w or k r unn ing ef fect ively . Becau se f ault s can cause dow nt im e or unaccep t able net w or k degr adat ion , fau lt m anag em ent is per haps t he m ost

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP w idely imp lem ent ed of t he I SO net w ork man agement elem ent s. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Fault m an agement inv olves f irst det er m ining sym p t om s and isolat in g t h e pr oblem . Then t he pr oblem is f ixed and t he solut ion is t est ed on all- imp or t ant su bsyst em s. Finally , t h e det ect ion Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . and r esolut ion of t h e pr oblem is r ecor ded.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

Security Management indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, The g oal of secur it y m anagem en t is t o cont r ol access t o net w or k r esour ces accor ding t o local and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all gu id elines so t hat t he n et w or k cannot be sab ot aged ( in t ent ionally or u nint ent ionally ) an d net w or kin g p rof essionals, r egar dless of ex pert ise. sen sit iv e inf orm at ion cannot be accessed by t hose w it hou t ap pr opr iat e aut h or izat ion . A secur it y m anagem ent su bsyst em , for ex am ple, can m on it or user s log ging on t o a net w ork resour ce and

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e can refu se access t o t h ose wh o ent er inap pr opr iat e access codes. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Secu rit y man agement subsy st em s w or k by par t it ioning net w or k r esour ces int o au t hor ized an d t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . un aut hor ized areas. For some user s, access t o any net w or k r esou rce is inap pr opr iat e, m ost ly

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy because such u ser s ar e usually com pany out siders. For ot h er ( int ern al) net w or k user s, access t o syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich inf orm at ion or iginat ing f rom a par t icular d ep art m ent is inapp rop r iat e. Access t o Hum an pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  Resour ce files, f or ex amp le, is in appr opr iat e f or m ost user s out side t h e Hum an Resou rces pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient depar t m ent . decisions for t h eir net w ork s.

  Secu rit y man agement subsy st em s p er f orm sev er al f un ct ion s. They ident ify sensit ive net w ork r esour ces ( including sy st em s, files, and ot her ent it ies) and d et er m in e m appin gs bet w een sen sit iv e net w or k r esour ces and user set s. Th ey also mon it or access point s t o sensit ive n et wor k

  Review Questions 1 : Nam e t he d iff er ent areas of n et w or k m anag em ent .

  • Table of Content s
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  2 : I ndex

  What ar e t he goals of per for m ance m anagem en t ?

  3 :

  What ar e t he goals of config ur at ion m an agement ? By Cisco Systems, Inc.

  4 :

  What ar e t he goals of accou nt ing m anagem ent ?

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 5 :

  What ar e t he goals of fau lt m anag em ent ?

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 6 :

  What ar e t he goals of secur it y m anag em ent ? The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Part II: LAN Protocols Ch apt er 8 Et her net Technologies Ch apt er 9 Fiber Dist r ibut ed Dat a I nt erf ace

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 8. Ethernet Technologies Obj e ct i ve s Table of Content s • Under st and t he r equir ed an d opt ional MAC f r ame for m at s, t heir pu rp oses, and t h eir I ndex • com pat ibilit y r eq uir em ent s. I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. List t he v ar iou s Et h er net phy sical lay er s, sign alin g pr ocedu res, and link m edia r eq uir em ent s/ lim it at ion s. Pub lish er: Cisco Press Descr ibe t he t r ade- off s associat ed w it h im plem en t ing or up gr ading Et h er n et Pub Dat e: Sep tem ber 1 1, 2 003 LANs—choosing dat a rat es, op er at ional mod es, an d net w ork equ ipm en t . I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Background

  The t er m Et h er n et r efer s t o t he f am ily of local- ar ea net w ork ( LAN) pr oduct s cov er ed by t h e I EEE 80 2. 3 st an dar d t hat defines w hat is com mon ly kn ow n as t he CSMA/ CD pr ot ocol. Thr ee dat a r at es ar e cu rr ent ly d ef ined f or op er at ion over op t ical fiber an d t w ist ed- pair cab les:

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  10 Mb ps— 10Base- T Et hern et By Cisco Systems, Inc. 10 0 Mbps— Fast Et her net

  Pub lish er: Cisco Press

  10 00 Mbp s— Gigabit Et h er net

  Pub Dat e: Sep tem ber 1 1, 2 003

  10 - Gigabit Et h er net is und er developm ent and w ill lik ely be pu blish ed as t he I EEE 8 02. 3ae

  I SBN: 1- 58 705 -1 19 -2 supp lem ent t o t h e I EEE 80 2. 3 base st andar d in lat e 200 1 or ear ly 20 02. Pages: 11 28

  Ot h er t echn ologies and pr ot ocols hav e been t ou t ed as lik ely replacement s, but t he m ar k et has spok en . Et h er n et has sur v ived as t he maj or LAN t ech nology ( it is cur rent ly used f or app rox im at ely 85 percent of t he w or ld' s LAN- connect ed PCs and w or kst at ion s) because it s pr ot ocol h as t he f ollowin g char act erist ics: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  I s easy t o un der st an d, im plem en t , m anage, an d m aint ain Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Allow s low- cost net w ork im plem en t at ions nov ice t o ex pert . Pr ovid es ex t ensive t op ological flex ib ilit y f or n et w or k inst allat ion New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Gu aran t ees successfu l int er con nect ion an d op er at ion of st andar ds- com pliant pr oduct s, Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age r eg ar dless of m anu fact ur er Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Ethernet—A Brief History

  The or igin al Et h er net w as developed as an ex per im en t al coaxial cab le net w ork in t h e 197 0s b y Xerox Cor por at ion t o oper at e w it h a d at a r at e of 3 Mbp s using a car r ier sense m ult iple access collision det ect ( CSMA/ CD) p rot ocol for LANs w it h spor ad ic but occasionally heav y t r aff ic

  • Table of Content s

  r eq uir em ent s. Su ccess wit h t h at p roj ect at t r act ed ear ly at t ent ion and led t o t he 1 980 join t

  I ndex •

  dev elop ment of t he 1 0- Mb ps Et hern et Version 1. 0 sp ecificat ion by t h e t hr ee- com pan y

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion consor t iu m : Dig it al Equ ipm en t Corp orat ion , I nt el Corp orat ion , and Xerox Cor por at ion.

  By Cisco Systems, Inc.

  The or igin al I EEE 80 2. 3 st an dar d w as based on , and w as v er y sim ilar t o, t he Et her net Ver sion 1. 0 specif icat ion . The d raf t st an dar d w as appr ov ed by t he 8 02. 3 w ork ing gr oup in 19 83 and w as

  Pub lish er: Cisco Press

  subsequent ly published as an off icial st an dar d in 19 85 ( ANSI / I EEE St d. 8 02. 3 - 198 5) . Since t h en ,

  Pub Dat e: Sep tem ber 1 1, 2 003

  a n um ber of supp lem ent s t o t he st an dar d hav e been d ef ined t o t ak e adv ant ag e of im pr ovem en t s

  I SBN: 1- 58 705 -1 19 -2

  in t he t echnolog ies an d t o supp ort add it ion al net w or k m edia and h ig her dat a r at e capabilit ies,

  Pages: 11 28 plus sev er al new opt ional net w or k access con t r ol feat u res.

  Thr oug hout t he rest of t h is ch apt er , t he t er m s Et h er n et an d 80 2. 3 w ill r efer ex clusiv ely t o net w or k im plem ent at ion s comp at ible w it h t he I EEE 8 02. 3 st andar d. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Ethernet Network Elements

  Et h er n et LANs consist of net w or k nod es and int erconn ect ing m edia. The net w ork nodes f all int o t w o m aj or classes:

  Table of Content s • D a t a t er m ina l e qui pm en t ( D TE)

  I ndex — Devices t hat are eit h er t he sour ce or t he dest in at ion • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  of dat a fr am es. DTEs ar e t y pically devices such as PCs, w or kst at ions, f ile ser v er s, or p rint ser v ers t hat , as a gr oup , ar e all of t en r efer red t o as en d st at ions.

  By Cisco Systems, Inc.

  D a t a com m uni cat i on equ ipm e nt ( D CE)

  — I n t er m ediat e net w or k dev ices t h at r eceiv e and

  Pub lish er: Cisco Press

  for w ar d fr am es acr oss t he net w ork . D CEs m ay b e eit h er st andalone d ev ices su ch as

  Pub Dat e: Sep tem ber 1 1, 2 003

  r ep eat er s, net w or k sw it ch es, an d r out er s, or com m unicat ions int er face u nit s such as

  I SBN: 1- 58 705 -1 19 -2 int er face car ds and m odem s. Pages: 11 28

  Thr oug hout t his chap t er, st an dalone in t er m ediat e net w or k dev ices w ill be r efer r ed t o as eit her

  int erm ediat e nod es or DCEs. Net w or k int er face card s w ill be r efer red t o as NI Cs.

  The cu rr ent Et her net m edia opt ions in clud e t w o g en er al t yp es of copp er cab le: unshielded t w ist ed - pair ( UTP) an d sh ielded t w ist ed- p air ( STP) , p lu s sev eral t y pes of opt ical f ib er cab le. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Ethernet Network Topologies and Structures

  LANs t ake on m any t opological config ur at ions, bu t r egar dless of t heir size or com p lex it y, all w ill be a comb inat ion of only t hr ee basic int er connect ion st r uct ur es or n et w or k b uilding blocks.

  • Table of Content s

  The sim plest st r uct ur e is t he point - t o- point in t erconn ect ion, sh ow n in Figur e 8- 1 . Only t w o

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ndex

  net w or k un it s are in volv ed, an d t he connect ion may b e DTE- t o- DTE, DTE- t o- D CE, or DCE- t o-

  DCE. The cab le in p oin t - t o- poin t int er connect ions is k now n as a net w ork lin k. Th e m axim um allow able len gt h of t he lin k depends on t h e t y pe of cable an d t h e t r ansm ission met hod t h at is

  By Cisco Systems, Inc.

  used.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

Figu r e 8 - 1 . Exa m ple Poin t - t o- Poin t I n t er conn ect ion

  Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The or igin al Et h er net net w ork s w er e imp lem ent ed w it h a coaxial b us st r uct ur e, as show n in nov ice t o ex pert .

  Figur e 8- 2 . Segm ent leng t hs w er e limit ed t o 5 00 m et er s, and up t o 100 st at ions cou ld b e

  connect ed t o a sing le segm ent . I n divid ual segm en t s could be int er connect ed w it h r ep eat er s, as New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP long as m ult iple p at hs d id n ot ex ist bet w een any t wo st at ions on t he net w ork and t he n um ber of

  DTEs did not ex ceed 10 24. Th e t ot al p at h dist ance bet w een t h e most - d ist an t p air of st at ion s w as Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age also not allow ed t o ex ceed a m ax imu m pr escr ibed value.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

Figu r e 8 - 2 . Exa m ple Coax ia l Bus Topol ogy

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. connect ed n et w or k s do st ill ex ist and ar e st ill usefu l. Since t he ear ly 19 90s, t h e net w or k config ur at ion of choice has been t h e st ar- conn ect ed t opology , show n in Figur e 8- 3 . Th e cent ral net w ork unit is eit h er a m ult ipor t repeat er ( also k now n as a hu b) or a n et w or k sw it ch . All conn ect ions in a st ar net w ork are p oint - t o- p oin t link s im plem en t ed w it h eit h er t w ist ed- p air or opt ical f iber cable.

  Table of Content s • I ndex •

Figu r e 8 - 3 . Exa m ple St a r - Conn ect e d Topolog y

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  The IEEE 802.3 Logical Relationship to the ISO Reference Model

Figur e 8- 4 sh ows t he I EEE 8 02. 3 logical lay er s and t h eir r elat ionship t o t h e OSI r efer en ce mod el.

  • I ndex

  Table of Content s

  As w it h all I EEE 80 2 pr ot ocols, t h e I SO d at a link lay er is div ided in t o t w o I EEE 80 2 sub layer s,

  t he Med ia Access Con t r ol ( MAC) sublay er and t he MAC- client sublay er. The I EEE 8 02. 3 ph ysical

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion lay er cor r espon ds t o t he I SO ph ysical layer .

  By Cisco Systems, Inc.

  Pub lish er: Cisco Press

Figu r e 8 - 4 . Et he r ne t ' s Logi cal R el at ion sh ip t o t he I SO Re fe r e nce M od el

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . The MAC- client sublay er m ay be on e of t he f ollow ing : Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all

  Log ical Link Cont r ol ( LLC) , if t h e un it is a D TE. Th is su blay er p r ovides t h e int er face bet w een net w or kin g p rof essionals, r egar dless of ex pert ise. t he Et her net MAC an d t he up per layer s in t he p rot ocol st ack of t h e end st at ion . The LLC Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e sublay er is defined by I EEE 802 .2 st and ard s. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on

  Br idge ent it y , if t h e unit is a D CE. Br idg e ent it ies pr ovid e LAN- t o- LAN int er faces bet w een a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions LANs t hat u se t he sam e pr ot ocol ( f or exam ple, Et hern et t o Et her net ) and also bet w een t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . dif fer en t pr ot ocols ( f or exam ple, Et hern et t o Token Ring ) . Br id ge ent it ies ar e defin ed by

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy I EEE 8 02. 1 st andar ds. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Becau se sp ecificat ions f or LLC and br idge ent it ies ar e com mon f or all I EEE 8 02 LAN p r ot ocols, pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient net w or k comp at ibilit y becomes t h e pr im ary r esponsibilit y of t he par t icu lar net w ork pr ot ocol. decisions for t h eir net w ork s.

  Figur e 8- 5 sh ows diff er ent com p at ibilit y requ irem ent s im posed b y t he MAC an d p hy sical lev els for basic dat a com m un icat ion ov er an Et her net link .

  

Figu r e 8 - 5 . M AC a nd Phy si ca l Lay er Com pa t i bil it y Re qui r em e nt s f or

Ba si c D at a Com m u ni cat ion

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  The MAC lay er cont r ols t he n ode's access t o t h e net w ork media and is specif ic t o t h e indiv idual pr ot ocol. All I EEE 8 02. 3 MACs mu st m eet t he sam e basic set of logical r equir em ent s, r egar dless Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age of w het her t h ey in clu de one or m ore of t he defin ed opt ion al pr ot ocol ex t en sion s. The only r eq uir em ent for b asic com m un icat ion ( comm u nicat ion t h at d oes n ot r equir e op t ion al pr ot ocol Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ext ensions) bet w een t w o n et w or k n odes is t hat bot h MACs mu st supp or t t h e sam e t ran sm ission r at e.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing The 8 02. 3 ph ysical layer is specific t o t he t ran sm ission dat a r at e, t he sign al encoding, and t he t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t y pe of m edia in t er connect ing t he t w o nod es. Gig abit Et her net , f or ex am ple, is def in ed t o indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . oper at e ov er eit h er t w ist ed- p air or opt ical f iber cable, but each specif ic t y pe of cable or sign al- Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, encoding pr oced ur e r eq uir es a dif fer en t p hy sical lay er im p lem ent at ion. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The Ethernet MAC Sublayer

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  The MAC sub layer h as t w o p rim ar y r espon sib ilit ies: Dat a encapsulat ion, includ ing fr am e assem bly bef ore t ran sm ission , and f ram e par sing/ er r or det ect ion du rin g an d aft er r ecept ion Media access con t rol, in clu ding init iat ion of fr am e t r ansm ission an d recover y fr om t r ansm ission failur e

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

The Basic Ethernet Frame Format

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Sou rce ad dre sse s ( SA ) — Consist s of 6 by t es. Th e SA f ield ident ifies t h e sen ding st at ion.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  

Fra m e ch eck se que nce ( FCS) — Consist s of 4 by t es. Th is sequ en ce con t ains a 32- b it

  — I s a seq uence of n b yt es of an y v alu e, w here n is less t han or equ al t o 150 0. I f t he lengt h of t he Dat a f ield is less t han 46, t he D at a f ield m ust b e ex t end ed by adding a filler ( a pad ) suf ficien t t o br ing t he D at a f ield len gt h t o 46 by t es.

  D a t a

  dat a by t es t hat ar e cont ained in t h e dat a field of t he f ram e, or t h e fr am e t y pe I D if t he fr am e is assem bled using an opt ional for m at . I f t he Len gt h/ Ty pe field v alue is less t han or equal t o 1 500 , t he n um ber of LLC by t es in t h e Dat a field is equ al t o t he Leng t h/ Ty pe f ield v alue. I f t he Leng t h/ Ty pe f ield v alue is gr eat er t han 1 536, t he f r ame is an op t ional t y pe fr am e, and t h e Lengt h/ Ty pe f ield valu e ident ifies t he par t icu lar t y pe of f ram e b eing sent or r eceived.

  

Le ng t h/ Typ e — Consist s of 4 by t es. Th is field in dicat es eit her t h e nu mb er of MAC- client

  The SA is alw ays an ind ividu al add r ess and t h e lef t - m ost bit in t he SA field is alw ay s 0.

  should r eceive t he f ram e. The lef t - m ost bit in t h e DA field ind icat es w het h er t he add r ess is an indiv idual addr ess ( indicat ed b y a 0 ) or a gr oup add ress ( ind icat ed by a 1) . Th e second bit fr om t h e lef t in dicat es wh et her t he D A is glob ally ad m in ist er ed ( in dicat ed by a 0) or locally ad m in ist er ed ( in dicat ed by a 1) . The r emain in g 4 6 bit s ar e a u niqu ely assigned v alue t hat ident if ies a sin gle st at ion, a defin ed gr oup of st at ions, or all st at ions on t he net w or k.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  D e st i na t ion a ddr ess ( D A) — Consist s of 6 by t es. Th e DA field ident if ies w h ich st at ion( s)

  — Consist s of 1 by t e. The SOF is an alt er nat ing pat t er n of ones an d zer os, en ding w it h t w o consecu t ive 1 - bit s in dicat in g t hat t he nex t b it is t h e lef t - m ost bit in t he left - m ost b yt e of t he d est inat ion add ress.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  t hat t ells receiv ing st at ions t h at a fr am e is com in g, an d t hat pr ovides a m ean s t o syn ch r onize t he f r am e- r ecept ion p ort ion s of receiv ing ph ysical layer s w it h t he in com ing bit st r eam .

  P re am bl e ( P RE) — Consist s of 7 by t es. Th e PRE is an alt er nat in g pat t er n of on es and zer os

  The I EEE 802 .3 st and ard d ef ines a b asic d at a f r ame f or m at t h at is r equir ed f or all MAC im plem ent at ion s, plus sever al ad dit ional op t ional f orm at s t hat are used t o ex t end t he pr ot ocol' s basic capabilit y . The basic dat a fr am e for m at cont ain s t he sev en f ields show n in Figur e 8- 6 .

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  St a rt - of- fr am e de li m it e r ( SOF) t he DA, SA, Len gt h/ Ty pe, an d Dat a f ield s.

  

Figu r e 8 - 6 . The Ba si c I EEE 8 0 2 . 3 M AC Da t a Fr am e For m at

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

NO TE

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age I ndiv idual addr esses ar e also k now n as un icast ad dr esses because t hey r efer t o a Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . single MAC and ar e assig ned by t he NI C m anu fact ur er fr om a block of addr esses allocat ed by t he I EEE. Gr oup ad dr esses ( a.k . a. m ult icast ad dr esses) ident ify t he end

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  st at ions in a w or k gr oup and ar e assig ned b y t he n et wor k m an ager. A special gr oup enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing add ress ( all 1 s—t he br oadcast ad dr ess) in dicat es all st at ions on t he n et wor k . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Frame Transmission

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e Whenev er an en d st at ion MAC r eceives a t ran sm it - f r ame requ est wit h t h e accom pan yin g ad dr ess har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on and dat a inf orm at ion fr om t he LLC su blayer , t h e MAC begins t he t r ansm ission sequ en ce by a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t r ansfer r in g t he LLC in for m at ion in t o t h e MAC fr am e bu ff er . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich The p r eam ble an d st ar t - of - fr am e delim it er ar e inser t ed in t he PRE and SOF f ields. pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient

  The d est inat ion an d sour ce add resses ar e in ser t ed int o t he addr ess field s. decisions for t h eir net w ork s.

  The LLC dat a by t es ar e count ed, and t he n um ber of by t es is insert ed int o t he Len gt h/ Ty pe field.

  An FCS v alue is g en er at ed over t h e DA, SA, Len gt h / Typ e, and Dat a field s and is app en ded t o t he end of t he Dat a f ield . Aft er t he f ram e is assem b led, act ual f ram e t r an sm ission w ill depend on w het her t he MAC is oper at ing in h alf- d uplex or f ull- dup lex m ode. The I EEE 802 .3 st and ard cur r ent ly r eq uir es t hat all Et her net MACs sup por t h alf - du plex oper at ion, in w hich t he MAC can be eit her t r ansm it t ing or r eceiving a fr am e, but it cann ot b e

  • Table of Content s

  doing b ot h sim ult aneously . Full- dup lex op er at ion is an opt ional MAC cap abilit y t hat allow s t he

  I ndex • MAC t o t ran sm it and r eceiv e f r ames sim ult aneously.

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. Half-Duplex Transmission—The CSMA/CD Access Method

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  The CSMA/ CD pr ot ocol w as or iginally d ev elop ed as a m ean s by w h ich t w o or mor e st at ions cou ld

  I SBN: 1- 58 705 -1 19 -2

  shar e a com m on media in a swit ch- less env ir on ment w hen t he p rot ocol d oes not requ ir e cent r al

  Pages: 11 28

  ar bit r at ion, access t okens, or assigned t im e slot s t o ind icat e wh en a st at ion w ill b e allow ed t o t r ansm it . Each Et h er net MAC det er m ines for it self w hen it w ill be allow ed t o sen d a fr am e. The CSMA/ CD access r ules ar e su m mar ized b y t he pr ot ocol' s acr ony m: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  Car ri er sen se — Each st at ion cont inu ously list ens f or t r af fic on t he m edium t o d et er m in e essent ial an d cu t t ing- edg e t ech nologies.

  w hen gaps bet w een fr am e t r ansm issions occur .

  Mu lt i pl e access

  — St at ions m ay begin t r ansm it t ing any t im e t h ey det ect t hat t he n et w or k Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom is qu iet ( t her e is no t r aff ic) . nov ice t o ex pert .

  Coll ision de t e ct — I f t w o or m or e st at ions in t he sam e CSMA/ CD n et wor k ( collision

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP dom ain) begin t r ansm it t in g at app r oxim at ely t he sam e t im e, t he b it st r eam s f r om t he t r ansm it t ing st at ions w ill int er fer e ( collide) w it h each ot her, and bot h t r ansm issions w ill b e Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age un readab le. I f t h at h appens, each t ran sm it t ing st at ion m ust b e cap able of det ect ing t hat a collision has occur red befor e it has f inish ed sending it s f r ame. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Each m ust st op t r ansm it t ing as soon as it has det ect ed t he collision and t hen m ust w ait a

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  qu asir and om len gt h of t im e ( det erm ined by a back - off algor it hm ) befor e at t em pt ing t o enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing r et ran sm it t he f ram e. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  The w or st - case sit u at ion occur s w hen t he t wo m ost - dist ant st at ion s on t he n et w or k bot h n eed t o Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, sen d a fr am e an d w h en t he second st at ion d oes not begin t ran sm it t ing u nt il j ust b ef or e t he and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all fr am e f rom t he f irst st at ion ar r ives. The collision w ill be d et ect ed alm ost im m ediat ely by t h e net w or kin g p rof essionals, r egar dless of ex pert ise. second st at ion, but it w ill n ot be det ect ed by t h e fir st st at ion unt il t he cor r upt ed sig nal h as pr opag at ed all t he w ay back t o t hat st at ion. Th e m axim um t ime t hat is requ ir ed t o d et ect a Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e collision ( t he collision w indow , or " slot t im e" ) is app rox im at ely eq ual t o t w ice t he signal har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on pr opag at ion t im e b et ween t he t w o most - d ist an t st at ions on t he net w or k. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  This m eans t h at b ot h t he m inim um f r ame leng t h and t he m ax im um collision diam et er ar e Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy dir ect ly r elat ed t o t he slot t ime. Longer m inim um fr am e len gt hs t ran slat e t o long er slot t imes syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich and lar ger collision diam et er s; shor t er m inimu m f ram e lengt hs cor respond t o sh or t er slot t im es pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease and sm aller collision diam et er s. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  The t rad e- of f w as bet w een t h e need t o r ed uce t he im pact of collision r ecov ery and t he n eed for net w or k diam et er s t o be lar ge enou gh t o accom m odat e r eason able net w or k sizes. The com pr omise w as t o choose a m ax imu m net w or k diam et er ( about 250 0 met er s) and t hen t o set t he min im u m fr am e lengt h long enoug h t o ensur e det ect ion of all w or st - case collision s. dev elop er s. Fast Et h er net w as r eq uir ed t o pr ovid e backw ar d comp at ibilit y w it h ear lier Et her net net w or ks, in clud ing t he ex ist in g I EEE 802 .3 f ram e f or mat and er ror - det ect ion p rocedu res, plus all app licat ions and net w or king soft war e r un ning on t he 1 0- Mb ps net w or k s. Alt hou gh sig nal p rop agat ion velocit y is essent ially con st ant f or all t r an sm ission r at es, t he t im e r eq uir ed t o t r ansmit a f r ame is in ver sely r elat ed t o t he t ran sm ission r at e. At 1 00 Mbp s, a m inim um - len gt h fr am e can be t r ansm it t ed in app rox im at ely one- t en t h of t he d ef ined slot t im e, and any collision t h at occur r ed du rin g t h e t r ansm ission wou ld n ot lik ely b e det ect ed by t he

  • Table of Content s

  t r ansm it t ing st at ions. This, in t ur n, m eant t hat t he max im um n et w or k diam et ers sp ecified for

  I ndex •

  10 - Mbp s net w or ks could not be u sed for 100 - Mbp s net w or ks. Th e solu t ion f or Fast Et hern et w as

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  t o redu ce t he m ax im u m net w or k diam et er b y app rox im at ely a fact or of 1 0 ( t o a lit t le mor e t han By Cisco Systems, Inc. 20 0 m et ers) .

  The sam e pr ob lem also ar ose du rin g specificat ion d ev elopm en t f or Gig abit Et hern et , bu t

  Pub lish er: Cisco Press

  decreasing net w or k diam et er s by anot her f act or of 10 ( t o appr ox imat ely 20 m et ers) for 1 000 -

  Pub Dat e: Sep tem ber 1 1, 2 003

  Mb ps oper at ion was sim ply n ot p ract ical. This t im e, t he developers elect ed t o m ain t ain

  I SBN: 1- 58 705 -1 19 -2

  app rox im at ely t he sam e m axim um collision dom ain diam et er s as 1 00- Mbps net w ork s an d t o

  Pages: 11 28

  incr ease t h e appar ent m in imu m fr am e size by ad ding a var iable- len gt h nond at a ex t ension f ield t o fr am es t hat are sh ort er t h an t he m inim um leng t h ( t he ext en sion field is rem ov ed du rin g f r ame r ecept ion) .

  Figur e 8- 7 sh ows t he MAC f ram e f or mat w it h t he g ig abit ex t ension f ield, and Table 8 - 1 sh ows

  t he ef fect of t h e t r ade- off b et w een t h e t r ansm ission dat a rat e and t he m inim um f r am e size f or The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of 10 - Mbp s, 100 - Mbps, an d 100 0- Mbp s Et h er net . essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

  

Figu r e 8 - 7 . M AC Fr am e w it h Giga bi t Car r i er Ext en si on

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

Tab le 8 -1 . Li m it s f or Ha lf -D up le x Ope r a t ion

  har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  P ar am e t er 1 0 M bps 1 0 0 M bps 1 0 0 0 Mbp s [ 1]

  Minim um fr am e size 64 by t es 64 by t es 52 0 b yt es ( wit h ex t en sion field added) Max im um collision diam et er , DTE 10 0 m et ers 10 0 m et ers 10 0 m et ers UTP t o DTE UTP UTP

  31 6 m et ers fiber

  • Table of Content s

  41 2 m et ers

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ndex

  fib er

  Max im um collision diam et er w it h 25 00 m et er s 20 5 m et ers 20 0 m et ers By Cisco Systems, Inc. r ep eat er s Max im um nu m ber of r ep eat er s in

  5

  2

  1 Pub lish er: Cisco Press net w or k pat h

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 [ 1] Pages: 11 28

520 bytes applies to 100 0Base- T implem entations. The m inim um fr am e size w ith ex tension field for

1000Base- X is redu ced to 416 bytes becau se 1000Base-X encodes and tr ansm its 10 bits for each by te.

  Anot h er ch ange t o t h e Et her net CSMA/ CD t r ansm it specif icat ion w as t h e add it ion of f ram e bu rst ing f or gigab it oper at ion. Bu r st m ode is a feat ur e t h at allow s a MAC t o sen d a shor t seq uence ( a b ur st ) of f ram es equal t o ap pr oxim at ely 5. 4 m axim um - lengt h f ram es w it hou t The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of hav ing t o relinqu ish cont r ol of t h e m ed iu m . The t r an sm it t ing MAC fills each in t er f ram e int er v al essent ial an d cu t t ing- edg e t ech nologies. w it h ex t ension b it s, as show n in Figur e 8- 8 , so t hat ot her st at ions on t he net w ork will see t hat t he net w ork is busy and w ill not at t em pt t r ansmission u nt il af t er t he b ur st is com plet e.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  

Figu r e 8 - 8 . A Giga bi t Fr am e - Bur st Se qu en ce

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e I f t he lengt h of t h e fir st f r ame is less t han t h e m inimu m f ram e lengt h, an ext ension field is ad ded har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on t o ex t end t he f r am e len gt h t o t h e v alu e indicat ed in Table 8 - 1 . Su bseq uent fr am es in a fr am e- a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions bu rst sequ en ce do n ot n eed ext ension fields, and a f r ame bur st m ay cont in ue as long as t he t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . bu rst lim it has not been reached. I f t he bur st lim it is r each ed af t er a f r ame t ran sm ission has Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy begu n, t r ansm ission is allowed t o con t inue u nt il t h at ent ir e f ram e h as been sent . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Fram e ex t ension f ields are not d ef ined, an d b ur st m ode is not allow ed f or 1 0 Mbps an d 1 00 Mbp s pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient t r ansm ission rat es. decisions for t h eir net w ork s.

  Full-Duplex Transmission—An Optional Approach to Higher Network Efficiency t r ansm ission over p oin t - t o- poin t link s. Full du plex t r ansmission is f unct ionally m uch simp ler t han half - dup lex t r an sm ission because it in volv es no m edia con t en t ion, n o collisions, no need t o sch ed ule r et ran sm ission s, and no need f or ex t ension bit s on t he en d of shor t fr am es. Th e r esult is not only m or e t im e av ailab le for t r an sm ission, but also an effect iv e doub lin g of t he link ban dw idt h because each link can now sup por t f ull- r at e, sim u lt an eou s, t w o- w ay t r ansm ission. Tr ansm ission can usually b eg in as soon as f ram es ar e r ead y t o send . The on ly rest r ict ion is t hat t her e m ust b e a m inim um - lengt h int er f ram e g ap b et w een su ccessiv e fr am es, as sh ow n in Figur e

  • Table of Content s 8- 9 , an d each fr am e m ust conf or m t o Et her net f ram e f or mat st and ard s.

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 8 - 9 . Fu ll Du pl ex O pe r at ion Al low s Si m ul t a ne ous Tw o-W a y

Pub lish er: Cisco Press

  

Tr an sm issi on on t he Sam e Li nk

Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Flow Control

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Full- dup lex op er at ion r eq uir es con cu rr ent imp lem ent at ion of t he op t ional f low - con t r ol capabilit y

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age t hat allow s a r eceiv in g node ( su ch as a net w ork sw it ch por t ) t hat is becom ing congest ed t o r eq uest t h e send ing node ( su ch as a file serv er) t o st op sending f ram es f or a select ed sh ort Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . per iod of t im e. Con t r ol is MAC- t o- MAC t hr ough t h e use of a p ause fr am e t h at is au t omat ically

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  gener at ed b y t he r eceiv ing MAC. I f t h e congest ion is r eliev ed b ef or e t he r equest ed w ait has enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing exp ired, a second p ause fr am e w it h a zer o t im e- t o- w ait v alue can be sent t o r eq uest r esu mp t ion t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing of t r ansm ission. An ov erv iew of t he f low cont r ol op er at ion is show n in Figur e 8- 1 0 . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

Figu r e 8 - 1 0 . A n Ov er v ie w of t he I EEE 8 0 2 . 3 Flow Con t r ol Sequ en ce

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The f ull- du plex operat ion an d it s com pan ion f low cont r ol capab ilit y ar e b ot h opt ions f or all Et h er n et MACs an d all t r ansmission r at es. Bot h opt ions are en abled on a link - b y- link b asis, assu m in g t hat t he associat ed phy sical layer s ar e also capable of supp or t ing full- d uplex The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of oper at ion. essent ial an d cu t t ing- edg e t ech nologies.

  Pause f ram es ar e ident if ied as MAC cont r ol f r ames b y an ex clu siv e assig ned ( reser v ed) lengt h / t yp e v alu e. They ar e also assign ed a r eserv ed dest in at ion ad dr ess v alue t o ensur e t hat an Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom incom ing pause f ram e is n ev er for w ar ded t o u pper pr ot ocol lay ers or t o ot her por t s in a sw it ch. nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

Frame Reception

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Fram e r ecep t ion is essent ially t h e same for b ot h half- d uplex and fu ll- dup lex op er at ions, ex cept Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . t hat f ull- dup lex MACs m ust h ave separ at e f ram e b uf fers and dat a pat hs t o allow f or simu lt aneous f ram e t r an sm ission and r ecept ion .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Fram e r ecep t ion is t h e r ev er se of f r ame t ran sm ission . The d est inat ion ad dr ess of t h e r eceiv ed t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing fr am e is checked and m at ched ag ainst t h e st at ion's addr ess list ( it s MAC addr ess, it s gr oup indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . add resses, an d t h e br oadcast ad dr ess) t o det er min e w het her t he fr am e is dest in ed f or t hat Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, st at ion. I f an add ress m at ch is f oun d, t h e fr am e len gt h is check ed and t he r eceiv ed FCS is and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all com par ed t o t he FCS t hat w as gener at ed du r in g fr am e recept ion. I f t h e fr am e len gt h is ok ay and net w or kin g p rof essionals, r egar dless of ex pert ise. t her e is an FCS m at ch, t he f ram e t y pe is det er m ined by t h e con t ent s of t h e Lengt h/ Ty pe f ield. The f r am e is t hen par sed and f orw ar ded t o t h e app rop riat e upper lay er. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

The VLAN Tagging Option

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

  VLAN t aggin g is a MAC opt ion t hat pr ov ides t hr ee imp or t ant cap abilit ies n ot p rev iou sly available pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease t o Et her net n et wor k u ser s and net w or k m anager s: pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Pr ovid es a m ean s t o ex pedit e t im e- crit ical n et w or k t r aff ic by set t ing t r ansm ission pr iorit ies for out goin g f r ames. for w ar d VLAN f r ames on ly t o p ort s t hat ser ve t he VLAN t o wh ich t h e t r aff ic belon gs. Sim plifies net w or k m anagem en t an d m ak es adds, m ov es, and ch anges easier t o adm inist er.

  A VLAN- t agged fr am e is sim ply a b asic MAC d at a f r ame t hat has had a 4- by t e VLAN header insert ed bet w een t h e SA and Len gt h/ Ty pe field s, as show n in Figur e 8- 1 1 .

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  

Figu r e 8 - 1 1 . VLAN- Ta gge d Fr am e s Ar e I de nt if ie d W h en t he M A C Fi nds

By Cisco Systems, Inc.

t h e LA N Ty pe Va lu e in t he N or m a l Le ngt h/ Ty pe Fi el d Locat ion

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The VLAN header consist s of t w o f ield s:

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom A r eser v ed 2 - by t e t y pe v alue, indicat ing t h at t h e fr am e is a VLAN f ram e nov ice t o ex pert .

  A t wo- by t e Tag- Con t r ol field t hat con t ains b ot h t he t r ansm ission pr iorit y ( 0 t o 7, wh er e 7 is New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP t he highest ) an d a VLAN I D t h at ident if ies t he p art icular VLAN ov er w hich t h e fr am e is t o be Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age sen t The r eceiv ing MAC reads t he r eser v ed t y pe v alue, w hich is locat ed in t he nor m al Len gt h/ Typ e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . field posit ion , and int er pr et s t he receiv ed f r ame as a VLAN fr am e. Then t he f ollowin g occur s:

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing I f t he MAC is inst alled in a sw it ch por t , t h e fr am e is for w ar ded accor ding t o it s pr ior it y lev el t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing t o all por t s t h at ar e associat ed w it h t h e indicat ed VLAN ident if ier . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  I f t he MAC is inst alled in an end st at ion , it rem oves t h e 4- b yt e VLAN h ead er and pr ocesses and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t he fr am e in t he sam e m anner as a basic dat a fr am e. net w or kin g p rof essionals, r egar dless of ex pert ise.

  VLAN t aggin g r equir es t hat all net w or k nod es in volv ed w it h a VLAN g rou p b e equipp ed w it h t he Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e VLAN opt ion. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

The Ethernet Physical Layers

  Becau se Et her net d ev ices im plem en t on ly t he b ot t om t w o lay er s of t he OSI pr ot ocol st ack, t hey ar e t y pically im plem en t ed as net w ork in t er f ace car ds ( NI Cs) t hat plug int o t he host dev ice' s m ot her boar d. Th e diff erent NI Cs ar e ident if ied by a t hr ee- par t p rod uct n ame t hat is based on t he

  • Table of Content s ph ysical layer at t rib ut es.

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  The n am in g con vent ion is a con cat enat ion of t h ree t er m s indicat ing t he t ran sm ission r at e, t he t r ansm ission met h od, and t h e m ed ia t y pe/ sig nal encodin g. For exam p le, consider t h is:

  By Cisco Systems, Inc.

  Pub lish er: Cisco Press

  10 Base- T = 10 Mb ps, baseband , ov er t wo t w ist ed - pair cables

  Pub Dat e: Sep tem ber 1 1, 2 003

  10 0Base- T2 = 100 Mb ps, baseband , over t wo t w ist ed - pair cables

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  10 0Base- T4 = 100 Mb ps, baseband , over f our - t w ist ed p air cab les 10 00Base- LX = 10 0 Mbps, baseban d, long w av elengt h ov er opt ical f iber cable A q uest ion som et im es ar ises as t o w hy t he m iddle t er m alw ay s seem s t o b e " Base. " Ear ly The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of v er sions of t h e pr ot ocol also allow ed f or br oadb and t r ansmission ( f or exam p le, 1 0Br oad) , b ut br oadb and imp lem ent at ion s w er e n ot successfu l in t he m ar ket place. All cur r en t Et hern et essent ial an d cu t t ing- edg e t ech nologies. im plem ent at ion s use baseband t r ansm ission.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

Encoding for Signal Transmission

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP I n baseb and t r ansmission, t h e fr am e inf orm at ion is dir ect ly im pr essed upon t h e lin k as a

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age seq uence of pu lses or d at a sy mb ols t hat are t yp ically at t enu at ed ( r educed in size) and d ist or t ed ( chang ed in shape) b ef or e t hey r each t h e ot her end of t he link . Th e r eceiver 's t ask is t o det ect Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . each p ulse as it ar r ives and t h en t o ex t r act it s cor r ect valu e befor e t r ansf er r ing t he r econ st ru ct ed inf orm at ion t o t he r eceiv in g MAC.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Filt er s and p ulse- shap in g cir cuit s can help r est or e t he size and shape of t h e r eceived w avef orm s, t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing bu t ad dit ional m easur es m u st be t aken t o ensur e t h at t h e r eceived sig nals ar e samp led at t he indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . corr ect t im e in t he p ulse per iod and at same rat e as t he t ran sm it clock : Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  The r eceiv e clock m u st be r ecover ed f rom t he incom ing dat a st ream t o allow t he receiv ing ph ysical layer t o syn ch ron ize w it h t he incom ing pulses. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Com pensat ing m easu res m ust be t ak en for a t r ansmission ef fect k now n as baselin e a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions w and er . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Clock r ecov ery r equ ir es level t r ansit ions in t h e incomin g sign al t o id en t ify an d sy nchr onize on Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy pu lse b ound aries. The alt er nat ing 1 s and 0s of t h e fr am e pr eam ble w ere d esign ed bot h t o syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich indicat e t h at a fr am e w as ar r iv ing and t o aid in clock recover y . How ev er, recov er ed clocks can pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease dr ift and possibly lose sy nch ron izat ion if pu lse lev els r em ain const ant and t h er e ar e no pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient t r ansit ions t o det ect ( f or ex am ple, du rin g lon g st r ings of 0s) . decisions for t h eir net w ork s. Baseline wan der r esult s becau se Et her net link s ar e AC- coup led t o t he t r an sceiv er s and because AC cou pling is incapable of m aint ain in g volt ag e lev els for m or e t h an a shor t t im e. As a result , level p asses t hr oug h t he decision t hr eshold, r esult ing in er r oneous sam pled v alues for t he aff ect ed pu lses.

  

Figu r e 8 - 1 2 . A Con ce pt Exa m ple of B asel in e W an de r

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Fort unat ely , en coding t he ou t going signal befor e t r ansm ission can signif ican t ly redu ce t he eff ect of bot h t h ese p rob lem s, as w ell as r ed uce t he possib ilit y of t r ansm ission err or s. Ear ly Et h er net

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP im plem ent at ion s, up t o an d in clu ding 10Base- T, all u sed t he Manchest er encod in g m et hod , Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age show n in Figur e 8- 1 3 . Each pu lse is clear ly id en t ified b y t he direct ion of t he m idpu lse t ran sit ion r at her t h an b y it s sam pled level v alue.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

Figu r e 8 - 1 3 . Tr a nsit ion- Ba se d M an che st e r Bi na r y Encodi ng

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. Unfor t u nat ely, Manchest er en cod in g in t r oduces some d iff icult fr equency - r elat ed pr oblem s t hat m ake it un su it able f or use at higher d at a r at es. Et h er net ver sion s su bsequent t o 1 0Base- T all use dif fer en t encoding pr ocedur es t hat include som e or all of t he f ollow ing t echniqu es:

  ( and r ecov erab le) m anner . Som e 0s ar e chan ged t o 1s, som e 1s are ch anged t o 0 s, and som e bit s ar e left t he sam e. The r esu lt is r educed r u n- len gt h of sam e- v alue b it s, in cr eased t r ansit ion densit y, an d easier clock r ecov ery .

  Ex pa ndi ng t he code spa ce

  — A t echniqu e t hat allows assign ment of sep arat e cod es for dat a and cont r ol sy mb ols ( such as st art - of - st r eam and en d- of - st ream d elim it er s, ext en sion bit s, an d so on) an d t hat assist s in t ran smission er ror det ect ion.

  • Table of Content s

  U si ng for w a rd e rr or- corr ect i ng cod es

  — An encodin g in w hich redu ndan t inf or mat ion is

  I ndex •

  add ed t o t he t r an sm it t ed dat a st r eam so t h at som e t y pes of t r ansm ission er r or s can b e

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion corr ect ed d ur in g fr am e r ecept ion.

  By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

NO TE

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Forw ar d err or - corr ect ing cod es are u sed in 100 0Base- T t o achiev e an ef fect ive r ed uct ion in t h e bit er r or r at e. Et h er net pr ot ocol limit s er r or han dling t o d et ect ion of bit err or s in t he r eceiv ed f ram e. Recov er y of f ram es r eceived w it h uncor rect able er ror s or m issing f ram es is t he responsibilit y of hig her layer s in t he pr ot ocol st ack .

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

The 802.3 Physical Layer Relationship to the ISO Reference Model

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Alt hou gh t he specific logical m odel of t h e phy sical layer m ay v ar y fr om v ersion t o v ersion, all nov ice t o ex pert . Et h er n et NI Cs gener ally con for m t o t he g en er ic m odel show n in Figur e 8- 1 4 .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  

Figu r e 8 - 1 4 . Th e Gen er i c Et he r ne t Phy si cal Lay er Re fe r e nce M od el

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The p hy sical lay er for each t r ansmission r at e is d ivided int o su blay er s t h at ar e ind ep en dent of t he par t icu lar m ed ia t y pe and sub lay er s t hat ar e sp ecif ic t o t h e m ed ia t y pe or sign al encoding.

  The r econciliat ion sublay er and t he op t ional m edia- ind ep en dent in t er f ace ( MI I in 10- Mb ps and 10 0- Mb ps Et hern et , GMI I in Gigab it Et h er n et ) pr ov ide t he log ical con nect ion bet w een t he MAC and t he d if fer en t set s of m edia- dependent lay er s. The MI I and GMI I ar e def in ed w it h separ at e t ran sm it and receiv e d at a pat hs t h at ar e bit - ser ial for 1 0- Mb ps im plem ent at ion s, nibble- ser ial ( 4 b it s w id e) f or 100 - Mbp s imp lem ent at ion s, and by t e- ser ial ( 8 bit s w ide) for 1 000 - Mbp s imp lem ent at ions. Th e m ed ia- in dependent int er faces and t he r econciliat ion su blayer ar e com m on f or t heir r esp ect iv e t r ansm ission rat es an d ar e conf ig ur ed f or fu ll- duplex oper at ion in 1 0Base- T and all sub sequ en t Et hern et v er sions. The m edia- d ep en dent p hy sical codin g sub layer ( PCS) pr ov ides t he log ic for encodin g, m ult iplexin g, an d sy nchr onizat ion of t he ou t going sym b ol st r eam s as w ell sy mb ol code alignm ent , demu lt ip lex ing, and decoding of t he in com ing dat a. The p hy sical m edium at t achm en t ( PMA) sublay er cont ains t he signal t ran sm it t er s and r eceiver s ( t r ansceiv ers) , as w ell as t he clock recover y logic f or t he receiv ed d at a st r eams.

  The m edium - d ep en dent in t erf ace ( MDI ) is t he cable conn ect or b et w een t he signal t r ansceiv ers an d t he link . The Au t o- negot iat ion sublay er allow s t he NI Cs at each end of t he link t o ex ch ange inf orm at ion abou t t h eir in divid ual capab ilit ies, and t hen t o n eg ot iat e and select t h e m ost Depend in g on w h ich t y pe of signal en cod ing is used an d h ow t he lin ks ar e conf igur ed, t he PCS and PMA m ay or m ay not be capab le of su ppor t ing f ull- dup lex op er at ion.

  10 Base- T pr ovides Manchest er - encoded 1 0- Mb ps b it - ser ial comm u nicat ion ov er t w o u nshield ed

  Table of Content s •

  t w ist ed - pair cables. Alt houg h t he st andar d w as designed t o sup por t t ran sm ission ov er com m on

  I ndex •

  t elep hone cable, t h e m ore t yp ical lin k con figu r at ion is t o use t w o pair of a f our - pair Cat egor y 3

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  or 5 cable, t erm inat ed at each NI C w it h an 8- pin RJ- 4 5 con nect or ( t he MDI ) , as show n in Figur e

  By 8- 1 5 Cisco Systems, Inc. . Because each act ive pair is conf ig ur ed as a sim p lex link w h er e t r ansm ission is in one

  dir ect ion only , t h e 10Base- T p hy sical lay er s can supp ort eit her half - dup lex or f ull- du plex oper at ion.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 8 - 1 5 . Th e Ty pi cal 1 0 B ase- T Link I s a Four - Pa ir U TP Ca ble i n

W hi ch Tw o Pai r s Ar e N ot U se d

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Alt hou gh 10Base- T m ay b e con sid er ed essen t ially ob solet e in some cir cles, it is in clu ded h er e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease because t her e ar e st ill m any 10 Base- T Et her net n et w or k s, and because fu ll- d uplex oper at ion has pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient giv en 1 0BaseT an ex t ended life. decisions for t h eir net w ork s.

  10 Base- T was also t he f irst Et her net v er sion t o in clu de a lin k int egr it y t est t o det er m ine t h e healt h of t he link . I m m ed iat ely af t er pow eru p, t h e PMA t ran smit s a nor m al link p ulse ( NLP) t o t ell t he NI C at t he ot h er en d of t h e link t h at t h is NI C w ant s t o est ablish an act ive lin k con nect ion :

  I f t he NI C at t h e ot her end of t h e lin k is also pow er ed up , it r espond s w it h it s own NLP. I f t he NI C at t h e ot her end of t h e lin k is not pow ered up , t his NI C con t inues sending an NLP abou t on ce ev er y 1 6 ms unt il it r eceives a response.

  The link is act iv at ed only aft er b ot h NI Cs ar e capable of exch anging v alid NLPs.

  Table of Content s • 100 Mbps—Fast Ethernet

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ncr easing t he Et her net t r an sm ission r at e by a fact or of t en ov er 10Base- T w as n ot a sim ple By Cisco Systems, Inc. t ask , and t he ef for t result ed in t h e developm ent of t hr ee separ at e p hy sical lay er st andar ds f or 10 0 Mbps ov er UTP cable: 1 00Base- TX and 1 00Base- T4 in 19 95, and 100 Base- T2 in 199 7. Each

  Pub lish er: Cisco Press

  w as def in ed w it h diff erent encoding r eq uir em ent s an d a dif fer en t set of m edia- depend en t

  Pub Dat e: Sep tem ber 1 1, 2 003

  sublay ers, ev en t h ough t her e is som e over lap in t h e lin k cabling. Table 8 - 2 com par es t he

  I SBN: 1- 58 705 -1 19 -2 ph ysical layer char act erist ics of 10Base- T t o t he var ious 1 00Base v ersions. Pages: 11 28

  

Tab le 8 -2 . Sum m a r y of 1 0 0 Ba se - T Phy sica l Lay e r Cha r act er i st ics

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Et he rn et Tra nsm it Sy m b ol Full - D up le x [ 1 ] V e rsion Ra t e Encodi ng Cab lin g Ope r at i on

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  10 Base- T

  10 MBd Man ch est er Tw o p airs of UTP Cat egor y Sup por t ed nov ice t o ex pert .

  • –3 or b et t er 10 0Base- TX 12 5 MBd

  4B/ 5 B Tw o p airs of UTP Cat egor y Sup por t ed New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  • –5 or Ty pe 1 STP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 10 0Base- T4

  33 MBd

  8B/ 6 T Four p air s of UTP Cat eg or y Not su ppor t ed

  • –3 or b et t er Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  10 0Base- T2

  25 MBd PAM5x 5 Tw o p airs of UTP Cat egor y Sup por t ed

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  • –3 or b et t er enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . [ 1]

  On e baud = one tr ansm itted sym bol per second, w her e th e tr ansmit ted sy mbol may contain the equivalent

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, value of 1 or mor e binar y bits. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  Alt hou gh not all t hr ee 100 - Mbp s v er sions w ere su ccessf ul in t he mar k et place, all t hr ee hav e been d iscussed in t he lit er at ur e, and all t h ree d id im pact fut u r e desig ns. As such, all t hr ee are Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e im por t ant t o consider h er e. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  100Base-X

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich 10 0Base- X w as desig ned t o sup por t t r ansm ission ov er eit her t w o pair s of Cat egor y 5 UTP copper pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease w ire or t w o st r and s of opt ical f ib er . Alt h ough t h e en cod ing, decod in g, an d clock r ecov er y pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient pr oced ur es ar e t he sam e for bot h m ed ia, t he sign al t r ansm ission is diff er ent —elect r ical pu lses in decisions for t h eir net w ork s. copper an d ligh t p ulses in opt ical f iber. The signal t r ansceiv er s t h at w er e inclu ded as par t of t he PMA fun ct ion in t he g en er ic logical m odel of Figur e 8- 1 4 w er e r ed ef ined as t he separ at e ph ysical m ed ia- dependent ( PMD) sublay ers sh own in Figur e 8- 1 6 .

  

Figu r e 8 - 1 6 . Th e 1 0 0 Ba se - X Log ica l M odel

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  The 1 00Base- X encodin g p rocedur e is b ased on t he ear lier FDD I opt ical f ib er phy sical media- enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing depend en t an d FDD I / CDDI copp er t w ist ed- p air phy sical m ed ia- d ep en dent sig naling st andar ds t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing dev elop ed by I SO and ANSI . The 1 00Base- TX p hy sical m edia- depend en t sublay er ( TP- PMD ) w as indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . im plem ent ed w it h CDDI sem icon duct or t r an sceiv er s and RJ- 4 5 con nect or s; t he fib er PMD w as Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, im plem ent ed w it h FDD I opt ical t r ansceiv er s and t he Low Cost Fib re I n t er f ace Connect or and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all ( com mon ly called t he d uplex SC con nect or ) . net w or kin g p rof essionals, r egar dless of ex pert ise.

  The 4 B/ 5B en cod in g pr ocedu re is t he sam e as t h e en cod ing pr oced ur e used b y FD DI , w it h only Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e m inor ad apt at ions t o accom m odat e Et her net f r am e con t r ol. Each 4- bit dat a nibble ( repr esent in g har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on half of a dat a b yt e) is m apped int o a 5- b it b in ary cod e- g rou p t hat is t r ansmit t ed bit - serial over a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t he lin k. The exp anded code space pr ov ided b y t he 3 2 5- bit cod e- gr oups allow separ at e t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . assig nm en t f or t he follow ing: Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease The 1 6 possib le values in a 4 - bit dat a n ibble ( 1 6 code- g rou ps) . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Four cont r ol cod e- g rou ps t h at ar e t r ansm it t ed as cod e- g r oup pair s t o in dicat e t he st ar t - of - st r eam delim it er ( SSD) and t he end - of- st r eam delimit er ( ESD) . Each MAC f ram e is " encapsulat ed" t o m ar k bot h t h e beginn in g and en d of t he f ram e. The fir st by t e of p ream ble is r ep laced w it h SSD code- gr oup pair t hat pr ecisely ident if ies t he f ram e's cod e- g r oup

  A special I DLE code- gr oup t h at is cont in uously sen t d ur ing in t erf r ame gaps t o m aint ain cont inu ous sy nchr onizat ion bet w een t he NI Cs at each end of t h e lin k. The r eceipt of I D LE is int er pr et ed t o mean t hat t he lin k is quiet . Elev en inv alid code- gr ou ps t hat ar e not int ent ionally t r an sm it t ed by a NI C ( alt hou gh one is used by a r epeat er t o pr opagat e receiv e er ror s) . Receip t of an y inv alid code- gr oup w ill cause t he in com ing f ram e t o be t reat ed as an in valid fr am e.

  • Table of Content s

  Figur e 8- 1 7 sh ows how a MAC fr am e is encapsulat ed b ef or e being t r ansm it t ed as a 100 Base- X

  • I ndex code- gr oup st r eam .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Figu r e 8 - 1 7 . Th e 1 0 0 Ba se - X Code- Gr ou p St r e am w i t h Fr am e Pub Dat e: Sep tem ber 1 1, 2 003 Encapsu la t ion

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

[ View full size im age]

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 10 0Base- TX t r ansm it s and r eceives on t he sam e link p air s an d uses t he sam e pin assign ment s on t he MDI as 1 0Base- T. 100 Base- TX an d 100 Base- FX bot h sup por t h alf- du plex and fu ll- d uplex Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . t r ansm ission.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  100Base-T4 indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, 10 0Base- T4 w as d ev elop ed t o allow 10 BaseT n et wor k s t o be up gr aded t o 1 00- Mb ps op er at ion and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all w it hout r equir ing ex ist ing fou r- p air Cat egor y 3 UTP cables t o b e r ep laced wit h t h e new er net w or kin g p rof essionals, r egar dless of ex pert ise. Cat egor y 5 cables. Tw o of t he four pair s ar e con figu red for half- d uplex oper at ion and can supp ort t r ansm ission in eit her d ir ect ion , bu t on ly in on e dir ect ion at a t im e. The ot h er t wo pair s Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e ar e config ur ed as sim plex pair s dedicat ed t o t r ansm ission in on e dir ect ion only . Fram e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on t r ansm ission uses bot h half- duplex pair s, plu s t he sim plex pair t h at is ap pr opr iat e for t he a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t r ansm ission dir ect ion, as sh ow n in Figur e 8- 1 8 . Th e sim plex pair for t h e opposit e d ir ect ion t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . pr ov ides carr ier sen se an d collision det ect ion. Full- du plex operat ion cannot be su ppor t ed on Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy 10 0Base- T4 . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  

Figu r e 8 - 1 8 . Th e 1 0 0 Ba se - T4 W i r e- Pa ir U sa ge Du r in g Fr a m e

Tr an sm issi on

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 10 0Base- T4 u ses an 8B6 T encoding sch em e in w hich each 8- b it binar y b yt e is map ped in t o a nov ice t o ex pert . pat t er n of six t er nar y ( t h r ee- level: + 1, 0, – 1) sy m bols k now n as 6T code- gr oups. Separ at e 6 T code- gr oup s are used f or I DLE and f or t he con t rol cod e- gr oups t hat ar e n ecessar y f or fr am e

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP t r ansm ission. I DLE receiv ed on t h e dedicat ed r eceiv e pair ind icat es t h at t h e link is qu iet . Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Du ring f r ame t ran sm ission , 6T dat a cod e- g r oups ar e t r ansm it t ed in a delayed rou nd- r ob in seq uence ov er t he t h ree t r ansm it w ir e– pair s, as show n in Figur e 8- 1 9 . Each f ram e is Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . encapsulat ed wit h st ar t - of- st r eam and end - of- pack et 6T code- gr oups t hat m ark b ot h t he beginn ing and end of t he f ram e, an d t h e beginn ing and end of t he 6 T code- gr oup st r eam on

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  each w ir e pair . Receip t of a non- I DLE cod e- g rou p ov er t h e dedicat ed r eceiv e- p air any t im e enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing befor e t he collision win dow ex pir es in dicat es t hat a collision has occur red. t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all

Figu r e 8 - 1 9 . Th e 1 0 0 Ba se - T4 Fr a m e Tr a n sm i ssion Sequ en ce net w or kin g p rof essionals, r egar dless of ex pert ise

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  100Base-T2

  The 1 00Base- T2 sp ecificat ion w as dev eloped as a bet t er alt er nat iv e f or up gr ading net w or ks wit h inst alled Cat eg ory 3 cabling t h an w as b ein g p rov ided by 1 00Base- T4. Tw o im p ort an t n ew goals

  • I ndex •

  Table of Content s

  w ere d ef ined:

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  To p r ovide com m un icat ion ov er t wo pair s of Cat egor y 3 or b et t er cab le By Cisco Systems, Inc. To su ppor t bot h half- d uplex and f ull- dup lex op er at ion

  Pub lish er: Cisco Press

  10 0Base- T2 u ses a diff er ent sig nal t r ansm ission pr oced ur e t han an y pr ev ious t wist ed- p air

  Pub Dat e: Sep tem ber 1 1, 2 003

  Et h er n et imp lem ent at ions. I n st ead of using t w o sim plex lin ks t o f orm one f ull- dup lex link , t h e

  I SBN: 1- 58 705 -1 19 -2

  10 0Base- T2 d ual- dup lex b aseban d t ran sm ission m et hod sen ds encoded sy m bols sim ult aneously

  Pages: 11 28

  in bot h dir ect ions on b ot h w ir e p airs, as sh own in Figur e 8- 2 0 . Th e t erm " TDX< 3: 2> " indicat es t he 2 m ost sign ificant bit s in t he n ib ble bef ore encodin g an d t ran sm ission . " RD X< 3 : 2> " in dicat es t he sam e 2 bit s aft er r eceipt and decoding.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  

Figu r e 8 - 2 0 . Th e 1 0 0 Ba se - T2 Lin k Topology

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Du al- d uplex baseband t r ansm ission r eq uir es t he NI Cs at each end of t he link t o be operat ed in a on t he m ast er NI C's in t ern al t r ansm it clock . Th e slav e NI C uses t he r ecov er ed clock f or bot h t r ansm it and r eceiv e oper at ions, as show n in Figur e 8- 2 1 . Each t r ansm it t ed f r ame is encapsulat ed, an d link sy nchr onizat ion is m aint ained w it h a cont inu ous st r eam of I D LE sym bols du rin g in t er f ram e g aps.

  

Figu r e 8 - 2 1 . Th e 1 0 0 Ba se - T2 Loop Tim i ng Con f igu r at ion

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  The 1 00Base- T2 en cod ing pr ocess f ir st scr amb les t he dat a f ram e n ib bles t o r and om ize t he b it Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . seq uence. I t t h en m aps t h e t w o u pper b it s and t he t wo low er bit s of each n ib ble int o t w o f ive- level ( + 2, + 1, 0 , –1, –2) pu lse am plit u de- mod ulat ed ( PAM5) sy m bols t h at ar e sim ult aneously

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  t r ansm it t ed ov er t he t wo w ire pair s ( PAM5x 5) . Diff er ent scr am bling pr oced ur es for m ast er and enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing slave t ran sm ission s en su r e t hat t he d at a st r eams t rav elin g in op posit e dir ect ions on t h e same t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing w ire pair ar e un coor din at ed . indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Signal r ecept ion is essent ially t he r ever se of sig nal t r ansm ission. Because t h e sig nal on each w ir e and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all pair at t he MDI is t h e sum of t h e t r ansm it t ed signal and t he r eceiv ed signal, each receiv er net w or kin g p rof essionals, r egar dless of ex pert ise. subt r act s t h e t r ansm it t ed sy mb ols fr om t h e sig nal r eceiv ed at t he MDI t o recov er t he sym b ols in t he in com ing d at a st r eam . The incom ing sy m bol p air is t hen decoded, un scr am bled, an d Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e r econst it u t ed as a dat a nibb le for t r an sf er t o t h e MAC. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  1000 Mbps—Gigabit Ethernet

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich The Gigabit Et her net st an dar ds d ev elop m en t r esu lt ed in t w o pr im ar y specif icat ions: 100 0Base- T pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease for UTP copper cable and 1 000 Base- X STP copper cable, as w ell as single an d m u lt im ode opt ical pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient fib er ( see decisions for t h eir net w ork s. Figur e 8- 2 2 ) .

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  1000Base-T

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 10 00Base- T Et hern et pr ov ides fu ll- d uplex t r ansm ission over f our - pair Cat eg ory 5 or bet t er UTP nov ice t o ex pert . cable. 100 0Base- T is based lar g ely on t he find in gs an d d esign app roaches t h at led t o t h e dev elop ment of t he Fast Et her net p hy sical lay er im p lem ent at ions:

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 10 0Base- TX pr ov ed t h at bin ary sy m bol st r eams cou ld b e successf ully t r ansm it t ed ov er Cat egor y 5 UTP cable at 125 MBd . Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . 10 0Base- T4 p rov ided a basic un der st an ding of t he pr oblem s r elat ed t o sen ding m ult ilev el

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat signals ov er fou r w ire pairs.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 10 0Base- T2 p rov ed t hat PAM5 encodin g, coup led w it h digit al sign al pr ocessing, cou ld indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . han dle bot h sim ult aneous t w o- w ay d at a st r eams and pot ent ial cr osst alk pr oblem s r esult ing

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, fr om alien sig nals on adj acent w ire p airs. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  10 00Base- T scram b les each b yt e in t h e MAC fr am e t o ran dom ize t he bit sequence b ef ore it is encoded usin g a 4- D , 8- St at e Trellis Forw ar d Er r or Cor r ect ion ( FEC) cod ing in w h ich fou r PAM5 Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e sym b ols are sent at t he sam e t ime over f our w ir e pair s. Fou r of t he fiv e lev els in each PAM5 har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on sym b ol r ep resen t 2 bit s in t h e dat a by t e. The f ift h level is u sed for FEC codin g, w hich en hances a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions sym b ol r ecov er y in t he pr esence of noise and crosst alk . Sep ar at e scr am blers for t h e m ast er and t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . slave PHYs cr eat e essent ially un cor r elat ed dat a st ream s bet w een t h e t w o op posit e- t rav elling Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy sym b ol st ream s on each w ir e pair . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease The10 00Base- T link t op ology is show n in Figur e 8- 2 3 . Th e t erm " TDX< 7: 6> " indicat es t he 2 pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient m ost signif ican t bit s in t h e dat a by t e bef ore encodin g an d t ran sm ission . " RD X< 7 : 6> " in dicat es decisions for t h eir net w ork s. t he sam e 2 bit s aft er r eceipt and decoding.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient The clock r ecov er y an d m ast er / slav e loop t imin g p rocedu res ar e essent ially t he sam e as t hose decisions for t h eir net w ork s. used in 10 0Base- T2 ( see Figur e 8- 2 4 ) . Wh ich NI C will b e m ast er ( t yp ically t h e NI C in a m ult ip ort int er m ed iat e net w ork node) an d wh ich w ill be slav e is det erm ined du ring au t onegot iat ion.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  Each t r ansm it t ed f ram e is encapsulat ed w it h st ar t - of - st ream an d en d- of- st r eam delim it er s, and Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age loop t imin g is m aint ain ed by con t inuou s st ream s of I DLE sy mb ols sent on each w ir e pair du rin g int er fr am e gap s. 100 0Base- T su ppor t s bot h half- d uplex and f ull- dup lex op er at ion. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

  1000Base-X

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . All t h ree 10 00Base- X v ersions su ppor t full- du plex binar y t r ansm ission at 1 250 Mb ps ov er t w o Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, st r ands of op t ical fiber or t w o STP copp er w ir e–p air s, as show n in Figur e 8- 2 5 . Tr ansm ission and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all coding is based on t h e ANSI Fibr e Chan nel 8B/ 1 0B encod in g schem e. Each 8- bit dat a by t e is net w or kin g p rof essionals, r egar dless of ex pert ise. m apped int o a 10 - bit cod e- g r oup for b it - ser ial t r ansm ission. Like ear lier Et her net v ersions, each dat a fr am e is encapsulat ed at t h e ph ysical layer b ef ore t r ansmission , and link sy nchr onizat ion is Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e m aint ained by sending a con t inuou s st ream of I DLE cod e- g rou ps d ur in g in t erf r ame gaps. All har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on 10 00Base- X ph ysical lay er s sup por t b ot h half- d uplex and fu ll- dup lex op er at ion. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

Figu r e 8 - 2 5 . 1 0 0 0 Ba se- X Lin k Con f igu r at ion

  pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The p r in cip al dif ferences am ong t he 100 0Base- X ver sion s ar e t he link media and connect or s t hat t he par t icu lar ver sion s w ill supp ort and , in t he case of opt ical m ed ia, t he w av elen gt h of t he opt ical sign al ( see Table 8 - 3 ) . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Tab le 8 -3 . 1 0 0 0 Ba se - X Li nk Con fi gu r at i on Su ppor t New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  1 0 0 0 Ba se - S X ( 8 5 0 1 0 0 0 Ba se - LX ( 1 3 0 0 Li nk Conf ig ura t ion 1 0 0 0 Ba se - CX nm W a v el en gt h) nm W a v el en gt h)

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 15 0 W STP copper Sup por t ed Not su ppor t ed Not su ppor t ed Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . 12 5/ 62 .5 m Not su ppor t ed Sup por t ed Sup por t ed

  m I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  m ult im ode op t ical

  [ 1]

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing fib er t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing 12 5/ 50 m m m ult im ode Not su ppor t ed Sup por t ed Sup por t ed indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . opt ical f iber

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all 12 5/ 10 m single m od e Not su ppor t ed Not su ppor t ed Sup por t ed

  m net w or kin g p rof essionals, r egar dless of ex pert ise.

  opt ical f iber Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  Allow ed connect or s

  I EC st yle 1 or Fibr e SFF MT- RJ or Du plex SFF MT- RJ or Du plex har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Ch annel st y le 2 SC SC a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy [ 1] The 125/ 62.5 m specification r efer s to the cladding and cor e diameter s of the optical fiber .

  m

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient

  Network Cabling—Link Crossover Requirements decisions for t h eir net w ork s.

  Lin k com p at ib ilit y requ ires t h at t h e t r ansm it t er s at each end of t he link be connect ed t o t he r eceiver s at t he ot h er en d of t h e link . How ev er, becau se cab le con nect ors at bot h end s of t he link

  Unfor t u nat ely, wh en t h is requ irem ent f ir st came up in t h e dev elopm ent of 10Base- T, I EEE 8 02. 3 chose not t o m ak e a har d r u le as t o w h et h er t he cr ossov er sh ould be im plement ed in t he cable as show n in Figur e 8- 2 6a or w het her it shou ld b e im plem ent ed int ern ally as show n in Figur e 8- 26 b .

  • Table of Content s

  

Figu r e 8 - 2 6 . A lt e r n at i ve W a ys for I m pl em e nt in g t he Li nk Cr ossov er

  • I ndex

  

Re qu ir e m en t

I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, I nst ead, I EEE 8 02. 3 defin ed t w o ru les an d m ad e t w o r ecom m endat ion s: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  Ther e m ust b e an odd num b er of cr ossov ers in all m u lt icond uct or link s. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on

  I f a PMD is equip ped w it h an int er nal cr ossov er, it s MDI m u st be clearly labeled w it h t h e a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions gr aph ical X sym b ol. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy I m plem ent at ion of an int er nal cr ossov er fu nct ion is op t ional. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  When a D TE is con nect ed t o a r ep eat er or sw it ch ( DCE) p ort , it is r ecom m ended t hat t he pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient crossov er be im plem ent ed w it hin t he D CE por t . decisions for t h eir net w ork s. The ev ent ual result was t hat por t s in most DCEs w er e equ ip ped wit h PMD s t hat cont ained int er nal cr ossov er cir cuit r y and t h at D TEs had PMD s w it hout int er nal cr ossov ers. Th is led t o t he follow ing oft - quot ed de f act o " inst allat ion r u le" :

  Use a st r aig ht - t h rou gh cable w hen con nect in g D TE t o DCE. Use a cr ossov er cab le w hen connect ing DTE t o D TE or DCE t o DCE. Unfor t u nat ely, t he de fact o r ule d oes not apply t o all Et h er n et ver sion s t hat hav e b een developed subsequent t o 10Base- T. As t h in gs n ow st and, t he f ollow ing is t r u e:

  All f ib er - b ased syst em s use cables t hat hav e t he cr ossov er im plem ent ed w it hin t he cable.

  • Table of Content s

  I ndex

  All 10 0Base syst em s using t w ist ed - pair link s use t h e sam e r ules and r ecom m endat ion s as

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion 10 Base- T.

  By Cisco Systems, Inc.

  10 00Base- T NI Cs m ay im plem en t a select ab le int ern al cr ossov er opt ion t hat can b e negot iat ed and enabled dur ing aut on eg ot iat ion. Wh en t h e select able crossover op t ion is not

  Pub lish er: Cisco Press im plem ent ed, 10Base- T r ules and r ecom m endat ion s apply .

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

System Considerations

  Giv en all t he choices d iscussed p rev iously , it m ight seem t h at it wou ld b e no pr oblem t o upgr ad e an ex ist ing net w or k or t o plan a new n et w or k . The pr oblem is t w ofold. Not all t he choices ar e r easonab le for all net w ork s, and n ot all Et her net v er sions an d op t ions ar e av ailable in t he

  • Table of Content s m ar ket , ev en t h ough t hey m ay h ave b een specif ied in t he st and ard .
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc. Choosing UTP-Based Components and Media Category Pub lish er: Cisco Press

  By now , it should be obv iou s t hat UTP- based NI Cs ar e av ailable for 10- Mbps, 10 0- Mb ps, and

  Pub Dat e: Sep tem ber 1 1, 2 003

  10 00- Mbps im plem en t at ions. The ch oice is r elat ively simp le for b ot h 10- Mbps an d 1 000 - Mbp s

  I SBN: 1- 58 705 -1 19 -2

  oper at ion: 10Base- T and 1 000 Base- T. Fr om t he pr ev ious d iscussions, how ever , it w ould n ot

  Pages: 11 28 seem t o be t hat sim ple f or 10 0- Mbp s im plem ent at ion s.

  Alt hou gh t hr ee UTP- b ased NI Cs ar e defin ed f or 100 Mb ps, t h e m ark et h as ef fect ively nar r ow ed t he ch oice t o ju st 10 0Base- TX, w hich b ecam e w idely available d ur ing t he f irst half of 199 5: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  By t h e t ime 100 Base- T4 pr odu ct s fir st app ear ed on t h e m ar ket , 1 00Base- TX w as w ell essent ial an d cu t t ing- edg e t ech nologies. ent r enched, an d d ev elopm en t of t h e fu ll- d uplex opt ion , w hich 1 00Base- T4 cou ld n ot supp ort , w as w ell und er w ay .

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The 1 00Base- T2 st andar d w as not appr ov ed u nt il spr ing 19 97, t oo lat e t o int er est t he nov ice t o ex pert . m ar ket place. As a result , 1 00Base- T2 p r oduct s w er e not ev en m an ufact u red.

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Sever al choices hav e also been specified f or UTP m edia: Cat eg ory 3, 4 , 5, or 5E. The dif fer en ces ar e cable cost and t r ansm ission r at e capabilit y, bot h of w hich in cr ease w it h t h e cat eg or y

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age nu mb er s. How ever , cur r en t t r ansm ission r at e r eq uir em ent s an d cab le cost sh ould not be t he deciding fact or s in ch oosin g w h ich cable cat egor y t o in st all. To allow for fut ur e t r ansm ission r at e Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . needs, cables lower t han Cat egor y 5 sh ould not ev en be considered, and if gigabit r at es are a possible fu t ur e need, Cat eg or y 5E should be seriou sly consider ed :

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing I nst allat ion lab or cost s are essen t ially const an t f or all t y pes of UTP f our - pair cable. indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  Lab or cost s for u pgr adin g in st alled cab le ( rem ov in g t he ex ist ing and inst alling new ) ar e and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t y pically gr eat er t h an t he cost of t h e or ig inal inst allat ion. net w or kin g p rof essionals, r egar dless of ex pert ise.

  UTP cable is back w ar d- comp at ible. Higher - cat eg ory cab le will sup por t low er - cat eg ory NI Cs, Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e bu t n ot v ice ver sa. har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  The p hy sical lif e of UTP cab le ( decades) is m uch lon ger t han t h e useable life of t h e t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . connect ed equ ipm en t . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

Auto-negotiation—An Optional Method for Automatically Configuring

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Link Operational Modes

  The p ur pose of aut on eg ot iat ion is t o f in d a w ay f or t w o NI Cs t hat sh are a UTP link t o com mu nicat e w it h each ot her , r eg ard less of w het her t h ey bot h imp lem ent ed t he sam e Et h er net

  Aut on eg ot iat ion is p er f orm ed t ot ally w it hin t he p hy sical lay er s d ur ing lin k init iat ion, w it h out an y add it ion al ov er h ead eit her t o t he MAC or t o high er pr ot ocol layer s. Aut onegot iat ion allow s UTP- based NI Cs t o d o t h e follow ing:

  Adv ert ise t h eir Et her net v ersion and any op t ional capab ilit ies t o t he NI C at t h e ot her end of t he lin k

  • Table of Content s

  Ackn ow ledg e r eceipt an d und er st andin g of t he oper at ional m odes t h at b ot h NI Cs shar e

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Reject an y oper at ional m odes t h at ar e n ot shar ed By Cisco Systems, Inc. Con figu re each NI C f or high est - level op er at ional m ode t h at bot h NI Cs can supp ort

  Pub lish er: Cisco Press

  Aut on eg ot iat ion is sp ecified as an opt ion for 1 0Base- T, 100 Base- TX, an d 1 00Base- T4, b ut it is

  Pub Dat e: Sep tem ber 1 1, 2 003

  r eq uir ed f or 10 0Base- T2 and 1 000Base- T im plem en t at ions. Table 8 - 4 list s t h e defined select ion

  I SBN: 1- 58 705 -1 19 -2 pr ior it y lev els ( high est lev el = t op pr ior it y) for UTP- b ased Et h er net NI Cs. Pages: 11 28

  

Tab le 8 -4 . The D ef i ne d A ut one got ia t i on Se le ct i on Lev e ls f or UTP N I Cs

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  [ 1 ] Se le ct ion Le v el Ope r at i ona l Mode Ma x im um Tot al D a t a Tra nsfe r Ra t e ( Mb ps) essent ial an d cu t t ing- edg e t ech nologies.

  9 10 00Base- T f ull- dup lex 20 00 Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom 8 10 00Base- T h alf - du plex 10 00 nov ice t o ex pert . 7 10 0Base- T2 f ull- dup lex 20 0

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP 6 10 0Base- TX fu ll- d uplex 20 0 Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 5 10 0Base- T2 h alf - du plex 10 0 Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . 4 10 0Base- T4 h alf - du plex 10 0

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  3 10 0Base- TX half- dup lex 10 0 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

  2

  10 Base- T full- du plex

  20 t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  1

  10 Base- T half- d uplex

  10 Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. [ 1]

  Because full- duplex oper ation allow s sim ult aneous tw o-w ay tr ansm ission, the m axim um total t ransfer r ate for full- duplex oper ation is double the half- duplex transmission r ate.

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on The au t onegot iat ion fu nct ion in UTP- based NI Cs uses a m odified 10Base- T link in t eg rit y pulse a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions seq uence in wh ich t h e NLPs ar e r eplaced by b ur st s of fast lin k pulses ( FLPs) , as show n in Figur e t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  8- 2 7 . Each FLP bur st is an alt er nat ing clock / dat a seq uence in wh ich t h e dat a bit s in t he b ur st

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy ident if y t he op er at ional m odes su ppor t ed by t h e t r ansm it t in g NI C and also p rov ide inf or mat ion syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich used by t he aut onegot iat ion han dshak e m echan ism . I f t h e NI C at t he ot h er en d of t he link is a pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease com pat ible NI C but does not hav e aut onegot iat ion cap abilit y, a par allel det ect ion f unct ion st ill pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient allow s it t o be r ecog nized. A NI C t h at f ails t o r esp ond t o FLP bur st s an d r et ur ns only NLPs is decisions for t h eir net w ork s. t r eat ed as a 10Base- T h alf- du plex NI C.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  At fir st glance, it may appear t h at t h e aut onegot iat ion p rocess wou ld alw ay s select t h e m ode supp ort ed by t he NI C wit h t h e lessor capabilit y , w hich wou ld b e t he case if bot h NI Cs u se t he sam e en cod ing pr ocedu r es an d lin k con figu rat ion . For exam ple, if bot h NI Cs ar e 1 00Base- TX b ut only on e suppor t s full- du plex oper at ion , t h e negot iat ed operat ion al m ode w ill be half- d uplex The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of 10 0Base- TX. Un for t un at ely , t h e diff erent 10 0Base ver sion s ar e not com p at ible w it h each ot her at essent ial an d cu t t ing- edg e t ech nologies. 10 0 Mbps, an d a 10 0Base- TX fu ll- d uplex NI C w ou ld au t onegot iat e w it h a 1 00Base- T4 NI C t o oper at e in 10Base- T h alf - du plex mod e.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Aut on eg ot iat ion in 10 00Base- X NI Cs is sim ilar t o au t onegot iat ion in UTP- based sy st ems, ex cept nov ice t o ex pert . t hat it cu rr ent ly app lies on ly t o com pat ible 1 000 Base- X devices and is cur rent ly con st r ained t o negot iat e only half - dup lex or f ull- du plex operat ion an d f low cont r ol d ir ect ion.

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Network Switches Provide a Second, and Often Better, Alternative to Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . Higher Link Speeds in CSMA/CD Network Upgrades

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Com pet it iv ely p riced n et wor k sw it ches became available on t he mar k et shor t ly af t er t he m id- enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing 19 90s an d essen t ially mad e net w or k repeat er s obsolet e for lar ge net w ork s. Alt hou gh repeat er s t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing can accept only one f r ame at a t ime and t hen send it t o all act iv e por t s ( ex cept t he por t on w hich indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . it is b ein g r eceiv ed ) , sw it ch es are eq uipped w it h t he f ollow ing : Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  MAC- based por t s w it h I / O fr am e buf fer s t h at eff ect iv ely isolat e t h e por t f r om t r aff ic being sen t at t he sam e t im e t o or fr om ot her por t s on t he sw it ch Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on

  Mu lt ip le in t ern al dat a pat h s t hat allow sev eral fr am es t o b e t r ansfer red bet w een dif fer en t a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions por t s at t he sam e t im e t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy These m ay seem lik e sm all d iff er ences, b ut t hey pr odu ce a m ajor ef fect in net w or k operat ion . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Becau se each por t p r ovides access t o a h igh- speed n et wor k b rid ge ( t h e sw it ch) , t he collision pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease dom ain in t he net w or k is r ed uced t o a series of sm all dom ains in w hich t he nu m ber of pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient par t icipant s is redu ced t o t wo—t he sw it ch p ort and t h e con nect ed NI C ( see Figur e 8- 2 8 ) . decisions for t h eir net w ork s. Fur t her mor e, because each p art icipan t is now in a pr iv at e collision d om ain , his or her av ailab le ban dw idt h has n ot on ly been m ar kedly in cr eased, it w as also d one w it hou t hav ing t o ch ange t he link speed.

  

Figu r e 8 - 2 8 . Repl acin g t he N et w or k R ep ea t e r s w i t h Sw i t ch e s Re duces

t h e Col li si on D om ai ns t o Tw o NI Cs Ea ch

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Con sider , f or exam ple, a 48- st at ion w or kg rou p wit h a cou ple of lar ge f ile ser ver s and sev eral Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e net w or k pr int er s on a 1 00- Mb ps CSMA/ CD net w or k. Th e av er age available b andw idt h , not har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on count in g in t er f ram e g aps an d collision r ecov er y , w ould be 1 00 ÷ 5 0 = 2 Mbps ( net w ork pr int a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions ser v ers d o n ot g en er at e n et w or k t r af fic) . On t he ot her han d, if t he sam e w or k gr oup w er e st ill on t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . a 1 0Base- T net w or k in wh ich t h e r ep eat er s had been replaced w it h net w or k sw it ch es, t h e Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy ban dw idt h av ailab le t o each u ser w ou ld b e 10 Mbp s. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Clear ly , n et w or k conf igur at ion is as im por t ant as r aw link speed. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. net w or k sw it ch es shou ld b e non sat u rat in g ( be capable of accept ing and t r ansfer r in g dat a at t he f ull r at e f rom each por t sim ult aneously ) .

Multispeed NICs

  • Table of Content s

  Aut o- n eg ot iat ion opened t h e door t o t h e developm ent of low - cost , m ult ispeed NI Cs t hat , f or

  • I ndex

  exam ple, sup por t b ot h half- and fu ll- d uplex oper at ion und er eit her 1 00Base- TX or 1 0Base- T

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  signaling pr oced ur es. Mult ispeed NI Cs allow st aged net w or k upg r ades in w h ich t he 10Base- T By Cisco Systems, Inc. half - dup lex end st at ions can be con nect ed t o 1 00Base- TX f ull- dup lex sw it ch por t s w it hout r eq uir ing t he NI C in t h e PC t o b e ch anged. Then, as mor e b andw idt h is n eeded for in divid ual PCs, t h e NI Cs in t hose PCs can be u pgr ad ed t o 100 Base- TX f ull- du plex mod e.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Choosing 1000Base-X Components and Media

  Alt hou gh Table 8 - 3 sh ows t hat t her e is con sid er able f lex ibilit y of choice in t he 10 00Base- X link m ed ia, t her e is not t ot al f lex ibilit y . Som e choices ar e p refer r ed ov er ot her s: The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  NI Cs at bot h ends of t he link m ust be t h e sam e 1 000 Base- X ver sion ( CX, LX, or SX) , and essent ial an d cu t t ing- edg e t ech nologies. t he lin k con nect ors mu st m at ch t he NI C con nect or s.

  The 1 000 Base- CX specif icat ion allow s eit h er st y le 1 or st y le 2 con nect or s, bu t st y le 2 is Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom pr efer red because some st y le 1 connect ors are not su it able for operat ion at 125 0 Mbps. nov ice t o ex pert .

  10 00Base- CX link s ar e int en ded f or pat ch - cor d use w it hin a com m unicat ions closet and ar e limit ed t o 25 met er s. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP The 1 000 Base- LX and 10 00Base- SX specificat ions allow eit her t he sm all f orm fact or SFF Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age MT- RJ or t h e lar ger dup lex SC conn ect or s. Because SFF MT- RJ conn ect or s ar e only ab out half as lar ge as dup lex SC connect or s, and becau se sp ace is a pr em iu m , it f ollow s t hat SFF Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . MT- RJ connect or s m ay become t he p redom inan t conn ect or .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat 10 00Base- LX t ran sceiver s gener ally cost mor e t h an 100 0Base- SX t r ansceiv er s.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The m ax im um op er at ing r ange for op t ical fiber s depend s on bot h t he t ran sm ission indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . w av elengt h an d t he m odal b andw idt h ( MHz.k m ) r at in g of t h e fib er . See Table 8 - 5 . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

Tab le 8 -5 . M a xi m um O pe r a t in g Ra nge s f or Com m on O pt i ca l Fi ber s

  har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Fibe r Cor e D ia m et e r / M oda l 1 0 0 0 Ba se - S X ( 8 5 0 n m 1 0 0 0 Ba se - LX ( 1 3 0 0 nm Ba ndw id t h W av e le ngt h ) W av e le ngt h ) [ 1]

  62 .5 m m ult im ode f iber 27 5 m et ers 55 0 m et ers

  m

  ( 20 0/ 50 0) MHz. km

  [ 1 ]

  50 m m m ult im ode f iber 50 0 m et ers 55 0 m et ers ( 40 0/ 40 0) MHz. km

  • Table of Content s

  [ 1 ]

  50 m m ult im ode f iber 55 0 m et ers 55 0 m et ers

  m

  • I ndex

  ( 50 0/ 50 0) MHz. km

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  10 m m single- m ode f iber Not su ppor t ed 50 00 m et er s

  Pub lish er: Cisco Press [ 1] Pub Dat e: Sep tem ber 1 1, 2 003 1000Base- LX tr ansceiv er s m ay also r equir e use of an offset -launch, m ode-condit ioning patch cor d wh en cou pling to some existing multim ode fiber s.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The op er at in g r ang es sh ow n in Table 8 - 5 ar e t hose sp ecified in t he I EEE 8 02. 3 st andar d. I n pr act ice, h ow ev er, t he m ax imu m oper at ing r ange f or LX t r ansceiv er s ov er 62 .5 m m ult im ode

  m

  fib er is appr ox imat ely 70 0 met er s, and som e LX t r ansceiv ers hav e been q ualified t o supp ort a 10 ,0 00- m et er oper at ing r ange ov er single- m ode f ib er . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Multiple-Rate Ethernet Networks

  Giv en t h e oppor t u nit ies sh ow n b y t he ex am ple in t he p rev iou s sect ions, it is not sur pr ising t h at Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom m ost lar ge Et hern et net w or ks are now im plem en t ed w it h a m ix of t r ansm ission rat es an d lin k nov ice t o ex pert . m ed ia, as show n in t he cable m odel in Figur e 8- 2 9 .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  

Figu r e 8 - 2 9 . A n Ex a m ple M u lt ir a t e Ne t w or k Topolog y—t h e I SO / I EC

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  

1 1 8 0 1 Cabl e M odel

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

  

[ View full size im age]

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . The I SO/ I EC 1 180 1 cable m od el is t he n et w or k m odel on w hich t he I EEE 8 02. 3 st andar d s ar e Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, based: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  Cam pu s dist r ibu t or

  — The t er m cam pus r efer s t o a f acilit y w it h t w o or m or e b uildings in a Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e r elat iv ely sm all ar ea. This is t he cen t r al point of t he cam pu s back bone an d t he t elecom har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on connect ion point wit h t h e out side w or ld. I n Et h er net LANs, t he cam pu s dist r ibut or wou ld a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t y pically be a g igabit sw it ch w it h t elecom int erf ace capabilit y . t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Bui ldi ng di st r ib ut or

  — This is t he building 's conn ect ion point t o t he cam pus backb one. An Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Et h er n et buildin g d ist r ibu t or w ould t y pically b e a 1 000 / 100 - or 1 000 / 100 / 10- Mbps sw it ch. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease

  Floor di st r ib ut or

  — This is t he floor 's conn ect ion point t o t he b uilding dist r ib ut or . I SO/ I EC pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient

  2

  11 801 r ecom m ends at least one f loor dist r ib ut or f or ev er y 10 00 m of f loor space in off ice decisions for t h eir net w ork s. env iron ment s, and, if p ossible, a separ at e d ist r ibut or for each floor in t he building . An Et h er n et floor d ist r ibu t or w ould t y pically b e a 1 000 / 100 / 10- or 10 0/ 10 - Mbp s sw it ch .

  Te le com out le t

  — This is t he net w ork con nect ion poin t f or PCs, w or kst at ion s, and pr int

  Cam pu s ba ck b one cab lin g

  — This is t y pically sing le- or m ult im ode cable t h at int er con nect s t he cent r al cam pus dist rib ut or w it h each of t h e building d ist r ibu t ors.

  Bui ldi ng ba ck bone cab li ng — This is t y pically Cat egor y 5 or bet t er UTP or m ult im ode fiber

  cable t hat int er connect s t he b uilding dist r ibut or w it h each of t he f loor dist rib ut or s in t he bu ild in g.

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  H ori zon t al ca bli ng

  — This is pr edom inant ly Cat egor y 5 or bet t er UTP cable, alt hou gh a f ew

  I ndex • inst allat ions ar e using m ult im ode f iber.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  As w it h UTP cable select ion, t h e ch oice of link media and int er mediat e n et wor k n odes should By Cisco Systems, Inc. alw ays be m ade w it h an ey e t o fu t ur e t r ansm ission rat e need s and t h e lif e exp ect an cy of t h e net w or k elem ent s, un pr ed ict ab le t hou gh t hey m ay be. I n t he 1 990 s, LAN t r an sm ission r at es

  Pub lish er: Cisco Press incr eased 100 t im es and, by 20 02, will in cr ease yet anot her 1 0 t im es.

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

  This d oes not m ean t hat all—or even som e—end st at ions and t h eir in t er conn ect ing link s w ill

  Pages: 11 28

  r eq uir e gigab it capabilit y . I t d oes mean, how ever , t hat m or e cent ral net w ork nodes ( such as m ost cam pus d ist r ibu t or s and m any b uilding dist r ib ut or s) shou ld b e eq uipped w it h gigabit capabilit y , and t h at all f loor dist r ib ut or s shou ld hav e at least 100 Mb ps capab ilit y . I t also means t hat all n et w or k sw it ch es sh ould be non blocking an d t h at all por t s should hav e f ull- dup lex capabilit y , and t h at any new camp us b ack bon e link s sh ould be inst alled w it h single- m ode f ib er . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Link Aggregation—Establishing Higher-Speed Network Trunks

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Lin k aggr egat ion is a r ecen t opt ion al MAC capabilit y t h at allow s sev eral phy sical lin ks t o be nov ice t o ex pert . com bined in t o on e logical high er - speed t r un k. I t pr ov ides t he means t o incr ease t h e eff ect iv e dat a r at e bet w een t w o net w ork nodes in unit m ult iples of t he ind ividu al link t r ansm ission r at e

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP r at her t h an in an or der- of - m agnit u de st ep. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  Lin k aggr egat ion can b e a cost - eff ect iv e w ay t o p r ovide higher - speed connect ions in Et h er net LANs t hat ar e r eaching sat ur at ion wit h 10 0 Mbps t r ansmission r at es bu t t h at w on 't requ ire Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . gigab it capab ilit y , at least in t h e shor t t er m . For exam ple, t h e m axim um leng t h for 6 2. 5 m m m ult im ode f iber lin ks is 200 0 m et ers at 1 00 Mbp s, and mu lt imod e fib er h as been of t en used f or

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  cam pus b ack bon e link s. The logical up gr ade w ould seem t o be t o r euse t hese lin ks for 1 000 enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing Mb ps oper at ion, b ut t he m ax imu m supp ort ab le len gt h for mu lt imod e fiber is on ly 700 m et er s t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing and only w it h 10 00Base- LX. I f t h e ex ist ing lin ks are lon ger t han 70 0 met er s, aggr egat ing n indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . exist ing link s w ill su ppor t an ef fect ive t ran sm ission r at e of ( 10 0 n ) Mbps. Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Lin k aggr egat ion should be v iewed as a net w ork con figur at ion opt ion t h at is pr im ar ily u sed in net w or kin g p rof essionals, r egar dless of ex pert ise. t he few int er connect ions t h at r equir e high er dat a rat es t h an can be pr ovid ed by sing le lin ks, such as sw it ch - t o- sw it ch and in sw it ch - t o- file serv er. I t can also be used t o incr ease t he r eliabilit y of Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e crit ical link s. Agg regat ed link s can b e r apidly r econ figu red ( t y pically in abou t 1 second or less) in har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on case of lin k failur e, w it h low r isk of d uplicat ed or r eor dered fr am es. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Lin k aggr egat ion does not aff ect eit her t he I EEE 802 .3 dat a f ram e f or mat ( s) or any higher lay er s Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy in t he p rot ocol st ack . I t is b ack w ar d- com pat ible w it h " agg regat ion - unaw ar e" d ev ices an d can be syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich used wit h any Et her net d at a r at e ( alt h ough it does not m ake sense for 10 Mbp s because it w ould pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease likely cost less t o pr ocur e a pair of 10 0- Mb ps NI Cs) . Lin k aggr egat ion can b e enabled only on pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient par allel point - t o- point lin ks and t hose t hat supp or t f ull- dup lex sam e- sp eed oper at ion. decisions for t h eir net w ork s.

  Network Management agent s t hat are com pat ib le w it h Sim ple Net w or k Manag em ent Prot ocol ( SNMP) an d t hat can be used t o gat her st at ist ics ab out t he oper at ion of t he net w or k nod es and t o assist in net w ork m anagem ent . Because user infor m at ion is anecdot al at best an d u su ally com es long aft er t he fact , all larg er net w ork s shou ld at least be conf igur ed w it h m anaged sw it ch es an d net w ork ser v ers t o ensur e t hat pot en t ial pr oblem s and bot t lenecks can be id en t ified b ef or e t hey cause ser ious net w ork d et er ior at ion.

  • Table of Content s
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By By now , it should be appar ent t hat upg rad in g ex ist in g net w ork s t y pically does not r eq uir e Cisco Systems, Inc.

  I ndex

Migrating to Higher-Speed Networks

  w holesale equ ipm en t or media ch anges, bu t it does r eq uir e kn ow ledg e of t he cu rr ent net w ork conf ig ur at ion and t he n et w or k locat ion of p ot ent ial pr ob lem s. This m eans t h at a net w or k

  Pub lish er: Cisco Press

  m anagem ent sy st em sh ould be in place and t hat a cab le plant dat abase shou ld b e bot h av ailab le

  Pub Dat e: Sep tem ber 1 1, 2 003

  and accur at e. I t is t im e- con su m in g an d oft en diff icu lt t o det erm ine link t yp e and av ailab ilit y af t er

  I SBN: 1- 58 705 -1 19 -2 t he cab les h ave been pu lled t hr oug h cond uit , b ur ied in w alls, an d lay ered in cab le t ray s. Pages: 11 28

  Lin ks ar e of t en t he limit in g f act ors in n et w or k u pgr ades. Ex ist in g Cat egor y 5 lin ks sh ould su ppor t all cur r en t Et her net r at es fr om 1 0 Mbps t o 10 00 Mbp s, alt houg h t hey sh ould be t est ed t o ensur e t heir capab ilit y t o supp ort gigab it r at es. I f t he net w or k is equip ped w it h only Cat eg ory 3 cable, som e lin ks will h ave t o b e replaced b ef or e up gr ading t o 1 000 Mb ps. A sim ilar sit u at ion ex ist s w it h sin gle- and m ult im ode f iber. Mult im ode f iber can not be u sed for all backb one inst allat ions. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of Single- m ode f iber, on t he ot h er h and, not only can sup por t all backb one lengt h s up t o 10, 00 0 essent ial an d cu t t ing- edg e t ech nologies. m et er s at 100 0 Mbps, b ut it also w ill be cap able of supp ort in g b ack bon e use at 10- g igabit dat a r at es in t he fu t ur e.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Sw it ch r eplacem ent can b eg in as soon as t h e necessary link s ar e av ailable. Ex ist in g sw it ches at nov ice t o ex pert . t he cam pu s and bu ild ing dist rib ut or levels can oft en be r eused at t he b uilding or f loor dist r ib ut or level. NI Cs can generally b e r ep laced t o ex t en d t he usefu l life of end st at ions. And so on . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary

  The ch apt er began w it h an ov er view of t h e Et her net t echn olog y, t he n et w or k b uilding blocks, and Et hern et ' s r elat ion sh ip t o t he I SO sev en- lay er ref er ence m odel. The r equir ement s for MAC and PHY com pat ib ilit y also w er e int r odu ced.

  • Table of Content s
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  I ndex

  The b asic MAC r esponsibilit ies wer e defin ed :

  D a t a en ca psul at i on

  — Assemb lin g t he f ram e in t o t h e defined for m at befor e t r ansm ission begins, an d disassemb lin g t he f ram e af t er it h as been r eceiv ed and checked for

  Pub lish er: Cisco Press t r ansm ission er r or s.

  Pub Dat e: Sep tem ber 1 1, 2 003 Me di a a cce ss cont r ol

  I SBN: 1- 58 705 -1 19 -2 — I n t h e r eq uired CSMA/ CD h alf- du plex m ode, and in t he op t ion al fu ll- dup lex m ode. Pages: 11 28

  Tw o op t ional MAC capab ilit y ex t ension s and t heir associat ed fr am e f orm at s w er e discu ssed. The

  VLAN t aggin g op t ion allow s n et w or k nod es t o b e defined w it h log ical as w ell as phy sical add resses, an d p rov ides a means t o assig n t ran smission p rior it ies on a fr am e- by - fr am e basis. A specif ic for m at f or t h e pause f r ame, w hich is used f or shor t - t er m link f low cont r ol, is defin ed in The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of t he st an dar d but w as not cover ed h er e because it is aut om at ic MAC capabilit y t hat is inv ok ed as essent ial an d cu t t ing- edg e t ech nologies. needed t o pr ev en t inp ut buf fer ov er r un . The PHY layer d iscussions included descr ipt ion s of t he signaling p rocedur es and m edia

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom r eq uir em ent s/ lim it at ion s for t he f ollow in g: nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  10 Base- T Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age 10 0Base- TX, 100 Base- T4, and 100 Base- T2 Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . 10 00Base- T, 10 00Base- CX, 1 000 Base- LX, and 100 0Base- SX

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Alt hou gh 100 Base- FX w as n ot specif ically d iscussed , it u ses t h e same sig naling pr ocedu r e as enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing 10 0Base- TX, but ov er op t ical fiber m edia r at h er t han UTP copper . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . The r em aining sect ions of t he chapt er w er e dev ot ed t o sy st ems con sid er at ions for b ot h t wist ed- Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, pair an d opt ical fiber LAN im plement at ion s: and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise.

  Lin k cr ossover r equir ement s in UTP n et wor k s Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e

  Mat chin g of PMD s and net w or k m ed ia t o en su re desir ed d at a r at es har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

  Use of link aggr egat ion t o cr eat e high er - speed logical t r u nk s t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

  I m plem ent at ion of m ult ispeed net w or k s syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Aft er essen t ially f inishing t he ch apt er, you shou ld hav e a r easonab le wor k ing k now led ge of t he pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Et h er n et pr ot ocol and net w or k t echnology . Th e nex t sect ion should help det er m ine w h et h er you decisions for t h eir net w ork s. need t o go back and r eread t he ch apt er.

Review Questions 1 :

  Shou ld n' t all 1 0Base- T net w or ks just be up gr aded t o 1 00 Mbp s? Why or w hy not ?

  • Table of Content s
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  2 : I ndex

  Which 100 Base ver sion ( s) ar e r ecom m en ded? W hy ?

  3 :

  Which 100 0Base v er sion( s) ar e r ecom m ended? Wher e w ould t hey be u sed? By Cisco Systems, Inc.

  4 :

  What cable t y pes should be used f or new net w or k s? For upg rad ing ex ist ing

  Pub lish er: Cisco Press

  net w or ks? Why ?

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 5 :

  How d o y ou kn ow w hen a net w or k needs t o be u pgr aded? Wher e do you st ar t ?

  Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 9. Fiber Distributed Data Interface Obj e ct i ve s Table of Content s • Pr ovid e backg r ound inf orm at ion abou t FDDI t echn ology . I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Ex plain how FDD I w or ks. By Cisco Systems, Inc. Descr ibe t he dif fer en ces b et w een FDD I and Copp er Dist rib ut ed D at a I nt er face ( CDDI ) . Pub lish er: Cisco Press Descr ibe h ow CD DI w or ks. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction

  The Fib er Dist ribu t ed Dat a I n t er f ace ( FDDI ) sp ecifies a 1 00- Mbps t oken- p assing , du al- r ing LAN using fib er - opt ic cab le. FDD I is fr equent ly used as h ig h- speed b ack bon e t ech nology b ecause of it s sup por t f or high b andw idt h and g reat er dist ances t han copp er . I t sh ould be not ed t hat

  • Table of Content s

  r elat iv ely recen t ly, a r elat ed copper specificat ion, called Cop per Dist r ib ut ed Dat a I n t er f ace

  • I ndex

  ( CD DI ) , has em erg ed t o pr ov id e 10 0- Mbp s ser v ice over copper . CD DI is t h e imp lem ent at ion of

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  FDDI p rot ocols ov er t w ist ed - pair copper w ir e. This chap t er focuses m ain ly on FDD I specif icat ions By and oper at ions, bu t it also pr ov id es a hig h- level ov erv iew of CDD I . Cisco Systems, Inc. FDDI u ses d ual- r in g archit ect ur e w it h t r aff ic on each rin g f low in g in opp osit e dir ect ions ( called

  Pub lish er: Cisco Press

  count er - r ot at ing) . The d ual r ing s con sist of a pr im ar y and a secon dar y r ing. Dur ing nor m al

  Pub Dat e: Sep tem ber 1 1, 2 003 oper at ion, t h e pr im ary ring is u sed for dat a t ran sm ission , and t he secondar y r ing r em ains id le.

  I SBN: 1- 58 705 -1 19 -2

  As w ill be discussed in det ail lat er in t his chap t er , t he pr im ar y pur pose of t h e du al r in gs is t o

  Pages: 11 28

  pr ov ide super ior r eliabilit y an d r obu st ness. Figur e 9- 1 sh ows t he coun t er - r ot at ing pr im ar y and second ar y FD DI r ings.

  

Figu r e 9 - 1 . FD DI Uses Coun t e r - Rot a t i ng Pr im a r y an d Seconda r y Ri ngs

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

Standards

  pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient FDDI w as d ev eloped b y t he Amer ican Nat ional St andar ds I n st it ut e ( ANSI ) X3 T9. 5 st an dar ds decisions for t h eir net w ork s. com mit t ee in t he m id- 1980 s. At t h e t im e, high- sp eed en gineerin g w or k st at ion s w ere b eg inning t o t ax t he b andw idt h of ex ist in g local- ar ea net w or ks ( LANs) based on Et her net and Tok en Ring.

  A n ew LAN media w as need ed t h at could easily sup por t t h ese w or k st at ion s and t heir new dist r ibut ed applicat ions. At t he sam e t im e, net w ork reliabilit y had becom e an in cr easin gly

  ANSI subm it t ed FD DI t o t he I nt er nat ion al Or gan izat ion f or St and ard izat ion ( I SO) , w hich cr eat ed an int er nat ional v er sion of FDDI t h at is com plet ely com pat ib le w it h t h e ANSI st andar d v er sion.

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Transmission Media

  FDDI u ses op t ical fiber as t he pr im ary t r ansmission m edium , b ut it also can ru n ov er copper cabling. As m en t ioned ear lier , FDDI over copp er is refer r ed t o as Cop per- Dist ribu t ed Dat a

  I n t erf ace ( CDDI )

  . Opt ical fiber h as sev eral adv ant ag es ov er copper m edia. I n par t icular, secur it y ,

  • Table of Content s

  r eliabilit y , and per for m ance all ar e enh anced w it h opt ical f ib er media becau se fiber d oes n ot

  I ndex •

  emit elect r ical sign als. A ph ysical m ed ium t h at d oes em it elect r ical signals ( copp er ) can b e

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  t app ed an d t h er efor e w ou ld per m it un aut h orized access t o t h e dat a t hat is t r ansit ing t he By m ed ium . I n addit ion, fiber is im m une t o elect r ical int erf erence f r om r adio f requ en cy in t erf erence Cisco Systems, Inc. ( RFI ) an d elect rom agn et ic in t erf er ence ( EMI ) . Fib er hist orically has sup por t ed m uch high er ban dw idt h ( t hr ou ghpu t p ot ent ial) t h an copp er , alt h ough r ecent t echnological ad van ces hav e

  Pub lish er: Cisco Press

  m ade copp er cap able of t r ansm it t ing at 1 00 Mbp s. Finally , FDDI allow s 2 k m bet w een st at ions

  Pub Dat e: Sep tem ber 1 1, 2 003 using m ult im ode f iber, and ev en lon ger dist ances using a sing le mod e.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  FDDI d ef ines t w o t yp es of op t ical fiber : sing le- m ode an d mu lt im od e. A m ode is a r ay of light t hat ent er s t he f iber at a par t icular ang le. Mu lt im od e f iber uses LED as t he light - generat in g device, w hile sin gle- m ode f iber gener ally uses laser s. Mu lt im ode fiber allow s m ult iple m odes of light t o pr opagat e t hr ough t h e fib er . Because t hese m odes of light ent er t he fiber at diff er ent angles, t hey w ill ar r ive at t he en d of t h e fib er at The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of dif fer en t t im es. This char act er ist ic is kn ow n as m odal dispersion . Mod al disper sion lim it s t he essent ial an d cu t t ing- edg e t ech nologies. ban dw idt h and dist ances t hat can be accom p lished using m ult imod e fib er s. For t his r eason, m ult im ode f iber is gener ally u sed for con nect iv it y w it hin a b uilding or a r elat iv ely g eog rap hically cont ained en vir onm ent .

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Single- m ode f iber allows only one m od e of lig ht t o p rop agat e t h rou gh t he f iber . Because on ly a single m ode of ligh t is u sed, m odal disper sion is n ot pr esen t w it h sin gle- mod e fib er . Th er efor e,

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP single- m ode f ib er is cap able of deliver ing con sid er ably h igher per for m ance conn ect iv it y over m uch lar g er d ist an ces, w hich is w hy it generally is u sed for con nect iv it y bet w een bu ild ings an d Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age w it hin en vir onm ent s t hat are m or e g eog rap hically d isp er sed .

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  

Figur e 9- 2 d ep ict s sin gle- m od e fiber u sin g a laser ligh t sour ce and m ult im ode f iber using a ligh t

I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat emit t in g diode ( LED) lig ht sou rce.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

Figu r e 9 - 2 . Lig ht Sou r ce s Di ff e r f or Sing le -M ode a n d M u lt im ode Fibe r s

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Specifications

  FDDI specifies t he p hy sical an d media- access p ort ion s of t he OSI r ef er ence m odel. FDDI is n ot act ually a sing le sp ecificat ion, but it is a collect ion of f our separ at e specif icat ion s, each w it h a specif ic fu nct ion. Com b in ed , t hese specif icat ion s hav e t he cap abilit y t o p rov ide h igh- speed

  Table of Content s •

  connect ivit y bet w een upp er - lay er pr ot ocols su ch as TCP/ I P and I PX, and m edia such as f ib er -

  I ndex • opt ic cab lin g.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  FDDI 's four sp ecificat ions ar e t he Media Access Cont r ol ( MAC) , Ph ysical Lay er Pr ot ocol ( PHY) , By Cisco Systems, Inc. Phy sical- Mediu m Dependent ( PMD ) , and St at ion Manag em ent ( SMT) sp ecificat ions. The MAC specif icat ion def in es how t h e m ed ium is accessed , includin g f r ame for m at , t ok en h andling ,

  Pub lish er: Cisco Press

  add ressin g, algor it hm s f or calcu lat ing cy clic redu ndan cy ch eck ( CRC) valu e, and er r or - recov er y

  Pub Dat e: Sep tem ber 1 1, 2 003

  m ech anism s. Th e PHY sp ecificat ion defines dat a encoding / decod in g pr ocedu res, clock ing

  I SBN: 1- 58 705 -1 19 -2

  r eq uir em ent s, an d f r amin g, am ong ot h er f un ct ion s. The PMD sp ecificat ion defines t h e

  Pages: 11 28

  char act er ist ics of t he t r ansm ission m ed iu m, inclu ding f ib er - op t ic lin ks, p ow er lev els, b it - er r or r at es, opt ical comp onent s, and conn ect or s. The SMT sp ecificat ion defines FDDI st at ion conf ig ur at ion, r ing conf ig ur at ion, an d r ing cont r ol f eat ur es, in clu ding st at ion in ser t ion an d r em ov al, init ializat ion, f ault isolat ion and r ecov er y , sch ed uling, and st at ist ics collect ion.

  FDDI is sim ilar t o I EEE 802. 3 Et hern et and I EEE 8 02. 5 Token Ring in it s r elat ion sh ip w it h t he The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of OSI m od el. I t s p r im ar y pu rp ose is t o p rov ide conn ect iv it y bet w een up per OSI lay ers of com m on essent ial an d cu t t ing- edg e t ech nologies. pr ot ocols and t h e media used t o connect n et w or k d ev ices. Figur e 9- 3 illust r at es t he four FDD I specif icat ion s and t heir r elat ion sh ip t o each ot h er and t o t h e I EEE- defined Logical Link Con t rol ( LLC) su blay er . Th e LLC sub lay er is a com pon en t of Layer 2 , t he MAC lay er, of t he OSI refer ence

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom m odel. nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  

Figu r e 9 - 3 . FD DI Specif icat ions M a p t o t he O SI Hie r a r chi ca l M od el

Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Station-Attachment Types

  On e of t he u nique ch aract er ist ics of FDDI is t hat mu lt ip le w ays act u ally ex ist by wh ich t o con nect FDDI d ev ices. FDDI defines f our t y pes of d ev ices: sing le- at t ach ment st at ion ( SAS) , dual-

  • Table of Content s

  at t achm ent st at ion ( D AS) , sin gle- at t ached concent r at or ( SAC) , and d ual- at t ached con cent r at or

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ndex ( DAC) .

  An SAS at t aches t o only on e rin g ( t he pr im ar y) t hr oug h a concen t r at or. One of t he pr im ary By Cisco Systems, Inc. adv ant ag es of con nect in g d ev ices wit h SAS at t achm en t s is t hat t he devices w ill not hav e any eff ect on t he FDDI r ing if t hey ar e disconnect ed or pow ered off . Con cent r at or s w ill be cov ered in

  Pub lish er: Cisco Press m or e det ail in t he f ollow ing d iscussion .

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

  Each FDDI DAS has t wo por t s, designat ed A an d B. These por t s connect t h e DAS t o t h e dual FDDI r ing . Ther ef or e, each por t p r ovides a con nect ion f or bot h t h e pr im ary an d t he secon dar y Pages: 11 28 r ings. As y ou w ill see in t he next sect ion, devices using DAS conn ect ions will af fect t h e r ings if t hey ar e d isconnect ed or pow ered off . Figur e 9- 4 sh ows FD DI DAS A and B por t s w it h at t achm ent s t o t he pr imar y an d secon dar y r ings.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  

Figu r e 9 - 4 . FD DI D AS Por t s A t t a ch t o t h e Pr im a r y an d Secon da r y Ri ngs

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on An FDDI concen t r at or ( also called a du al- at t ach m ent concen t r at or [ DAC] ) is t he b uilding block of a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . an FD DI n et w or k . I t at t ach es d irect ly t o b ot h t he p rim ar y and secon dar y r in gs an d ensur es t hat Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy t he failur e or p ower - dow n of any SAS does not br ing dow n t he ring . This is p ar t icu lar ly usefu l w hen PCs, or sim ilar d ev ices t hat are fr eq uent ly p ower ed on and of f, con nect t o t he r ing. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Figur e

  9- 5 pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease sh ows t he r ing at t achm ent s of an FDDI SAS, DAS, and concent r at or .

  pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  

Figu r e 9 - 5 . A Concen t r a t or A t t ach e s t o Bot h t h e Pr i m ar y a nd Secon da r y

Ri ng s

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Fault Tolerance

  FDDI p rov ides a num ber of f ault - t oler ant f eat ur es. I n par t icular , FDDI 's dual- r ing env ir on ment , t he im p lem ent at ion of t he op t ical by pass swit ch, and du al- h om in g su ppor t mak e FDDI a r esilien t m ed ia t echnology .

  Table of Content s •

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Dual Ring By Cisco Systems, Inc.

  FDDI 's pr imar y f ault - t oler ant f eat ur e is t he du al ring. I f a st at ion on t he d ual r ing f ails or is

  Pub lish er: Cisco Press

  pow er ed dow n , or if t he cab le is dam aged, t h e du al r ing is aut om at ically w r app ed ( d oubled back

  Pub Dat e: Sep tem ber 1 1, 2 003

  ont o it self ) int o a sing le rin g. Wh en t he rin g is w r app ed , t he dual- r ing t opology becom es a

  I SBN: 1- 58 705 -1 19 -2

  single- r in g t opology . Dat a cont inu es t o be t ran sm it t ed on t he FDDI rin g w it hou t p er f orm an ce

  Pages: 11 28

  im pact d ur ing t he w r ap con dit ion. Figur e 9- 6 an d Figur e 9- 7 illust r at e t h e ef fect of a r in g w r apping in FDDI .

  

Figu r e 9 - 6 . A Rin g Re cove r s f r om a St at ion Fai lu r e by W r app in g

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  

Figu r e 9 - 7 . A Rin g al so W r a ps t o W it hst a nd a Ca bl e Fa il ur e

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing When a sing le st at ion f ails, as sh own in Figur e 9- 6 , d ev ices on eit her side of t h e failed ( or indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . pow er ed - dow n) st at ion w r ap, for m ing a single r ing . Net wor k op er at ion cont inu es f or t h e Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, r em ainin g st at ions on t he r ing. When a cable f ailu re occur s, as show n in Figur e 9- 7 , d ev ices on and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all eit her sid e of t he cab le fault w rap . Net w ork operat ion cont inu es for all st at ion s. net w or kin g p rof essionals, r egar dless of ex pert ise. I t shou ld b e not ed t hat FD DI t r uly p rov ides f ault t oler ance again st a sing le failur e only . When Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e t w o or m ore f ailur es occur , t h e FDDI r ing seg m en t s int o t w o or m or e ind ep en dent ring s t hat ar e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on incapab le of com m unicat ing w it h each ot her . a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

Optical Bypass Switch

  pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient An opt ical by pass sw it ch p r ovides cont in uous d ual- r ing operat ion if a device on t he d ual r ing decisions for t h eir net w ork s. fails. This is used bot h t o pr event r ing segm ent at ion and t o elim inat e f ailed st at ions f r om t he r ing. The opt ical b yp ass sw it ch perf or ms t his f unct ion using opt ical m irr or s t h at p ass ligh t f r om t he rin g d ir ect ly t o t h e DAS device du rin g n orm al operat ion . I f a f ailu re of t he DAS device occur s, such as a p ower - off , t h e opt ical by pass sw it ch w ill p ass t he light t h rou gh it self by u sin g in t er nal

  The b en ef it of t h is capabilit y is t hat t h e rin g w ill n ot ent er a w rap ped con dit ion in case of a dev ice f ailur e. Figur e 9- 8 sh ows t he f unct ionalit y of an opt ical b yp ass sw it ch in an FDDI net w ork . When using t he OB, y ou w ill n ot ice a t r emend ous d ig ression of y our n et wor k as t he pack et s ar e sen t t h r ough t he OB u nit .

  

Figu r e 9 - 8 . The O pt i ca l Bypa ss Sw it ch Uses I nt er n al M i r r or s t o

  • Table of Content s

  

M a in t ai n a Ne t w or k

  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

Dual Homing

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Cr it ical dev ices, such as rou t er s or main fr am e host s, can u se a f ault - t oleran t t echniq ue called Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  

du al hom in g t o pr ov ide add it ional r edun dancy and t o help guar ant ee op er at ion. I n du al- hom ing

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all sit uat ions, t h e crit ical d ev ice is at t ached t o t w o con cent r at or s. Figur e 9- 9 sh ows a du al- hom ed net w or kin g p rof essionals, r egar dless of ex pert ise. conf ig ur at ion for d ev ices such as f ile ser ver s and r out er s.

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions

Figu r e 9 - 9 . A Du al -H om e d Con fi gur a t i on Gua r an t e es O pe r a t ion t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  On e pair of concent r at or link s is declared t he act iv e link ; t h e ot her pair is declar ed p assiv e. The passive link st ay s in back up m ode un t il t he pr imar y link ( or t he concent r at or t o w hich it is Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age at t ached) is det erm ined t o h ave failed . Wh en t his occur s, t he passiv e link au t omat ically act ivat es.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

FDDI Frame Format

  The FDD I fr am e f orm at is sim ilar t o t he f orm at of a Tok en Ring fr am e. This is one of t he ar eas in w hich FDD I bor r ow s heav ily f r om earlier LAN t ech nologies, su ch as Tok en Ring. FDD I fr am es can be as larg e as 4, 50 0 by t es. Figur e 9- 1 0 sh ows t he f ram e f or mat of an FD DI d at a f ram e an d

  • Table of Content s t ok en .
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 9 - 1 0 . Th e FD DI Fr am e I s Si m il ar t o Th at of a Tok en R in g Fr am e

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  

[ View full size im age]

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  FDDI Frame Fields Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  The f ollow in g d escr ipt ions sum m ar ize t he FDD I dat a fr am e and t ok en f ields illust r at ed in Figur e 9- 1 0 .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  P re am bl e — Gives a uniq ue seq uence t hat pr epar es each st at ion f or an up com ing f ram e.

  indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

  St a rt de li m it e r

  — I n dicat es t he begin ning of a f r ame by em ployin g a sig naling pat t er n t hat and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all dif fer en t iat es it fr om t he r est of t he f r ame. net w or kin g p rof essionals, r egar dless of ex pert ise.

  Fra m e cont rol

  — I n dicat es t he size of t he ad dr ess f ield s and w het her t h e fr am e cont ains Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e asyn ch r onous or sy nchr onou s dat a, amon g ot her cont r ol inf or mat ion . har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on

  D e st i na t ion a ddr ess

  a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions — Cont ains a un icast ( sin gular ) , m ult icast ( g rou p) , or br oadcast t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . ( ever y st at ion) addr ess. As w it h Et her net and Tok en Ring addr esses, FDDI d est inat ion Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy add resses ar e 6 by t es long . syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

  Sou rce ad dre ss

  — I d en t ifies t he sing le st at ion t h at sent t he f ram e. As w it h Et h er n et and pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease Tok en Rin g ad dr esses, FD DI sour ce addr esses ar e 6 by t es long. pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  D a t a

  — Cont ains eit h er in for m at ion dest in ed for an upper - lay er p r ot ocol or cont r ol inf orm at ion.

  Fra m e ch eck se que nce ( FCS)

  — I s filed b y t he sour ce st at ion wit h a calculat ed cy clic dam aged in t ran sit . I f so, t he f ram e is d iscar ded.

  End de li m it e r

  — Cont ains uniqu e sym bols; can not be dat a sym bols t hat in dicat e t he end of t he fr am e.

  Fra m e st a t us

  — Allow s t h e sour ce st at ion t o det erm ine w h et h er an er r or occu rr ed; ident if ies w h et h er t he f ram e w as r ecognized and cop ied by a r eceivin g st at ion.

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Copper Distributed Data Interface

  Cop per Dist r ib ut ed Dat a I n t er f ace ( CDDI ) is t he im plem en t at ion of FDD I pr ot ocols over t w ist ed- pair copp er w ir e. Lik e FDDI , CDDI p rov ides dat a r at es of 100 Mb ps an d u ses d ual- r in g ar ch it ect u re t o pr ov ide r edun dancy . CDD I supp ort s dist ances of about 100 m et ers f r om deskt op

  • Table of Content s t o con cent r at or .
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  CD DI is def in ed by t he ANSI X3 T9. 5 Com mit t ee. The CDDI st an dar d is off icially nam ed t he Tw ist ed - Pair Phy sical Med iu m- Dep en dent ( TP- PMD) st andar d. I t is also r efer red t o as t he By Cisco Systems, Inc. Tw ist ed - Pair Dist rib ut ed D at a I nt er face ( TP- D DI ) , consist en t w it h t he t er m Fiber Dist r ib ut ed Dat a I nt erf ace ( FDDI ) . CD DI is consist en t w it h t he phy sical an d media- access cont r ol lay er s

  Pub lish er: Cisco Press defin ed by t he ANSI st and ar d.

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

  The ANSI st an dar d recognizes only t wo t y pes of cables for CDDI : sh ielded t w ist ed pair ( STP) and

  Pages: 11 28

  un sh ielded t w ist ed pair ( UTP) . STP cabling has 1 50- oh m im pedance and adh er es t o EI A/ TI A 56 8 ( I BM Ty pe 1) sp ecificat ions. UTP is d at a- gr ade cabling ( Cat eg ory 5) consist ing of fou r unsh ielded pair s using t igh t - pair t w ist s an d specially d ev eloped in su lat in g polym er s in p last ic jacket s adh er ing t o EI A/ TI A 56 8B specificat ions.

  Figur e 9- 1 1 illust r at es t he CDDI TP- PMD sp ecificat ion in r elat ion t o t he r em aining FDDI

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of specif icat ion s. essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  

Figu r e 9 - 1 1 . CDD I TP- PM D an d FD DI Specif ica t i ons A dhe r e t o Di ff e r en t

nov ice t o ex pert .

  

St an da r ds

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary

  The Fiber Dist r ibut ed Dat a I nt erf ace ( FDDI ) specifies a 1 00- Mbps t oken- p assing , dual- r ing LAN ar ch it ect u re usin g fiber - opt ic cable. FDDI is f r eq uent ly im plement ed as a high- sp eed backb one t echnology b ecau se of it s su ppor t for h ig h band wid t h an d gr eat er d ist an ces t h an cop per.

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1 :

  What ar e t he benefit s of using FDDI in st ead of CD DI ?

  Table of Content s • 2 : I ndex

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  What r ole does t he DAC play in t he FDDI net w ork ?

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Part III: WAN Technologies Ch apt er 10 Fr am e Relay Ch apt er 11 Hig h- Speed Ser ial I nt er face

  • Table of Content s

  Ch apt er 12 I ndex I n t eg rat ed Serv ices Digit al Net w or k • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Ch apt er 13 Poin t - t o- Point Pr ot ocol By Cisco Systems, Inc. Ch apt er 14 Sw it ched Mult im egabit Dat a Ser v ice

  Pub lish er: Cisco Press Ch apt er 15 D ialu p Techn olog y Pub Dat e: Sep tem ber 1 1, 2 003 Ch apt er 16 Sy nchr on ous Dat a Link Cont r ol an d Der iv at ives

  I SBN: 1- 58 705 -1 19 -2 Ch apt er 17 X. 2 5

  Pages: 11 28 Ch apt er 18 Vir t ual Pr iv at e Net w or ks ( VPNs)

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 10. Frame Relay Obj e ct i ve s Table of Content s • Descr ibe t he hist or y of Fram e Relay . I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Descr ibe h ow Fr ame Relay w or k s. By Cisco Systems, Inc. Descr ibe t he pr im ar y fun ct ion alit y t r ait s of Fr am e Relay . Pub lish er: Cisco Press Descr ibe Fr am e Relay net w or k imp lem ent at ion. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Descr ibe t he f orm at of Fr am e Relay fr am es. Pages: 11 28 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction

  Fram e Relay

  is a high - per for m ance WAN p rot ocol t hat operat es at t he phy sical and dat a lin k lay er s of t h e OSI r efer en ce m od el. Fr am e Relay orig in ally was desig ned f or use acr oss I nt egr at ed Ser v ices Digit al Net w or k ( I SDN) int er faces. Tod ay, it is used over a var iet y of ot her

  • Table of Content s

  net w or k int er faces as w ell. Th is chapt er f ocu ses on Fr ame Relay ' s sp ecificat ions and applicat ions

  I ndex • in t he cont ex t of WAN ser v ices.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Fram e Relay is an ex amp le of a pack et - sw it ched t ech nology . Packet - sw it ched n et wor k s enable By Cisco Systems, Inc. end st at ions t o dy nam ically shar e t h e net w or k m ed iu m and t h e available b andw idt h . The follow ing t w o t echn iq ues ar e used in pack et - sw it ching t echnolog y:

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

  Var iable- leng t h packet s

  Pages: 11 28

  St at ist ical m ult iplexing Var iable- leng t h packet s ar e u sed for m or e eff icient and flex ib le dat a t r ansfer s. These p ack et s ar e sw it ch ed bet w een t h e v arious segm ent s in t h e net w ork unt il t he dest inat ion is r eached.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of St at ist ical m ult iplexing t echniqu es con t r ol net w or k access in a pack et - sw it ched net w ork . Th e essent ial an d cu t t ing- edg e t ech nologies. adv ant ag e of t his t echn iq ue is t h at it accom m odat es m or e flexib ilit y an d mor e eff icient use of ban dw idt h. Most of t od ay' s pop ular LANs, such as Et hern et and Tok en Rin g, ar e pack et - sw it ched net w or ks.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . Fram e Relay of t en is d escr ibed as a st r eam lined ver sion of X. 25, off er ing f ew er of t he rob ust capabilit ies, su ch as w ind ow in g an d ret r ansm ission of last dat a t hat ar e off er ed in X. 25 . This is

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP because Fram e Relay t y pically oper at es over WAN facilit ies t h at of fer m or e r eliable conn ect ion ser v ices an d a high er degr ee of r eliabilit y t han t he facilit ies av ailab le dur ing t h e lat e 19 70s an d

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age early 1 980 s t hat ser v ed as t he com mon p lat f or m s for X. 2 5 WANs. As m ent ion ed earlier , Fram e Relay is st r ict ly a Lay er 2 pr ot ocol su it e, w hereas X. 25 pr ov ides ser v ices at Lay er 3 ( t he n et w or k Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . lay er ) as w ell. Th is en ables Fr am e Relay t o off er h igher p er for m ance an d g reat er t r ansm ission eff iciency t han X. 25 , and m akes Fr am e Relay su it able for cu r rent WAN ap plicat ion s, su ch as LAN

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat int er con nect ion .

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y,

Frame Relay Standardization

  and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. I nit ial p rop osals f or t h e st andar dizat ion of Fram e Relay w er e pr esent ed t o t h e Con su lt at ive Com m it t ee on I n t er n at ional Telep hone an d Telegr aph ( CCI TT) in 198 4. Because of lack of Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e int er operab ilit y and lack of com plet e st and ard izat ion , how ev er , Fr am e Relay did not ex per ien ce har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on signif icant deploy m en t d ur in g t he lat e 1 980 s. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . A m aj or dev elopm ent in Fr am e Relay' s hist or y occu r red in 1 990 w hen Cisco, Digit al Equip ment Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Cor por at ion ( DEC) , Nor t her n Telecom , and St rat aCom f orm ed a consor t ium t o focus on Fr am e syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Relay t ech nology d ev elopm en t . This con sor t ium developed a specif icat ion t h at conf orm ed t o t h e pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease basic Fr ame Relay p r ot ocol t hat w as being discu ssed in CCI TT, but it ex t ended t he p rot ocol w it h pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient feat u res t h at p rov ide ad dit ional capab ilit ies f or comp lex in t er net w or k in g en vir onm ent s. These decisions for t h eir net w ork s. Fram e Relay ex t ension s ar e r ef er r ed t o collect ively as t h e Local Managem en t I nt er face ( LMI ) .

  Since t he con sor t ium ' s specif icat ion w as dev elop ed and p ublished, m any v endor s h ave ann ounced t heir su ppor t of t his ex t en ded Fr am e Relay definit ion . ANSI and CCI TT hav e

  I nt er nat ionally , Fram e Relay w as st and ar dized b y t he I nt er nat ion al Telecom mu nicat ion Union—Telecom m unicat ions St an dar ds Sect ion ( I TU- T) . I n t he Unit ed St at es, Fr am e Relay is an Am er ican Nat ion al St and ar ds I nst it ut e ( ANSI ) st andar d.

  • Table of Content s

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Frame Relay Devices

  Dev ices at t ached t o a Fram e Relay WAN fall in t o t h e follow ing t w o g en er al cat egor ies:

  • I ndex •

  Table of Content s

  Dat a t erm inal eq uipm ent ( DTE)

  Dat a cir cuit - t er m in at ing equipm ent ( DCE)

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  DTEs gener ally ar e consider ed t o be t er m in at ing eq uipm ent for a specif ic net w ork and t y pically ar e locat ed on t he p r em ises of a cust om er . I n fact , t hey m ay be ow ned by t h e cust om er .

  Pub lish er: Cisco Press Ex am ples of DTE dev ices ar e t erm inals, p er sonal com pu t er s, r out er s, and br idges.

  Pub Dat e: Sep tem ber 1 1, 2 003

  DCEs ar e carr ier- own ed int er net w or kin g d ev ices. Th e pur pose of D CE eq uipm ent is t o pr ov ide

  I SBN: 1- 58 705 -1 19 -2

  clock ing and sw it ch in g ser vices in a net w or k, w hich ar e t h e devices t hat act ually t r ansm it dat a

  Pages: 11 28

  t hr ou gh t he WAN. I n m ost cases, t h ese ar e p ack et sw it ches. Figur e 10 - 1 sh ows t he r elat ion sh ip bet w een t h e t w o cat egor ies of devices.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  

Figu r e 1 0 - 1 . D CEs Ge ne r al ly Resid e W i t h in Car r i er - O per a t e d W A Ns

essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . The con nect ion bet w een a DTE device and a DCE dev ice consist s of bot h a phy sical lay er Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy com ponent and a link lay er comp onent . The ph ysical comp onent defines t h e m echan ical, syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich elect r ical, f un ct ion al, and pr oced ur al specif icat ion s for t he conn ect ion bet w een t he d ev ices. One pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease of t he most com m only u sed phy sical layer int er face specificat ions is t h e recom mend ed st and ar d pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient ( RS) - 2 32 specif icat ion . The link lay er comp onent defines t h e pr ot ocol t hat est ablish es t he decisions for t h eir net w ork s. connect ion bet w een t he D TE d ev ice, su ch as a r out er, and t he D CE device, such as a sw it ch . This chapt er ex am in es a com mon ly ut ilized p rot ocol specificat ion used in WAN net w or k in g: t he Fr ame Relay pr ot ocol.

Frame Relay Virtual Circuits

  Fram e Relay p rov ides conn ect ion- or ient ed d at a link lay er com mu nicat ion . This m eans t hat a defin ed com mu nicat ion ex ist s bet w een each pair of d ev ices an d t hat t hese con nect ion s ar e associat ed wit h a con nect ion ident if ier . Th is ser v ice is im plem en t ed b y using a Fr ame Relay

  • Table of Content s

  v irt u al circuit , w hich is a logical con nect ion cr eat ed bet w een t w o dat a t er m inal equ ipm en t ( D TE)

  I ndex • dev ices acr oss a Fram e Relay p ack et - sw it ch ed net w or k ( PSN) .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Vir t ual cir cu it s pr ov id e a b idirect ional com m unicat ion pat h fr om one DTE dev ice t o anot h er and By Cisco Systems, Inc. ar e un iq uely ident ified by a dat a- link conn ect ion ident ifier ( DLCI ) . A num ber of v ir t ual cir cu it s can be m ult iplexed int o a single p hy sical cir cu it f or t r ansm ission acr oss t he n et wor k . This

  Pub lish er: Cisco Press

  capabilit y of t en can r ed uce t he equ ip m en t an d n et w or k com plexit y r equir ed t o conn ect mu lt ip le

  Pub Dat e: Sep tem ber 1 1, 2 003 DTE dev ices.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  A v ir t ual cir cuit can pass t hr ou gh any nu m ber of int er mediat e D CE devices ( sw it ch es) locat ed w it hin t he Fr am e Relay PSN. Fram e Relay v ir t ual cir cu it s fall in t o t w o cat eg ories: sw it ch ed v ir t ual cir cu it s ( SVCs) an d per m anent v ir t ual cir cuit s ( PVCs) . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

Switched Virtual Circuits

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  Sw it ch ed v ir t ual circuit s ( SVCs) ar e t em por ar y connect ions u sed in sit uat ion s r eq uir in g only nov ice t o ex pert .

  spor adic dat a t r ansfer b et ween DTE devices acr oss t h e Fr am e Relay net w or k . A com m unicat ion session acr oss an SVC consist s of t he follow in g four operat ion al st at es: New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

Cal l se t up — The v irt u al circuit bet w een t w o Fr am e Relay DTE dev ices is est ablish ed .

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  D a t a t ra nsfe r — Dat a is t ran sm it t ed bet w een t he DTE devices over t h e v ir t u al cir cuit .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat I dl e — The connect ion bet w een DTE devices is st ill act iv e, bu t n o dat a is t r ansf er r ed . I f an

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing SVC rem ains in an idle st at e for a d ef ined p er iod of t ime, t he call can b e t erm inat ed . t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Cal l t er m ina t i on — The v irt u al circuit bet w een DTE dev ices is t er m in at ed.

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Aft er t he v irt u al circuit is t er minat ed , t he D TE devices mu st est ablish a new SVC if t here is net w or kin g p rof essionals, r egar dless of ex pert ise. add it ion al dat a t o be exchan ged. I t is ex pect ed t hat SVCs w ill be est ablished, m aint ained, and t er min at ed using t h e sam e sign alin g p rot ocols u sed in I SDN.

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on Few m anuf act u r er s of Fr ame Relay DCE equipm ent su ppor t sw it ched v ir t u al cir cuit con nect ion s. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions Ther ef or e, t heir act ual d ep loy m ent is min im al in t od ay' s Fram e Relay n et w or k s. t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy Pr ev iously not w idely su ppor t ed by Fr ame Relay eq uipm en t , SVCs are now t h e nor m . Com pan ies hav e f ound t h at SVCs sav e m oney in t he end because t he cir cuit is n ot op en all t h e t im e. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Permanent Virtual Circuits

  Perm an en t v ir t u al cir cu it s ( PVCs)

  ar e p er m anent ly est ablished conn ect ions t hat are used f or used wit h SVCs. PVCs alw ays op er at e in one of t he f ollow ing t w o operat ion al st at es:

  D a t a t ra nsfe r — Dat a is t ran sm it t ed bet w een t he DTE devices over t h e v ir t u al cir cuit . I dl e

  — The connect ion bet w een DTE devices is act ive, b ut no d at a is t r ansf er r ed. Unlike SVCs, PVCs w ill not b e t erm inat ed un der any cir cu m st an ces w h en in an id le st at e.

  • Table of Content s

  DTE dev ices can begin t r ansferr ing d at a w henev er t hey ar e r ead y becau se t he cir cu it is

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  I ndex per m anent ly est ablish ed .

Data-Link Connection Identifier

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  Fram e Relay v ir t ual cir cu it s ar e ident ified by dat a- link connect ion ident ifier s ( DLCI s) . D LCI v alues t y pically are assigned by t h e Fram e Relay serv ice pr ov id er ( for ex am ple, t he t elephon e

  I SBN: 1- 58 705 -1 19 -2 com pany ) . Pages: 11 28

  Fram e Relay D LCI s h ave local signif ican ce, w h ich m ean s t hat t heir v alues ar e uniq ue in t he LAN, bu t n ot necessar ily in t h e Fram e Relay WAN.

  Figur e 10 - 2 illust r at es how t w o dif fer en t DTE d ev ices can be assigned t he sam e DLCI v alue

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of w it hin one Fr am e Relay WAN. essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  

Figu r e 1 0 - 2 . A Sin gle Fr am e R el ay Vi r t u al Cir cu it Can Be A ssi gne d

nov ice t o ex pert .

  

Di f fe r en t DLCI s on Ea ch En d of a VC

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Congestion-Control Mechanisms

  Fram e Relay r educes net w or k ov er head by im plem en t ing sim ple cong est ion- not ificat ion m ech anism s r at h er t han ex plicit , per - v ir t u al- cir cuit f low cont r ol. Fr ame Relay t yp ically is im plem ent ed on reliable net w or k m edia, so dat a int egr it y is n ot sacrif iced becau se flow cont rol

  • Table of Content s

  can be left t o h ig her- lay er pr ot ocols. Fr am e Relay im plement s t w o cong est ion- n ot ificat ion

  I ndex •

  m ech anism s:

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Forw ar d- ex plicit congest ion not ificat ion ( FECN)

  Pub lish er: Cisco Press

  Backw ar d- ex plicit congest ion n ot ificat ion ( BECN)

  Pub Dat e: Sep tem ber 1 1, 2 003 FECN and BECN each is cont r olled by a single b it cont ained in t he Fram e Relay f r ame header.

  I SBN: 1- 58 705 -1 19 -2

  The Fr am e Relay fr am e header also cont ain s a D iscar d Elig ibilit y ( DE) bit , w h ich is used t o

  Pages: 11 28 ident if y less im por t ant t r aff ic t hat can b e dr opp ed du rin g p er iods of con gest ion .

  The FECN bit is par t of t h e Addr ess field in t he Fr am e Relay fr am e header . Th e FECN m echanism is init iat ed wh en a DTE device sends Fr am e Relay fr am es int o t he net w or k . I f t he net w or k is congest ed, DCE d ev ices ( sw it ches) set t h e v alu e of t he f r ames' FECN bit t o 1. W hen t he fr am es The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of r each t he dest in at ion D TE d ev ice, t he Add r ess f ield ( w it h t he FECN bit set ) in dicat es t hat t he essent ial an d cu t t ing- edg e t ech nologies. fr am e ex perienced cong est ion in t he pat h f r om sour ce t o dest inat ion. The DTE d ev ice can r elay t his in for m at ion t o a higher - layer p rot ocol for p rocessing . Dependin g on t h e imp lem ent at ion , flow con t r ol m ay be in it iat ed, or t he in dicat ion m ay b e ignor ed.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . The BECN bit is par t of t h e Addr ess field in t he Fr am e Relay fr am e header . DCE devices set t he v alue of t he BECN bit t o 1 in f r ames t r av eling in t he opposit e dir ect ion of f ram es w it h t heir FECN

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP bit set . This inf orm s t h e r eceiving DTE d ev ice t hat a p art icular p at h t hr ough t h e net w or k is congest ed. The DTE device t h en can relay t his in for m at ion t o a h igher - layer p rot ocol f or

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age pr ocessing. Depending on t he im p lem ent at ion, flow - cont r ol m ay be in it iat ed , or t h e indicat ion m ay be ig nor ed .

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing

Frame Relay Discard Eligibility

  t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . The Discar d Eligib ilit y ( DE) b it is used t o in dicat e t hat a f r am e has low er imp or t ance t han ot h er Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, fr am es. The DE b it is par t of t he Ad dr ess f ield in t he Fr ame Relay f r am e header. and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. DTE dev ices can set t he v alue of t h e DE bit of a f ram e t o 1 t o ind icat e t hat t he f ram e h as low er im por t ance t han ot h er fr am es. Wh en t h e net w or k becomes cong est ed, D CE devices w ill discar d Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e fr am es w it h t he DE b it set befor e d iscar ding t hose t h at d o not . This r educes t he lik elih ood of har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on crit ical d at a b eing d rop ped b y Fram e Relay DCE devices dur ing per iods of congest ion. a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich

Frame Relay Error Checking

  pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient Fram e Relay u ses a com m on err or - check ing m ech anism kn ow n as t he cyclic r edun dancy check decisions for t h eir net w ork s.

  ( CRC)

  . Th e CRC com par es t w o calcu lat ed v alues t o d et er m ine w het her er r ors occur r ed d ur in g t he t ran smission f rom sou r ce t o dest inat ion. Fr am e Relay r ed uces net w ork over head b y im plem ent in g er r or check ing r at her t han er ror cor r ect ion . Fram e Relay t y pically is imp lem ent ed on r eliable n et w or k m edia, so d at a int egr it y is n ot sacr if iced because er r or cor rect ion can be lef t

Frame Relay Local Management Interface

  The Local Man agem ent I nt er face ( LM I ) is a set of enhan cem en t s t o t he b asic Fr am e Relay specif icat ion . The LMI w as d ev elop ed in 19 90 by Cisco Sy st em s, St r at aCom , Nor t h er n Telecom , and Dig it al Equ ipm en t Corp orat ion . I t of fer s a n um ber of f eat u res ( called ex t en sion s) for

  • Table of Content s

  m anagin g com plex int er net w ork s. Key Fram e Relay LMI ext en sions in clu de glob al add ressin g,

  • I ndex v irt u al circuit st at us m essag es, an d m ult icast ing.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  The LMI g lob al add ressin g ex t ension g ives Fr ame Relay d at a- link conn ect ion ident ifier ( DLCI ) By Cisco Systems, Inc. v alues global rat h er t han local sig nificance. DLCI v alu es becom e D TE ad dr esses t hat ar e uniq ue in t he Fr ame Relay WAN. The g lobal add r essing ex t ension ad ds f unct ionalit y an d man ageabilit y

  Pub lish er: Cisco Press

  t o Fr am e Relay int er net w ork s. I nd iv idu al net w or k int erf aces and t he end nod es at t ached t o

  Pub Dat e: Sep tem ber 1 1, 2 003

  t hem , f or exam ple, can be ident if ied by usin g st an dar d addr ess- r esolu t ion an d d iscov er y

  I SBN: 1- 58 705 -1 19 -2

  t echniqu es. I n add it ion , t he en t ir e Fr am e Relay net w or k appear s t o be a t yp ical LAN t o r out ers

  Pages: 11 28 on it s per ipher y.

  LMI vir t u al cir cuit st at us m essages p rov ide com m unicat ion and sy nchr on izat ion b et w een Fr am e Relay DTE and DCE d ev ices. Th ese m essages ar e u sed t o p er iodically repor t on t he st at u s of PVCs, w hich pr event s dat a f r om being sen t int o black holes ( t h at is, ov er PVCs t h at no longer exist ) .

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. The LMI m ult icast ing ex t ension allow s m ult icast g rou ps t o be assigned. Mult icast in g sav es ban dw idt h by allow ing r out ing up dat es and add r ess- r esolut ion m essages t o be sen t on ly t o specif ic gr oup s of rou t ers. Th e ex t ension also t r ansmit s repor t s on t h e st at us of m ult icast g rou ps

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom in upd at e m essages. nov ice t o ex pert .

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Frame Relay Network Implementation

  A com m on pr iv at e Fr am e Relay net w or k imp lem ent at ion is t o eq uip a T1 m ult iplexer w it h bot h Fram e Relay an d n on- Fr ame Relay in t erf aces. Fr ame Relay t raf fic is f or w ard ed out t he Fr am e Relay int er face and ont o t h e dat a net w ork . Non - Fr am e Relay t r aff ic is for w ar ded t o t h e

  Table of Content s •

  app rop riat e applicat ion or ser vice, such as a p riv at e br an ch exchan ge ( PBX) for t elephon e

  I ndex • ser v ice or t o a v id eo- t eleconfer en cin g ap plicat ion .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  A t yp ical Fr am e Relay net w or k con sist s of a num b er of D TE d ev ices, such as r out er s, connect ed By Cisco Systems, Inc. t o rem ot e por t s on m ult ip lex er eq uipm ent via t rad it ional p oin t - t o- poin t serv ices such as T1 , fr act ional T1, or 5 6- Kb cir cuit s. An exam ple of a sim p le Fr am e Relay net w or k is show n in Figur e

  Pub lish er: Cisco Press 10 - 3 .

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 1 0 - 3 . A Sim pl e Fr a m e Re la y Ne t w or k Con ne ct s Var i ous D ev ices

t o Di ff e r en t Se r vi ces ov er a W AN

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The m aj or it y of Fr am e Relay net w or ks deployed t oday are p r ovisioned b y ser v ice p r ovider s t hat int end t o off er t ran sm ission serv ices t o cust om er s. Th is is oft en ref er r ed t o as a pub lic Fr am e Relay ser v ice. Fr am e Relay is imp lem ent ed in b ot h p ublic car r ier - pr ov ided n et w or k s and in pr iv at e ent erp r ise n et w or k s. The f ollow ing sect ion exam ines t h e t w o m et hod olog ies f or deploy ing

Public Carrier-Provided Networks

  I n pub lic car r ier - pr ov ided Fr am e Relay net w or ks, t h e Fr am e Relay sw it ch ing eq uipm ent is locat ed in t he cent r al of fices of a t elecom m unicat ions car r ier . Su bscr iber s ar e char ged b ased on t heir n et w or k use b ut are r eliev ed f r om adm inist erin g an d m aint ain ing t he Fr ame Relay net w ork equipm ent and ser v ice.

  • Table of Content s
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I ndex

  Gener ally , t h e DCE equ ip m en t also is ow ned by t h e t elecom m unicat ions p rov ider . DCE

  equipm ent eit her w ill be cust om er - ow n ed or p er hap s w ill be ow ned by t h e t elecom m unicat ions pr ov ider as a ser vice t o t he cust om er.

  By Cisco Systems, Inc.

  The m aj or it y of t oday 's Fr am e Relay net w or ks ar e p ublic car rier - pr ov id ed n et w or k s.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2

Private Enterprise Networks

  Pages: 11 28

  Mor e f requ en t ly, org anizat ions w or ldw ide ar e d ep loy ing pr iv at e Fram e Relay n et w or k s. I n pr iv at e Fram e Relay n et w or k s, t he ad min ist r at ion and m aint enance of t h e net w ork are t he r espon sib ilit ies of t he en t er pr ise ( a pr iv at e com pan y) . All t he equ ip m en t , includin g t h e sw it ch in g equipm ent , is ow ned b y t he cu st om er . The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Frame Relay Frame Formats

  To u nder st and m uch of t he f unct ionalit y of Fr ame Relay , it is helpfu l t o und er st and t he st r uct u re of t he Fr am e Relay fr am e. Figur e 10 - 4 d ep ict s t he b asic f or mat of t he Fr am e Relay fr am e, and

  Figur e 10 - 5 illust r at es t he LMI v ersion of t he Fr am e Relay fr am e.

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Figu r e 1 0 - 4 . Fiv e Fi el ds Com p r ise t he Fr a m e Re la y Fr a m e

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  

Figu r e 1 0 - 5 . N in e Fi el ds Com pr i se t he Fr am e Rel ay Th at Conf or m s t o Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

nov ice t o ex pert .

t h e LM I For m at

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  

[ View full size im age]

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Flags ind icat e t h e beginn ing and end of t he f ram e. Th ree pr im ar y com p onent s m ak e up t he and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Fram e Relay f r ame: t he h ead er an d addr ess area, t h e user- d at a p ort ion , and t h e fr am e check net w or kin g p rof essionals, r egar dless of ex pert ise. seq uence ( FCS) . Th e addr ess ar ea, w h ich is 2 by t es in leng t h, is com pr ised of 10 bit s r ep r esent ing t he act u al circuit ident ifier an d 6 bit s of field s r elat ed t o cong est ion m anagem ent . Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e This id en t if ier com m only is r efer r ed t o as t he d at a- link connect ion id en t ifier ( DLCI ) . Each of har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on t hese is discussed in t he descript ion s t hat follow . a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy

Standard Frame Relay Frame

  syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease St and ard Fr am e Relay fr am es con sist of t he f ields illust r at ed in Figur e 10 - 4 . pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s. The f ollow in g d escr ipt ions sum m ar ize t he b asic Fr am e Relay fr am e fields illust r at ed in Figur e 10 - 4 .

  LMI Frame Format

  Forw ar d- ex plicit congest ion not ificat ion ( FECN)

  — Ensur es t he in t eg r it y of t r ansmit t ed dat a. This v alue is com put ed by t h e sour ce device and v er ified by t h e r eceiver t o en su r e int egr it y of t r ansm ission.

  Fra m e Che ck Se qu en ce

  — Cont ains en cap su lat ed u pper - layer dat a. Each fr am e in t his v ariab le- lengt h f ield includes a user dat a or pay load f ield t h at w ill v ary in lengt h u p t o 16 , 000 oct et s. This field ser v es t o t r an sp ort t he higher - layer p rot ocol packet ( PDU) t hr ou gh a Fr ame Relay n et wor k .

  D a t a

  a v alue of 1 b y a sw it ch , ind icat es t h at cong est ion w as ex per ien ced in t he net w or k in t he dir ect ion opposit e of t h e fr am e t r ansm ission fr om sour ce t o d est inat ion . Discard elig ibilit y ( DE) is set by t he DTE dev ice, such as a rou t er , t o ind icat e t h at t he m ar ked fr am e is of lesser imp or t ance r elat iv e t o ot her fr am es being t r ansmit t ed . Fram es t h at ar e m ar ked as " discard eligible" shou ld be discar ded befor e ot h er fr am es in a congest ed n et wor k . Th is allow s f or a basic pr iorit izat ion m echan ism in Fr ame Relay net w or ks.

  Backw ar d- ex plicit congest ion not ificat ion ( BECN) is a single- bit field t h at , w hen set t o

  is a single- bit field t h at can be set t o a v alue of 1 by a sw it ch t o in dicat e t o an end DTE dev ice, such as a r out er , t h at congest ion was ex per ien ced in t he dir ect ion of t he fr am e t r ansm ission f r om sour ce t o dest inat ion. The pr im ar y benefit of t he use of t h e FECN and BECN fields is t h e capabilit y of hig her- lay er pr ot ocols t o r eact int elligent ly t o t hese con gest ion indicat or s. Today , DECnet and OSI ar e t h e only hig her- lay er pr ot ocols t hat im plem ent t hese capabilit ies.

  — Cont ains t he f ollow ing inf or mat ion :

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Ad dre ss

  01 111 110 .

  • D LCI — The 10 - bit DLCI is t he essence of t h e Fram e Relay h ead er . Th is value r ep r esent s t h e v ir t u al connect ion b et ween t he DTE d ev ice and t he sw it ch. Each v irt u al connect ion t hat is mu lt iplex ed ont o t he ph ysical chann el w ill be r ep r esent ed by a un iq ue D LCI . Th e DLCI valu es hav e local sign ificance only , w hich means t hat t hey ar e un iq ue on ly t o t h e phy sical ch annel on w hich t hey r eside. Th er efor e, dev ices at opp osit e end s of a conn ect ion can u se diff er ent DLCI v alu es t o r efer t o t he sam e v irt u al connect ion.
  • Ex t en de d A ddre ss ( EA) — The EA is used t o indicat e w h et h er t he by t e in w hich t he EA v alue is 1 is t h e last add ressin g f ield . I f t he v alue is 1 , t hen t he cur r ent by t e is det er min ed t o be t h e last DLCI oct et . Alt houg h cu rr ent Fr am e Relay im plement at ion s all use a t w o- oct et DLCI , t his capab ilit y does allow longer DLCI s t o be used in t h e fu t ur e. The eigh t h bit of each b yt e of t he Ad dr ess f ield is used t o ind icat e t h e EA.
  • C/ R— The C/ R is t h e bit t hat follow s t he m ost sign ificant DLCI by t e in t he Ad dr ess field. Th e C/ R bit is not cu r rent ly d ef ined.
  • Conge st ion Con t rol— This consist s of t he 3 bit s t hat con t rol t he Fr am e Relay congest ion- not if icat ion m ech anisms. Th ese ar e t h e FECN, BECN, and DE b it s, w h ich ar e t he last 3 b it s in t he Add r ess f ield.
    • Table of Content s
    • I ndex

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  Figur e 10 - 5 .

  The f ollow in g d escr ipt ions sum m ar ize t he f ield s illu st r at ed in Figur e 10 - 5 .

  Fla g — Delim it s t h e beginn in g and en d of t he fr am e. LM I D LCI — I d en t ifies t he f r ame as an LMI f r ame in st ead of a basic Fr am e Relay fr am e.

  • I ndex

  Table of Content s The LMI - specif ic DLCI valu e defined in t he LMI consort iu m specif icat ion is DLCI = 102 3.

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion U nnum be re d I nf orm at i on I ndi ca t or — Set s t he poll/ f inal b it t o zer o.

  By Cisco Systems, Inc.

  P rot ocol Di scr im in at or

  — Alw ay s cont ains a v alue ind icat ing t h at t h e fr am e is an LMI fr am e.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003 Cal l Re fe re nce — Alw ay s cont ains zer os. This field cur r en t ly is not used f or any pur pose.

  I SBN: 1- 58 705 -1 19 -2 Me ssa ge Ty p

  e— Labels t he fr am e as one of t he f ollow ing m essage t yp es:

  Pages: 11 28

  • St a t us- i nqu ir y m essage — Allow s a user device t o inqu ir e ab out t he st at us of t he net w or k.
  • St a t us m e ssa ge — Resp onds t o st at us- inq uir y messages. St at us m essag es in clud e The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of k eepaliv es and PVC st at u s m essages.

  essent ial an d cu t t ing- edg e t ech nologies.

  I nf orm a t ion Ele m en t s

  — Cont ains a v ar iab le num b er of in divid ual inf or mat ion elem ent s Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ( I Es) . I Es con sist of t he follow ing fields: nov ice t o ex pert .

  • I E I den t if ie r— Un iq uely ident ifies t he I E. New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP - I E Len gt h— I n dicat es t he lengt h of t h e I E.

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age - D a t a— Consist s of 1 or m ore by t es con t aining en capsulat ed u pper - layer d at a. Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat Fra m e Che ck Se qu en ce ( FCS) — Ensur es t he in t eg r it y of t r ansmit t ed dat a.

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary

  Fram e Relay is a net w or king p rot ocol t hat wor k s at t he b ot t om t w o lev els of t he OSI refer ence m odel: t h e phy sical and dat a lin k layer s. I t is an exam p le of packet - sw it ch ing t ech nology , w hich enables end st at ions t o dy nam ically shar e n et w or k r esou rces.

  • Table of Content s
  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  I ndex

  Fram e Relay d ev ices f all int o t he f ollow in g t wo gener al cat egor ies:

  Dat a t erm inal eq uipm ent ( DTEs) , w hich include t er m inals, person al comp ut er s, rou t er s, and br idg es

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  Dat a cir cuit - t er m in at ing equipm ent ( DCEs) , w hich t r ansm it t he dat a t hr oug h t he n et w or k and ar e of t en car rier - ow ned d ev ices ( alt houg h, incr easing ly , ent er pr ises are b uy ing t heir

  I SBN: 1- 58 705 -1 19 -2

  ow n DCEs and imp lem ent ing t h em in t h eir n et wor k s)

  Pages: 11 28

  Fram e Relay n et w or k s t r ansfer d at a u sing on e of t he f ollow ing t w o con nect ion t y pes: Sw it ched v ir t ual cir cu it s ( SVCs) , w hich ar e t emp orar y conn ect ions t hat are cr eat ed f or each

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of dat a t r ansfer an d t h en ar e t er m in at ed w h en t he dat a t ran sf er is comp let e ( not a w idely essent ial an d cu t t ing- edg e t ech nologies. used con nect ion ) Perm an en t v irt ual cir cu it s ( PVCs) , w hich are perm anent connect ions Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom The D LCI is a v alue assig ned t o each v ir t ual cir cu it and D TE d ev ice con nect ion p oin t in t he Fr am e nov ice t o ex pert . Relay WAN. Tw o diff er ent con nect ion s can be assig ned t he sam e valu e w it hin t he sam e Fr am e

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Relay WAN—one on each side of t he v irt ual conn ect ion. Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  I n 199 0, Cisco Sy st em s, St r at aCom , Nor t h er n Telecom , and Digit al Equ ip m en t Cor por at ion dev elop ed a set of Fr am e Relay en hancem en t s called t he Local Manag em ent I nt erf ace ( LMI ) . The Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . LMI en hancem en t s off er a n um ber of feat u res ( r efer red t o as ex t ensions) f or m anagin g com plex int er net w ork s, includ in g t he f ollow ing :

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing Global addr essing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, Vir t ual cir cu it st at us messages and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all Mu lt icast ing net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Review Questions 1 :

  What k ind of t echn ology is Fr ame Relay ?

  • Table of Content s

  2 : I ndex

  Nam e t he t wo k in ds of p ack et - swit chin g t echn iq ues discussed in t his chapt er , and

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion br iefly describe each.

  By Cisco Systems, Inc.

  3 : Descr ibe t he dif fer en ce b et ween SVCs and PVCs.

  Pub lish er: Cisco Press 4 :

  What is t h e dat a- link conn ect ion ident ifier ( D LCI ) ?

  Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 5 : Descr ibe h ow LMI Fram e Relay d if fer s f rom basic Fr am e Relay .

  Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 11. High-Speed Serial Interface Obj e ct i ve s Table of Content s • Discuss t he h ist or y an d st an dar ds of HSSI . I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Ex plain t he t echn ical specificat ions of HSSI . By Cisco Systems, Inc. Descr ibe t he benef it s of em ploy ing HSSI t echnology . Pub lish er: Cisco Press Discuss how HSSI operat es. Pub Dat e: Sep tem ber 1 1, 2 003 I SBN: 1- 58 705 -1 19 -2 Pages: 11 28 The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies. Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction

  The High - Speed Ser ial I nt er face ( HSSI ) is a DTE/ DCE int er face t hat w as dev elop ed by Cisco Sy st em s and T3 plus Net w or king t o add ress t he n eed for high- sp eed com m un icat ion ov er WAN link s. The HSSI specificat ion is av ailable t o any or gan izat ion w ant in g t o im plement HSSI .

  • Table of Content s
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

HSSI Interface Basics

  HSSI def in es bot h elect r ical and phy sical in t erf aces on DTE an d D CE devices. I t oper at es at t h e ph ysical layer of t h e OSI r efer en ce mod el.

  • Table of Content s HSSI t echnical char act er ist ics are su mm ar ized in Table 1 1- 1 .
  • I ndex

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  

Tab le 1 1 - 1 . HSSI Te chn ical Cha r act er i st ics

Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  Cha ra ct e ri st ic V a lue

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  Max im um signaling r at e

  52 Mb ps Max im um cable lengt h 50 f eet Num ber of conn ect or p oint s

  50 I nt er face DTE- DCE The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Elect rical t echnolog y Dif ferent ial ECL Ty pical pow er consum pt ion 61 0 m W

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom Topology Point - t o- point nov ice t o ex pert .

  Cab le t yp e Shielded t wist ed- p air wir e New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  The m ax im um signaling r at e of HSSI is 5 2 Mbps. At t his r at e, HSSI can hand le t he T3 speeds Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et . ( 45 Mb ps) of m any of t oday 's f ast WAN t echn ologies, as w ell as t he Of fice Ch annel- 1 ( OC- 1 ) speed s ( 52 Mb ps) of t h e syn ch ron ous dig it al hier archy ( SDH) . I n addit ion, HSSI easily can

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat pr ov ide hig h- speed conn ect iv it y bet w een LANs, such as Tok en Ring an d Et her net .

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing The u se of diff er ent ial em it t er- cou pled logic ( ECL) helps HSSI ach iev e high dat a r at es and low indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . noise levels. ECL h as been u sed in Cray com pu t er sy st em int er faces for y ear s and is specif ied by Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, t he ANSI Hig h- Per for m ance Par allel I nt er face ( HI PPI ) com m unicat ions st an dar d f or and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all super comp ut er LAN com m un icat ion s. ECL is an off - t he- shelf t echn ology t hat per m it s ex cellent net w or kin g p rof essionals, r egar dless of ex pert ise. r et im ing on t he receiv er, result ing in reliable t im ing m arg ins.

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e HSSI uses a su bm in iat ur e, FCC- app r oved 50- p in conn ect or t hat is sm aller t han it s V. 35 har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on count er par t . To r ed uce t he n eed for male- m ale and fem ale- female ad apt er s, HSSI cab le a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions connect or s ar e sp ecif ied as m ale. The HSSI cable u ses t h e sam e n um ber of pin s and w ires as t he t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

  Sm all Com pu t er Syst em s I nt erf ace 2 ( SCSI - 2) cab le, b ut t he HSSI elect r ical specif icat ion is m or e Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy concise. syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

HSSI Operation

  The f lex ibilit y of t h e HSSI clock an d d at a- sig naling pr ot ocol m ak es u ser ( or vend or) ban dw idt h allocat ion possible. The D CE con t r ols t he clock by chan ging it s speed or b y delet in g clock pu lses. I n t his w ay , t he D CE can allocat e ban dw idt h bet w een app licat ions. For ex amp le, a PBX m ay

  • Table of Content s

  r eq uir e a p art icular am ou nt of b andw idt h, a rou t er anot h er am ou nt , an d a chann el ex t ender a

  • I ndex

  t hir d am ount . Bandw idt h allocat ion is k ey t o mak ing T3 and ot her b road band serv ices af for dab le

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion and pop ular .

  By Cisco Systems, Inc.

  HSSI assum es a peer- t o- peer in t elligence in t he DCE and DTE. The cont r ol pr ot ocol is sim p lif ied , w it h just t w o cont r ol sign als requ ired ( " DTE av ailab le" and " DCE av ailable" ) . Bot h sig nals m ust

  Pub lish er: Cisco Press

  be assert ed befor e t h e dat a cir cuit can b ecom e v alid . The D CE and DTE ar e ex pect ed t o be

  Pub Dat e: Sep tem ber 1 1, 2 003

  capable of m anag ing t he n et w or k s behind t h eir in t er f aces. Redu cin g t h e nu mb er of con t rol

  I SBN: 1- 58 705 -1 19 -2 signals im pr ov es cir cuit r eliab ilit y by r ed ucing t he n um ber of circuit s t hat can f ail. Pages: 11 28

Loopback Tests

  HSSI pr ov ides fou r loopback t est s, w hich ar e illust r at ed in Figur e 11 - 1 . Th e fir st pr ov ides a local The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of cable t est as t h e signal loop s back af t er it r eaches t h e DTE por t . Th e second t est r each es t he line essent ial an d cu t t ing- edg e t ech nologies. por t of t he local DCE. Th e t hir d t est reaches t he lin e por t of t he r em ot e DCE. Fin ally , t h e fou rt h t est is a DCE- in it iat ed t est of t h e DTE' s DCE p ort .

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

  

Figu r e 1 1 - 1 . H SSI Su ppor t s Four Loopba ck Te st s

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Summary

  HSSI is an int er face t echnology t hat was developed by Cisco Sy st em s an d T3 plus Net w or kin g in t he lat e 199 0s t o fill t h e need f or a high- speed dat a com m un icat ion solu t ion ov er WAN lin ks. I t uses dif ferent ial em it t er - coupled log ic ( ECL) , w hich pr ovid es h igh- speed dat a t ran sf er w it h low

  Table of Content s •

  noise levels. HSSI pin connect ors are sign ificant ly sm aller t h an p in conn ect or s f or comp et in g

  I ndex •

  t echnologies. The HSSI cable u ses t h e same num ber of p in s and w ir es as t he Sm all Com p ut er

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  Sy st em s I nt er face 2 ( SCSI - 2) cable, but it s elect r ical specif icat ion is m or e con cise. HSSI m ak es By ban dw idt h r esour ces easy t o allocat e, m ak ing T3 and ot her br oad band ser v ices av ailable and Cisco Systems, Inc. aff or dable. HSSI r equir es t he p resence of only t w o con t rol sig nals, m aking it highly r eliable because t her e ar e few er cir cuit s t h at can fail. HSSI p er f orm s f our loop back t est s for r eliabilit y .

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Review Questions 1 : Nam e at least t h r ee b en ef it s of im plem ent in g HSSI t echn olog y in a net w or k.

  Table of Content s • 2 : I ndex Nam e t he f our loop back t est s t hat HSSI per for m s.

  • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Chapter 12. Integrated Services Digital Network Table of Content s Obj e ct i ve s

  • I ndex •

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion Ex plain w hat I SD N is.

  By Cisco Systems, Inc.

  Descr ibe I SDN devices and how t hey oper at e.

  Pub lish er: Cisco Press

Pub Dat e: Sep tem ber 1 1, 2 003 Descr ibe t he specif icat ion s for I SD N dat a t r ansm it t al for t he t h ree lay ers at w hich I SD N

  t r ansm it s.

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Introduction

  I n t egrat ed Serv ices Digit al Net w or k ( I SDN)

  is com pr ised of dig it al t elep hony an d d at a- t r anspor t ser v ices of fer ed by region al t elep hone car r ier s. I SDN inv olv es t he dig it izat ion of t h e t eleph one net w or k, w hich p er m it s v oice, d at a, t ext , gr aph ics, m usic, vid eo, and ot her sour ce m at er ial t o be

  • Table of Content s

  t r ansm it t ed ov er exist ing t elep hone w ir es. Th e emer gence of I SDN r epr esent s an ef for t t o

  • I ndex

  st andar d ize su bscr iber serv ices, u ser / net w or k int er faces, an d net w ork an d in t ern et w or k

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  capabilit ies. I SDN app licat ions in clud e high - speed im age app licat ions ( su ch as Grou p I V By facsim ile) , ad dit ional t elephon e lin es in h omes t o ser v e t he t elecomm ut in g in dust r y , high - speed Cisco Systems, Inc. file t r an sf er , an d videoconf er encing. Voice serv ice is also an applicat ion f or I SDN. Th is ch apt er sum m arizes t h e und er ly ing t echn ologies and ser v ices associat ed w it h I SDN.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

ISDN Devices

  I SDN d ev ices in clu de t er min als, t er m inal ad apt ers ( TAs) , net w ork - t er m in at ion devices, line- t er min at ion equ ip m en t , and exchan ge- t erm inat ion equip ment . I SDN t er m in als com e in t w o t y pes. Specialized I SDN t erm inals ar e r efer red t o as t erm inal eq uipm ent t yp e 1 ( TE1) . Non- I SDN

  • Table of Content s

  t er min als, such as DTE, t hat pr edat e t h e I SDN st and ar ds ar e r ef err ed t o as t er m inal equ ip m en t

  I ndex • t y pe 2 ( TE2 ) . TE1 s connect t o t he I SD N net w or k t hr oug h a fou r - wir e, t w ist ed - pair d ig it al link .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  TE2 s connect t o t he I SDN net w or k t hr oug h a TA. The I SDN TA can be eit her a st andalone d ev ice By or a boar d in sid e t he TE2. I f t he TE2 is imp lem ent ed as a st an dalone dev ice, it connect s t o t he Cisco Systems, Inc. TA v ia a st andar d ph ysical- lay er int er face. Ex am ples in clu de EI A/ TI A- 23 2- C ( for m erly RS- 232 - C) , V.2 4, an d V. 3 5.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  Beyon d t he TE1 and TE2 d ev ices, t h e nex t conn ect ion point in t he I SDN n et wor k is t h e net w or k

  I SBN: 1- 58 705 -1 19 -2

  t er min at ion t y pe 1 ( NT1 ) or n et wor k t er m inat ion t yp e 2 ( NT2) device. These are net w ork -

  Pages: 11 28

  t er min at ion d ev ices t hat conn ect t he f our - w ir e su bscr iber w ir ing t o t h e conv en t ional t w o- w ir e local loop. I n Nor t h Am er ica, t he NT1 is a cust om er pr em ises equipm ent ( CPE) dev ice. I n m ost ot her p art s of t he w or ld, t he NT1 is par t of t he net w or k pr ov ided b y t he car r ier . Th e NT2 is a m or e com p licat ed device t hat t y pically is foun d in dig it al pr ivat e br anch ex chang es ( PBXs) and t hat per for m s Lay er 2 and 3 pr ot ocol fu nct ions an d concent r at ion ser v ices. An NT1/ 2 device also exist s as a sin gle dev ice t hat com bin es t he f unct ions of an NT1 and an NT2. The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  I SDN specifies a n um ber of r ef erence p oin t s t hat def in e logical int er faces bet w een fu nct ional gr oup s, su ch as TAs and NT1s. I SDN r efer en ce point s in clud e t he follow in g: Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert .

  R — The r eference p oin t b et ween non- I SDN eq uipm ent and a TA.

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  S — The r eference p oin t b et ween user t er m inals and t h e NT2.

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  T — The r eference p oin t b et ween NT1 an d NT2 dev ices.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  U

  — The r eference p oin t b et ween NT1 d ev ices an d lin e- t er m in at ion eq uipm ent in t h e car r ier net w or k. The U r efer en ce point is relevan t on ly in Nor t h Am er ica, w here t he NT1 fu nct ion is

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat not pr ov ided b y t he car r ier n et wor k .

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing

  Figur e 12 - 1 illust r at es a sam ple I SDN con figu rat ion and show s t h r ee d ev ices at t ach ed t o an indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent .

  I SDN sw it ch at t he cent r al off ice. Tw o of t h ese d ev ices ar e I SDN- com pat ible, so t hey can b e Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, at t ached t hr oug h an S ref er ence point t o NT2 d ev ices. Th e t hir d device ( a st an dar d, n on- I SDN and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all t elep hone) at t ach es t hr oug h t h e r ef erence poin t t o a TA. Any of t hese dev ices also could at t ach net w or kin g p rof essionals, r egar dless of ex pert ise. t o an NT1 / 2 device, w hich w ould r eplace bot h t he NT1 and t h e NT2. I n add it ion , alt hou gh t hey ar e not show n, sim ilar user st at ion s ar e at t ached t o t h e far - r ight I SDN sw it ch.

  Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy .

Figu r e 1 2 - 1 . Sam pl e I SDN Conf ig ur a t ion I ll ust r a t e s Re la t i onshi ps

  Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich Be t w ee n De vi ce s an d Ref e r en ce Poin t s pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  Table of Content s • I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

Services

  Ther e ar e t w o t y pes of serv ices associat ed w it h I SDN:

  • Table of Content s

  BRI

  • I ndex

  PRI

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

ISDN BRI Service

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  The I SDN Basic Rat e I nt er face ( BRI ) ser v ice of fer s t w o B chann els an d on e D ch annel ( 2 B+ D ) .

  I SBN: 1- 58 705 -1 19 -2

  BRI B- ch annel serv ice oper at es at 64 k bp s and is m ean t t o carr y u ser d at a; BRI D- chann el

  Pages: 11 28

  ser v ice operat es at 16 k bps and is m ean t t o car r y cont r ol an d sign alin g in for m at ion, alt h ough it can su ppor t user dat a t ran sm ission un der cer t ain cir cum st ances. The D channel sign alin g pr ot ocol com pr ises Layer s 1 t hr oug h 3 of t h e OSI r efer en ce m od el. BRI also pr ov id es for f r amin g cont r ol an d ot h er over head, b r in ging it s t ot al bit r at e t o 19 2 kb ps. The BRI phy sical layer specif icat ion is I nt er nat ional Telecomm u nicat ion Union– Telecom m un icat ion s St andar d s Sect ion The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of ( I TU- T) ( f orm er ly t he Consult at ive Com m it t ee f or I nt er nat ional Telegr aph and Telep hone essent ial an d cu t t ing- edg e t ech nologies. [ CCI TT] ) I . 430 .

Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom ISDN PRI Service nov ice t o ex pert

  New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP

  I SDN Pr im ar y Rat e I nt er face ( PRI ) ser v ice of fer s 23 B ch annels and 1 D ch annel in Nor t h Am er ica an d Jap an, y ield ing a t ot al bit r at e of 1 . 544 Mb ps ( t h e PRI D chann el ru ns at 64 k bps) .

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age

  I SDN PRI in Eur ope, Aust r alia, and ot h er par t s of t he w or ld pr ov id es 30 B chann els plus on e 64- k bps D chan nel and a t ot al int er face r at e of 2. 0 48 Mbp s. The PRI phy sical lay er specif icat ion is Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I TU- T I .4 31.

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  ISDN Specifications This sect ion d escrib es t he v ar iou s I SDN specificat ions f or Lay er 1, Layer 2 , and Lay er 3.

  • Table of Content s

Layer 1

  I ndex • I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion

  I SDN p hy sical lay er ( Lay er 1) fr am e for m at s d if fer d ep en ding on w het her t he f r am e is out bou nd By Cisco Systems, Inc. ( f rom t er m inal t o net w or k) or inb ound ( f r om net w or k t o t er m inal) . Bot h ph ysical layer int er faces ar e show n in Figur e 12 - 2 .

  Pub lish er: Cisco Press Pub Dat e: Sep tem ber 1 1, 2 003

  I SBN: 1- 58 705 -1 19 -2 Pages: 11 28

Figu r e 1 2 - 2 . I SD N Ph y si cal Lay er Fr a m e For m a t s D if fe r D ep en din g on

The ir Di r ect ion

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of essent ial an d cu t t ing- edg e t ech nologies.

  Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom nov ice t o ex pert . New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er n et .

  I n t ern et w or k in g Tech nologies Hand book , Four t h Ed it ion , is a com pr ehensive refer ence t hat

  enables net w or kin g p r ofessionals t o un derst and an d im plem en t cont em por ar y int er net w ork ing t echnologies. Mast er t he t er m s, con cep t s, t echn ologies, an d devices used in t oday ' s net w ork ing indu st ry . Lear n how t o incor por at e int er net w or kin g t echn olog ies in t o a LAN/ WAN env ir onm ent . Com plet e w it h new an d u pdat ed chapt er s on secur it y , st or age, opt ical net w or k in g, scalabilit y, and speed, t h is book is a com plet e an d u p- t o- d at e r ef er ence t o t he t op ics t hat are essen t ial t o all net w or kin g p rof essionals, r egar dless of ex pert ise. Reader s w ill obt ain a g reat er un der st an ding of LAN and WAN n et w or k ing, p ar t icu lar ly t h e har dw ar e, pr ot ocols, and ser v ices inv olv ed . Fu ndam ent al t ech nology inf or mat ion is pr ov ided on a b r oad r ang e of int egr al sy st em s and serv ices, in clud ing det ailed descr ipt ion s, rev iew quest ions t o en su re con cept comp r eh en sion and r et en t ion, and ad dit ional r esou r ces f or fu rt her st udy . Cov erag e is also ext end ed n ot only t o new n et wor k ing concep t s, but also t o old er , legacy The f r am es ar e 4 8 b it s long, of w hich 3 6 b it s r ep resen t d at a. The bit s of an I SD N ph ysical lay er syst em s, pr ovid in g a m or e r ealist ic pict ur e of t he real- w or ld n et w or k ing en vir onm ent s in w hich fr am e ar e used as follow s: pr of essionals oper at e. Tools and gu id elines f or opt im izing syst em per for m ance w ill incr ease pr odu ct iv it y an d im pr ov e eff iciency, help ing t he r eader m ake mor e in t elligent , cost - eff icient decisions for t h eir net w ork s.

  F — Prov ides syn chr onizat ion L

  — Adju st s t he av erag e bit valu e

  A

  — Act iv at es dev ices

  S

  — I s unassig ned

  B1 , B2

  , an d D — Handle user dat a Mu lt ip le I SD N user dev ices can be ph ysically at t ach ed t o one cir cu it . I n t his conf ig ur at ion, collisions can r esult if t w o t er min als t ran smit sim ult an eou sly . Th er efor e, I SDN p rov ides f eat u res

  • Table of Content s

  t o det er m ine link cont en t ion. Wh en an NT r eceiv es a D bit f r om t he TE, it echoes b ack t he bit in

  I ndex • t he next E- b it posit ion. Th e TE ex pect s t h e next E bit t o b e t he sam e as it s last t ran sm it t ed D b it .

  I nt e rn et w or k ing Te chnologie s H a ndbook , Four th Edit ion By Cisco Systems, Inc.

  Term inals cann ot t ran sm it in t o t h e D ch annel u nless t hey fir st det ect a sp ecific n um ber of ones ( ind icat ing " n o signal" ) cor r esp ondin g t o a p re- est ablish ed p rior it y . I f t he TE det ect s a b it in t he ech o ( E) chan nel t hat is dif ferent f rom it s D b it s, it m ust st op t r ansm it t ing im mediat ely . This

  Pub lish er: Cisco Press

  simp le t ech nique ensu res t h at on ly one t er min al can t r an sm it it s D m essag e at on e t im e. Aft er

  Pub Dat e: Sep tem ber 1 1, 2 003

  successful D- m essage t ran sm ission , t he t er m inal h as it s pr ior it y r ed uced by requ ir ing it t o d et ect

  I SBN: 1- 58 705 -1 19 -2

  m or e con t inuou s ones bef ore t ran sm it t ing . Term inals can not r aise t heir pr ior it y un t il all ot her

  Pages: 11 28

  dev ices on t he sam e line h ave had an op por t un it y t o send a D m essage. Telep hone con nect ion s hav e hig her pr ior it y t han all ot h er ser vices, and sig naling in for m at ion has a higher p rior it y t h an non sig naling in for m at ion.

  The u pdat ed edit ion of t he b est - selling all- in- one net w ork ing r ef erence p rov ides cover age of

  Layer 2 essent ial an d cu t t ing- edg e t ech nologies.

  Lay er 2 of t he I SDN sig naling pr ot ocol is Link Access Procedur e, D chann el ( LAPD) . LAPD is similar t o High- Lev el Dat a Link Cont r ol ( HD LC) and Link Access Procedur e, Balanced ( LAPB) ( see Con cise ov er v iew s of t echn olog ies essen t ial t o n et wor k ing pr ofession als at all lev els, f rom

  

Ch apt er 16 , " Sy nchr onou s Dat a Link Cont r ol an d D er iv at ives," and Ch apt er 17 , " X. 25 , " f or m ore

nov ice t o ex pert .

  inf orm at ion on t hese pr ot ocols) . As t he ex pansion of t he LAPD acr ony m ind icat es, t his lay er is used acr oss t he D chan nel t o en su re t hat con t rol and sig naling inf orm at ion flow s an d is r eceiv ed New chapt er s include cov erag e of im por t ant t opics like VoI P and EAP pr oper ly. The LAPD f ram e f or mat ( see Figur e 12 - 3 ) is ver y sim ilar t o t hat of HDLC; like HDLC,

  Cov erag e of cut t ing edge t echn ologies lik e opt ical n et wor k ing and st or age LAPD uses super visor y, infor m at ion, an d unn um bered fr am es. The LAPD pr ot ocol is f or mally specif ied in I TU- T Q. 920 and I TU- T Q. 9 21.

  Aut h ored by Cisco Sy st ems, w or ldw ide leader in net w or king f or t he I n t er