27596087 networking training report

8/13/2019 27596087 Networking Training Report

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Swami Parmanand College Of Engg. & TechnologyLalru (Punjab)

SUMITTED TO : SUBMITTED BY:Head of Department PRABHJOT CHAHAL

Electr cal ! Electron c" En##$ ROLL %O:L&'()'('()*+ ELECTRICAL ! ELECTRO%ICS E%,,$


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Pra618ot C1a1al

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COMPANY PROFILE

Established in March 1988, as a Scientific Society of theDepartment of Information Technology , Ministry ofCommunication s and Information Technology , o!ernment of India, The Centre for Development ofAdvanced Computing (C-DAC) , is primarily an " # D institution in!ol!ed in the design, de!elopment and deployment ofad!anced Information Technology $IT% based solutions&

In a little o!er a decade since inception, C'D(C has de!elopedand supplied a range of high performance parallel computers,

)no*n as the PARAM series of supercomputers& C'D(C+s de!elopment acti!ities in this area ha!e beenmission oriented and dri!en by its mission ob ecti!es, both in technology and application de!elopments&

C'D(C, as a result of its pioneering de!elopments, e!ol!ed theraphics and Intelligence based Script Technology $ GIST %, *ith a

!ie* to e-tend the benefits of Information Technology to the !ast and di!ersified multilingual population of India&

.!er the years, C'D(C has di!ersified its acti!ities to addressre/uirements in !arious areas, conse/uently, our e-pertisealso e-tends to other ad!anced areas of InformationTechnology, enabling IT based solutions &

CONTENTS

NET O!"#N$
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OS# %O EL P!OTOCOLS %'C ' !ESS L'N ( LOC'L '!E' NET O!" ) 'N ( # E '!E' NET O!" ) ET E!NET TEC NOLO$#ES NET O!"#N$ C' LE #NTE!NET P!#TOCOLS #P ' !ESS COLO! CO E ST'N '! *L'N (*#!T+'L LOC'L '!E' NET O!") ,!'%E !EL'-

NETW RKING' networking i a collec/ion of indi0idual ne/wor1 2 connec/ed by in/ermedia/e ne/wor1ing de0ice 2/ha/ func/ion a a ingle large ne/wor1. #n/erne/wor1ing refer /o /he indu /ry2 3roduc/ 2 and

3rocedure /ha/ mee/ /he challenge of crea/ing and admini /ering in/erne/wor1 . ,igure 454 illu /ra/e ome


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differen/ 1ind of ne/wor1 /echnologie /ha/ can be in/erconnec/ed by rou/er and o/her ne/wor1ingde0ice /o crea/e an in/erne/wor1.

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The fir / ne/wor1 were /ime5 haring ne/wor1 /ha/ u ed mainframe and a//ached /erminal . Suchen0ironmen/ were im3lemen/ed by bo/h # %6 Sy /em Ne/wor1 'rchi/ec/ure (SN') and igi/al6ne/wor1 archi/ec/ure.Local-area networks (LANs) e0ol0ed around /he PC re0olu/ion. L'N enabled mul/i3le u er in arela/i0ely mall geogra3hical area /o e7change file and me age 2 a well a acce hared re ource ucha file er0er and 3rin/er .Wide-area networks (WANs) in/erconnec/ L'N wi/h geogra3hically di 3er ed u er /o crea/econnec/i0i/y. Some of /he /echnologie u ed for connec/ing L'N include T42 T82 'T%2 #S N2 ' SL2,rame !elay2 radio lin1 2 and o/her . New me/hod of connec/ing di 3er ed L'N are a33earinge0eryday. Today2 high5 3eed L'N and wi/ched in/erne/wor1 are becoming widely u ed2 largely

becau e /hey o3era/e a/ 0ery high 3eed and u33or/ uch high5bandwid/h a33lica/ion a mul/imedia and0ideoconferencing.#n/erne/wor1ing e0ol0ed a a olu/ion /o /hree 1ey 3roblem 9 i ola/ed L'N 2 du3lica/ionof re ource 2 and a lac1 of ne/wor1 managemen/. # ola/ed L'N made elec/ronic communica/ion be/weendifferen/ office or de3ar/men/ im3o ible. u3lica/ion of re ource mean/ /ha/ /he ame hardware andof/ware had /o be u33lied /o each office or de3ar/men/2 a did e3ara/e u33or/ /aff. Thi lac1 ofne/wor1 managemen/ mean/ /ha/ no cen/rali:ed me/hod of managing and /rouble hoo/ing ne/wor1e7i /ed.

Open System Interconnection ReferenceModel

The O3en Sy /em #n/erconnec/ion (OS#) reference model describes how information from asoftware application in one computer moves through a network medium to asoftware application in another computer. The OSI reference model is a conceptual


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model composed of seven layers, each specifying particular network functions. Themodel was developed by the International Organization for Standardization (ISO in!"#$, and it is now considered the primary architectural model for intercomputercommunications. The OSI model divides the tasks involved with moving informationbetween networked computers into seven smaller, more manageable task groups. %task or group of tasks is then assigned to each of the seven OSI layers. &ach layer isreasonably self'contained so that the tasks assigned to each layer can beimplemented independently. This enables the solutions offered by one layer to beupdated without adversely affecting the other layers. The following list details theseven layers of the Open System Interconnection (OSI reference model

Characteristics of the OSI LayersThe e0en layer of /he OS# reference model can be di0ided in/o /wo ca/egorie 9 u33er layer and lowerlayer . The upper layers of /he OS# model deal wi/h a33lica/ion i ue and generally are im3lemen/edonly in of/ware. The highe / layer2 /he a33lica/ion layer2 i clo e / /o /he end u er. o/h u er anda33lica/ion layer 3roce e in/erac/ wi/h of/ware a33lica/ion /ha/ con/ain a communica/ion com3onen/.The /erm u33er layer i ome/ime u ed /o refer /o any layer abo0e ano/her layer in /he OS# model. Thelower layer of /he OS# model handle da/a /ran 3or/ i ue . The 3hy ical layer and /he da/a lin1 layerare im3lemen/ed in hardware and of/ware. The lowe / layer2 /he 3hy ical layer2 i clo e / /o /he 3hy icalne/wor1 medium (/he ne/wor1 cabling2 for e7am3le) and i re 3on ible for ac/ually 3lacing informa/ion on/he medium.

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ProtocolsThe OS# model 3ro0ide a conce3/ual framewor1 for communica/ion be/ween com3u/er 2 bu/ /he modeli/ elf i no/ a me/hod of communica/ion. 'c/ual communica/ion i made 3o ible by u ing communica/ion

3ro/ocol . #n /he con/e7/ of da/a ne/wor1ing2 a protocol i a formal e/ of rule and con0en/ion /ha/go0ern how com3u/er e7change informa/ion o0er a ne/wor1 medium. ' 3ro/ocol im3lemen/ /hefunc/ion of one or more of /he OS# layer .' wide 0arie/y of communica/ion 3ro/ocol e7i /. Some of /he e 3ro/ocol include L'N 3ro/ocol 2 'N

3ro/ocol 2 ne/wor1 3ro/ocol 2 and rou/ing 3ro/ocol . LAN protocols o3era/e a/ /he 3hy ical and da/a lin1layer of /he OS# model and define communica/ion o0er /he 0ariou L'N media. WAN protocolso3era/e a/ /he lowe / /hree layer of /he OS# model and define communica/ion o0er /he 0ariou wide5areamedia.Routing protocols are ne/wor1 layer 3ro/ocol /ha/ are re 3on ible for e7changing informa/ion

be/ween rou/er o /ha/ /he rou/er can elec/ /he 3ro3er 3a/h for ne/wor1 /raffic. ,inally2 network protocols are /he 0ariou u33er5layer 3ro/ocol /ha/ e7i / in a gi0en 3ro/ocol ui/e. %any 3ro/ocol rely

on o/her for o3era/ion. ,or e7am3le2 many rou/ing 3ro/ocol u e ne/wor1 3ro/ocol /o e7changeinforma/ion be/ween rou/er . Thi conce3/ of building u3on /he layer already in e7i /ence i /hefounda/ion of /he OS# model.

OSI Model and Communication Between Systems#nforma/ion being /ran ferred from a of/ware a33lica/ion in one com3u/er y /em /o a of/warea33lica/ion in ano/her mu / 3a /hrough /he OS# layer . ,or e7am3le2 if a of/ware a33lica/ion in Sy /em' ha informa/ion /o /ran mi/ /o a of/ware a33lica/ion in Sy /em 2 /he a33lica/ion 3rogram in Sy /em 'will 3a i/ informa/ion /o /he a33lica/ion layer (Layer ;) of Sy /em '. The a33lica/ion layer /hen 3a e/he informa/ion /o /he 3re en/a/ion layer (Layer


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OSI Layer Ser!icesOne OS# layer communica/e wi/h ano/her layer /o ma1e u e of /he er0ice 3ro0ided by /he econd layer.The er0ice 3ro0ided by adjacen/ layer hel3 a gi0en OS# layer communica/e wi/h i/ 3eer layer in o/hercom3u/er y /em . Three ba ic elemen/ are in0ol0ed in layer er0ice 9 /he er0ice u er2 /he er0ice

3ro0ider2 and /he er0ice acce 3oin/ (S'P). #n /hi con/e7/2 /he service user i /he OS# layer /ha/re@ue / er0ice from an adjacen/ OS# layer. Theservice provider i /he OS# layer /ha/ 3ro0ide er0ice /o er0ice u er . OS# layer can 3ro0ideer0ice /o mul/i3le er0ice u er . The S'P i a conce3/ual loca/ion a/ which one OS# layer can re@ue / /heer0ice of ano/her OS# layer. ,igure 45= illu /ra/e how /he e /hree elemen/ in/erac/ a/ /he ne/wor1 andda/a lin1 layer .


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OSI Model "hysical LayerThe 3hy ical layer define /he elec/rical2 mechanical2 3rocedural2 and func/ional 3ecifica/ion forac/i0a/ing2 main/aining2 and deac/i0a/ing /he 3hy ical lin1 be/ween communica/ing ne/wor1 y /em .Phy ical layer 3ecifica/ion define charac/eri /ic uch a 0ol/age le0el 2 /iming of 0ol/age change 2

3hy ical da/a ra/e 2 ma7imum /ran mi ion di /ance 2 and 3hy ical connec/or . Phy ical layerim3lemen/a/ion can be ca/egori:ed a ei/her L'N or 'N 3ecifica/ion . ,igure 45; illu /ra/e omecommon L'N and 'N 3hy ical layer im3lemen/a/ion .

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OSI Model $ata Lin% LayerThe da/a lin1 layer 3ro0ide reliable /ran i/ of da/a acro a 3hy ical ne/wor1 lin1. ifferen/ da/a lin1 layer3ecifica/ion define differen/ ne/wor1 and 3ro/ocol charac/eri /ic 2 including 3hy ical addre ing2ne/wor1 /o3ology2 error no/ifica/ion2 e@uencing of frame 2 and flow con/rol. Phy ical addre ing (ao33o ed /o ne/wor1 addre ing) define how de0ice are addre ed a/ /he da/a lin1 layer. Ne/wor1/o3ology con i / of /he da/a lin1 layer 3ecifica/ion /ha/ of/en define how de0ice are /o be 3hy icallyconnec/ed2 uch a in a bu or a ring /o3ology. Error no/ifica/ion aler/ u33er5layer 3ro/ocol /ha/ a/ran mi ion error ha occurred2 and /he e@uencing of da/a frame reorder frame /ha/ are /ran mi//ed ou/of e@uence. ,inally2 flow con/rol modera/e /he /ran mi ion of da/a o /ha/ /he recei0ing de0ice i no/

o0erwhelmed wi/h more /raffic /han i/ can handle a/ one /ime. The #n /i/u/e of Elec/rical and Elec/ronicEngineer (#EEE) ha ubdi0ided /he da/a lin1 layer in/o /wo ublayer 9 Logical Lin1 Con/rol (LLC) and%edia 'cce Con/rol (%'C). ,igure 45A illu /ra/e /he#EEE ublayer of /he da/a lin1 layer.


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1-1&The Logical Link Control (LLC) ublayer of /he da/a lin1 layer manage communica/ion be/weende0ice o0er a ingle lin1 of a ne/wor1. LLC i defined in /he #EEE AB>.> 3ecifica/ion and u33or/ bo/hconnec/ionle and connec/ion5orien/ed er0ice u ed by higher5layer 3ro/ocol . #EEE AB>.> define anumber of field in da/a lin1 layer frame /ha/ enable mul/i3le higher5layer 3ro/ocol /o hare a ingle

3hy ical da/a lin1. The Media Access Control (MAC) ublayer of /he da/a lin1 layer manage 3ro/ocol acce /o /he 3hy ical ne/wor1 medium. The #EEE %'C 3ecifica/ion define %'C addre e 2which enable mul/i3le de0ice /o uni@uely iden/ify one ano/her a/ /he da/a lin1 layer.

OSI Model 'etwor% LayerThe ne/wor1 layer define /he ne/wor1 addre 2 which differ from /he %'C addre . Some ne/wor1 layerim3lemen/a/ion 2 uch a /he #n/erne/ Pro/ocol (#P)2 define ne/wor1 addre e in a way /ha/ rou/e elec/ioncan be de/ermined y /ema/ically by com3aring /he ource ne/wor1 addre wi/h /he de /ina/ion ne/wor1addre and a33lying /he ubne/ ma 1. ecau e /hi layer define /he logical ne/wor1 layou/2 rou/er canu e /hi layer /o de/ermine how /o forward 3ac1e/ . ecau e of /hi 2 much of /he de ign and configura/ionwor1 for in/erne/wor1 ha33en a/ Layer 82 /he ne/wor1 layer.

OSI Model (ransport LayerThe /ran 3or/ layer acce3/ da/a from /he e ion layer and egmen/ /he da/a for /ran 3or/ acro /hene/wor1. $enerally2 /he /ran 3or/ layer i re 3on ible for ma1ing ure /ha/ /he da/a i deli0ered error5freeand in /he 3ro3er e@uence. ,low con/rol generally occur a/ /he /ran 3or/ layer. ,low con/rol manageda/a /ran mi ion be/ween de0ice o /ha/ /he /ran mi//ing de0ice doe no/ end more da/a /han /herecei0ing de0ice can 3roce . %ul/i3le7ing enable da/a from e0eral a33lica/ion /o be /ran mi//ed on/o aingle 3hy ical lin1. *ir/ual circui/ are e /abli hed2 main/ained2 and /ermina/ed by /he /ran 3or/ layer.Error chec1ing in0ol0e crea/ing 0ariou mechani m for de/ec/ing /ran mi ion error 2 while errorreco0ery in0ol0e ac/ing2 uch a re@ue /ing /ha/ da/a be re/ran mi//ed2 /o re ol0e any error /ha/ occur.The /ran 3or/ 3ro/ocol u ed on /he #n/erne/ are TCP and + P.

OSI Model Session LayerThe e ion layer e /abli he 2 manage 2 and /ermina/e communica/ion e ion .Communica/ion e ion con i / of er0ice re@ue / and er0ice re 3on e /ha/ occur be/ween a33lica/ionloca/ed in differen/ ne/wor1 de0ice . The e re@ue / and re 3on e are coordina/ed by 3ro/ocolm3lemen/ed a/ /he e ion layer. Some e7am3le of e ion5layer im3lemen/a/ion include one#nforma/ion Pro/ocol ( #P)2 /he '33leTal1 3ro/ocol /ha/ coordina/e /he name binding 3roce D andSe ion Con/rol Pro/ocol (SCP)2 /he ECne/ Pha e #* e ion layer 3ro/ocol.


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OSI Model "resentation LayerThe 3re en/a/ion layer 3ro0ide a 0arie/y of coding and con0er ion func/ion /ha/ are a33lied /oa33lica/ion layer da/a. The e func/ion en ure /ha/ informa/ion en/ from /he a33lica/ion layer of oney /em would be readable by /he a33lica/ion layer of ano/her y /em. Some e7am3le of 3re en/a/ion layer

coding and con0er ion cheme include common da/a re3re en/a/ion forma/ 2 con0er ion of charac/erre3re en/a/ion forma/ 2 common da/a com3re ion cheme 2 and common da/a encry3/ion cheme .Common da/a re3re en/a/ion forma/ 2 or /he u e of /andard image2 ound2 and 0ideo forma/ 2 enable /hein/erchange of a33lica/ion da/a be/ween differen/ /y3e of com3u/er y /em . Con0er ion cheme areu ed /o e7change informa/ion wi/h y /em by u ing differen/ /e7/ and da/a re3re en/a/ion 2 uch aE C #C and 'SC##. S/andard da/a com3re ion cheme enable da/a /ha/ i com3re ed a/ /he ourcede0ice /o be 3ro3erly decom3re ed a/ /he de /ina/ion. S/andard da/a encry3/ion cheme enable da/aencry3/ed a/ /he ource de0ice /o be 3ro3erly deci3hered a/ /he de /ina/ion. Pre en/a/ion layerim3lemen/a/ion are no/ /y3ically a ocia/ed wi/h a 3ar/icular 3ro/ocol /ac1. Some well51nown /andardfor 0ideo include uic1Time and %o/ion Pic/ure E73er/ $rou3 (%PE$).uic1Time i an '33le Com3u/er 3ecifica/ion for 0ideo and audio2 and %PE$ i a /andard for 0ideo

com3re ion and coding.'mong /he well51nown gra3hic image forma/ are $ra3hic #n/erchange ,orma/ ($#,)2 Foin/Pho/ogra3hic E73er/ $rou3 (FPE$)2 and Tagged #mage ,ile ,orma/ (T#,,). $#, i a /andard forcom3re ing and coding gra3hic image . FPE$ i ano/her com3re ion and coding /andard for gra3hicimage 2 and T#,, i a /andard coding forma/ for gra3hic image .

OSI Model )pplication LayerThe a33lica/ion layer i /he OS# layer clo e / /o /he end u er2 which mean /ha/ bo/h /he OS# a33lica/ionlayer and /he u er in/erac/ direc/ly wi/h /he of/ware a33lica/ion. Thi layer in/erac/ wi/h of/warea33lica/ion /ha/ im3lemen/ a communica/ing com3onen/. Sucha33lica/ion 3rogram fall ou/ ide /he co3e of /he OS# model. '33lica/ion layer func/ion /y3ically includeiden/ifying communica/ion 3ar/ner 2 de/ermining re ource a0ailabili/y2 and ynchroni:ing communica/ion.hen iden/ifying communica/ion 3ar/ner 2 /he a33lica/ion layer de/ermine /he iden/i/y and a0ailabili/y ofcommunica/ion 3ar/ner for an a33lica/ion wi/h da/a /o /ran mi/. hen de/ermining re ource a0ailabili/y2/he a33lica/ion layer mu / decide whe/her ufficien/ ne/wor1 re ource for /he re@ue /ed communica/ione7i /. #n ynchroni:ing communica/ion2 all communica/ion be/ween a33lica/ion re@uire coo3era/ion /ha/i managed by /he a33lica/ion layer. Some e7am3le of a33lica/ion layer im3lemen/a/ion include Telne/2,ile Tran fer Pro/ocol (,TP)2 and Sim3le %ail Tran fer Pro/ocol (S%TP).1-12

Information *ormatsThe da/a and con/rol informa/ion /ha/ i /ran mi//ed /hrough in/erne/wor1 /a1e a 0arie/y of form . The

/erm u ed /o refer /o /he e informa/ion forma/ are no/ u ed con i /en/ly in /he in/erne/wor1ing indu /ry bu/ ome/ime are u ed in/erchangeably. Common informa/ion forma/ include frame 2 3ac1e/ 2da/agram 2 egmen/ 2 me age 2 cell 2 and da/a uni/ .' frame i an informa/ion uni/ who e ource and de /ina/ion are da/a lin1 layer en/i/ie . ' frame icom3o ed of /he da/a lin1 layer header (and 3o ibly a /railer) and u33er5layer da/a. The header and /railercon/ain con/rol informa/ion in/ended for /he da/a lin1 layer en/i/y in /he de /ina/ion y /em. a/a fromu33er5layer en/i/ie i enca3 ula/ed in /he da/a lin1 layer header and /railer. ,igure 45G illu /ra/e /he ba iccom3onen/ of a da/a lin1 layer frame.


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' packet i an informa/ion uni/ who e ource and de /ina/ion are ne/wor1 layer en/i/ie . ' 3ac1e/ icom3o ed of /he ne/wor1 layer header (and 3o ibly a /railer) and u33er5layer da/a. The header and /railercon/ain con/rol informa/ion in/ended for /he ne/wor1 layer en/i/y in /he de /ina/ion y /em. a/a fromu33er5layer en/i/ie i enca3 ula/ed in /he ne/wor1 layer header and /railer. ,igure 454B illu /ra/e /he ba iccom3onen/ of a ne/wor1 layer 3ac1e/.

The /erm datagram u ually refer /o an informa/ion uni/ who e ource and de /ina/ion are ne/wor1 layeren/i/ie /ha/ u e connec/ionle ne/wor1 er0ice.The /erm segment u ually refer /o an informa/ion uni/ who e ource and de /ina/ion are /ran 3or/ layeren/i/ie .' message i an informa/ion uni/ who e ource and de /ina/ion en/i/ie e7i / abo0e /he ne/wor1 layer(of/en a/ /he a33lica/ion layer).' cell i an informa/ion uni/ of a fi7ed i:e who e ource and de /ina/ion are da/a lin1 layer en/i/ie . Cellare u ed in wi/ched en0ironmen/ 2 uch a ' ynchronou Tran fer %ode ('T%) and Swi/ched%ul/imegabi/ a/a Ser0ice (S% S) ne/wor1 . ' cell i com3o ed -1+of /he header and 3ayload. The header con/ain con/rol informa/ion in/ended for /he de /ina/ion da/a lin1layer en/i/y and i /y3ically = by/e long. The 3ayload con/ain u33er5layer da/a /ha/ i enca3 ula/ed in /hecell header and i /y3ically ?A by/e long. The leng/h of /he header and /he 3ayload field alway are /heame for each cell.


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Data unit i a generic /erm /ha/ refer /o a 0arie/y of informa/ion uni/ . Some common da/a uni/ areer0ice da/a uni/ (S + )2 3ro/ocol da/a uni/ 2 and bridge 3ro/ocol da/a uni/ ( P + ). S + areinforma/ion uni/ from u33er5layer 3ro/ocol /ha/ define a er0ice re@ue / /o a lower5layer 3ro/ocol. P +

i OS# /erminology for a 3ac1e/. P + are u ed by /he 3anning5/ree algori/hm a hello me age .

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M)C )ddressesMedia Access Control (MAC) addre e con i / of a ub e/ of da/a lin1 layer addre e . %'Caddre e iden/ify ne/wor1 en/i/ie in L'N /ha/ im3lemen/ /he #EEE %'C addre e of /he da/a lin1layer. ' wi/h mo / da/a5lin1 addre e 2 %'C addre e are uni@ue for each L'N in/erface. ,igure 454?


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illu /ra/e /he rela/ion hi3 be/ween %'C addre e 2 da/a5lin1 addre e 2 and /he #EEE ub layer of /heda/a lin1 layer.

1-1

%'C addre e are ?A bi/ in leng/h and are e73re ed a 4> he7adecimal digi/ . The fir / < he7adecimaldigi/ 2 which are admini /ered by /he #EEE2 iden/ify /he manufac/urer or 0endor and /hu com3ri e /heOrgani:a/ionally +ni@ue #den/ifier (O+#). The la / < he7adecimal digi/ com3ri e /he in/erface erialnumber2 or ano/her 0alue admini /ered by /he 3ecific 0endor. %'C addre e ome/ime are calledurned-in addresses (!"As) becau e /hey are burned in/o read5only memory (!O%) and are co3iedin/o random5acce memory (!'%) when /he in/erface card ini/iali:e . ,igure 454= illu /ra/e /he %'Caddre forma/.

'etwor% Layer )ddresses' network layer address iden/ifie an en/i/y a/ /he ne/wor1 layer of /he OS# layer . Ne/wor1addre e u ually e7i / wi/hin a hierarchical addre 3ace and ome/ime are called virtual or logicaladdresses . The rela/ion hi3 be/ween a ne/wor1 addre and a de0ice i logical and unfi7edD i/ /y3icallyi ba ed ei/her on 3hy ical ne/wor1 charac/eri /ic (/he de0ice i on a 3ar/icular ne/wor1 egmen/) or ongrou3ing /ha/ ha0e no 3hy ical ba i (/he de0ice i 3ar/ of an '33leTal1 :one). End y /em re@uire onene/wor1 layer addre for each ne/wor1 layer 3ro/ocol /ha/ /hey u33or/. (Thi a ume /ha/ /he de0ice haonly one 3hy ical ne/wor1 connec/ion.) !ou/er and o/her in/erne/wor1ing de0ice re@uire one ne/wor1layer addre 3er 3hy ical ne/wor1 connec/ion for each ne/wor1 layer 3ro/ocol u33or/ed. ,or e7am3le2 a


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rou/er wi/h /hree in/erface each running '33leTal12 TCPH#P2 and OS# mu / ha0e /hree ne/wor1 layeraddre e for each in/erface. The rou/er /herefore ha nine ne/wor1 layer addre e . ,igure454< illu /ra/e how each ne/wor1 in/erface mu / be a igned a ne/wor1 addre for each 3ro/ocolu33or/ed.1-1

Lan .Local )rea 'etwor%/' LAN i a high5 3eed da/a ne/wor1 /ha/ co0er a rela/i0ely mall geogra3hic area. #/ /y3ically connec/wor1 /a/ion 2 3er onal com3u/er 2 3rin/er 2 er0er 2 and o/her de0ice . L'N offer com3u/er u er manyad0an/age 2 including hared acce /o de0ice and a33lica/ion 2 file e7change be/ween connec/ed u er 2and communica/ion be/ween u er 0ia elec/ronic mail and o/her a33lica/ion .

.


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L)' (opolo0iesL'N /o3ologie define /he manner in which ne/wor1 de0ice are organi:ed. ,our common L'N

/o3ologie e7i /9 bu 2 ring2 /ar2 and /ree. The e /o3ologie are logical archi/ec/ure 2 bu/ /he ac/ualde0ice need no/ be 3hy ically organi:ed in /he e configura/ion . Logical bu and ring /o3ologie 2 fore7am3le2 are commonly organi:ed 3hy ically a a /ar. ' us topology i a linear L'N archi/ec/ure inwhich /ran mi ion from ne/wor1 /a/ion 3ro3aga/e /he leng/h of /he medium and are recei0ed by allo/her /a/ion . Of /he /hree mo / widely u ed L'N im3lemen/a/ion 2 E/herne/H#EEE AB>.8 ne/wor1 I including 4BB a eTIim3lemen/ a bu /o3ology2 which i illu /ra/ed in ,igure >58.

2-5' ring topology i a L'N archi/ec/ure /ha/ con i / of a erie of de0ice connec/ed /o one ano/her byunidirec/ional /ran mi ion lin1 /o form a ingle clo ed loo3. o/h To1en !ingH#EEE AB>.= and , #ne/wor1 im3lemen/ a ring /o3ology. ,igure >5? de3ic/ a logical ring /o3ology.

' star topology i a L'N archi/ec/ure in which /he end3oin/ on a ne/wor1 are connec/ed /o a commoncen/ral hub2 or wi/ch2 by dedica/ed lin1 . Logical bu and ring /o3ologie are of/en im3lemen/ed

3hy ically in a /ar /o3ology2 which i illu /ra/ed in ,igure >5=.


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' tree topology i a L'N archi/ec/ure /ha/ i iden/ical /o /he bu /o3ology2 e7ce3/ /ha/ branche wi/hmul/i3le node are 3o ible in /hi ca e. ,igure >5= illu /ra/e a logical /ree /o3ology.2-

L)' $e!icese0ice commonly u ed in L'N include re3ea/er 2 hub 2 L'N e7/ender 2 bridge 2 L'N wi/che 2 androu/er . ' repeater i a 3hy ical layer de0ice u ed /o in/erconnec/ /he media egmen/ of an e7/ended ne/wor1.' re3ea/er e en/ially enable a erie of cable egmen/ /o be /rea/ed a a ingle cable. !e3ea/er recei0eignal from one ne/wor1 egmen/ and am3lify2 re/ime2 and re/ran mi/ /ho e ignal /o ano/her ne/wor1egmen/. The e ac/ion 3re0en/ ignal de/eriora/ion cau ed by long cable leng/h and large number ofconnec/ed de0ice . !e3ea/er are inca3able of 3erforming com3le7 fil/ering and o/her /raffic 3roce ing.#n addi/ion2 all elec/rical ignal 2 including elec/rical di /urbance and o/her error 2 are re3ea/ed andam3lified. The /o/al number of re3ea/er and ne/wor1 egmen/ /ha/ can be connec/ed i limi/ed due /o/iming and o/her i ue . ,igure >5< illu /ra/e a re3ea/er connec/ing /wo ne/wor1 egmen/ .


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' #u i a 3hy ical layer de0ice /ha/ connec/ mul/i3le u er /a/ion 2 each 0ia a dedica/ed cable.Elec/rical in/erconnec/ion are e /abli hed in ide /he hub. ub are u ed /o crea/e a 3hy ical /arne/wor1while main/aining /he logical bu or ring configura/ion of /he L'N. #n ome re 3ec/ 2 a hubfunc/ion a a mul/i3or/ re3ea/er.

' LAN e$tender i a remo/e5acce mul/ilayer wi/ch /ha/ connec/ /o a ho / rou/er. L'N e7/enderforward /raffic from all /he /andard ne/wor1 layer 3ro/ocol ( uch a #P2 #PJ2 and '33leTal1) and fil/er/raffic ba ed on /he %'C addre or ne/wor1 layer 3ro/ocol /y3e. L'N e7/ender cale well becau e /heho / rou/er fil/er ou/ unwan/ed broadca / and mul/ica / . owe0er2 L'N e7/ender are no/ ca3able ofegmen/ing /raffic or crea/ing ecuri/y firewall . ,igure >K; illu /ra/e mul/i3le L'N e7/ender connec/ed/o /he ho / rou/er /hrough a 'N.


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WAN (WIDE AREA NETWORK)

' WAN i a da/a communica/ion ne/wor1 /ha/ co0er a rela/i0ely broad geogra3hic area and /ha/ of/enu e /ran mi ion facili/ie 3ro0ided by common carrier 2 uch a /ele3hone com3anie . 'N/echnologie generally func/ion a/ /he lower /hree layer of /he OS# reference model9 /he 3hy ical layer2/he da/a lin1 layer2 and /he ne/wor1 layer. ,igure 854 illu /ra/e /he rela/ion hi3 be/ween /he common'N /echnologie and /he OS# model.

+-2

"oint-to-"oint Lin%s' point-to-point link 3ro0ide a ingle2 3re5e /abli hed 'N communica/ion 3a/h from /he cu /omer

3remi e /hrough a carrier ne/wor12 uch a a /ele3hone com3any2 /o a remo/e ne/wor1. Poin/5/o53oin/line are u ually lea ed from a carrier and /hu are of/en called lea ed line . ,or a 3oin/5/o53oin/ line2 /hecarrier alloca/e 3air of wire and facili/yhardware /o your line only. The e circui/ are generally 3riced ba ed on bandwid/h re@uired and di /ance

be/ween /he /wo connec/ed 3oin/ . Poin/5/o53oin/ lin1 aregenerally more e73en i0e /han hared er0ice uch a ,rame !elay. ,igure 85> illu /ra/e a /y3ical 3oin/5/o53oin/ lin1 /hrough a 'N.


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Circuit Switchin0%witc#ed circuits allow da/a connec/ion /ha/ can be ini/ia/ed when needed and /ermina/ed whencommunica/ion i com3le/e. Thi wor1 much li1e a normal /ele3hone line wor1 for 0oicecommunica/ion. #n/egra/ed Ser0ice igi/al Ne/wor1 (#S N) i a good e7am3le of circui/ wi/ching.hen a rou/er ha da/a for a remo/e i/e2 /he wi/ched circui/ i ini/ia/ed wi/h /he circui/ number of /heremo/e ne/wor1. #n /he ca e of #S N circui/ 2 /he de0ice ac/ually 3lace a call /o /he /ele3hone number of/he remo/e #S N circui/. hen /he /wo ne/wor1 areconnec/ed and au/hen/ica/ed2 /hey can /ran fer da/a. hen /he da/a /ran mi ion icom3le/e2 /he call can be /ermina/ed. ,igure 858 illu /ra/e an e7am3le of /hi /y3e of circui/.

"ac%et Switchin0&acket switc#ing i a 'N /echnology in which u er hare common carrier re ource . ecau e /hiallow /he carrier /o ma1e more efficien/ u e of i/ infra /ruc/ure2 /he co / /o /he cu /omer i generally

much be//er /han wi/h 3oin/5/o53oin/ line . #n a 3ac1e/ wi/ching e/u32 ne/wor1 ha0e connec/ion in/o /hecarrier6 ne/wor12 and many cu /omer hare /he carrier6 ne/wor1. The carrier can /hen crea/e 0ir/ualcircui/ be/ween cu /omer 6 i/e by which 3ac1e/ of da/a are deli0ered from one /o /he o/her /hrough /hene/wor1. The ec/ion of /he carrier6 ne/wor1 /ha/ i hared i of/en referred /o a a cloud.

Some e7am3le of 3ac1e/5 wi/ching ne/wor1 include ' ynchronou Tran fer %ode ('T%)2 ,rame!elay2 Swi/ched %ul/imegabi/ a/a Ser0ice (S% S)2 and J.>=. ,igure85? how an e7am3le 3ac1e/5 wi/ched circui/. The 0ir/ual connec/ion be/ween cu /omer i/e are of/enreferred /o a a 0ir/ual circui/.


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)' $e!ices'N u e numerou /y3e of de0ice /ha/ are 3ecific /o 'N en0ironmen/ . 'N wi/che 2 acceer0er 2 modem 2 CS+H S+ 2 and #S N /erminal ada3/er are di cu ed in /he following ec/ion . O/herde0ice found in 'N en0ironmen/ /ha/ are u ed in 'N im3lemen/a/ion include rou/er 2 'T%2 wi/che 2 and mul/i3le7er .

)' Switch' WAN switc# i a mul/i3or/ in/erne/wor1ing de0ice u ed in carrier ne/wor1 . The e de0ice /y3ically

wi/ch uch /raffic a ,rame !elay2 J.>=2 and S% S2 and o3era/e a/ /he da/a lin1 layer of /he OS#reference model. ,igure 85= illu /ra/e /wo rou/er a/ remo/e end of a 'N /ha/ are connec/ed by 'Nwi/che .+-


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)ccess Ser!er

'n access server ac/ a a concen/ra/ion 3oin/ for dial5in and dial5ou/ connec/ion . ,igure 8K


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thernet (echnolo0iesThe /erm 't#ernet refer /o /he family of local5area ne/wor1 (L'N) 3roduc/ co0ered by /he #EEE AB>.8/andard /ha/ define wha/ i commonly 1nown a /he CS%'HC 3ro/ocol. Three da/a ra/e are curren/lydefined for o3era/ion o0er o3/ical fiber and /wi /ed53air cable 93 4B %b3 I4B a e5T E/herne/3 4BB %b3 I,a / E/herne/3 4BBB %b3 I$igabi/ E/herne/4B5$igabi/ E/herne/ i under de0elo3men/ and will li1ely be 3ubli hed a /he #EEE AB>.8ae u33lemen/ /o/he #EEE AB>.8 ba e /andard in la/e >BB4 or early >BB>.O/her /echnologie and 3ro/ocol ha0e been /ou/ed a li1ely re3lacemen/ 2 bu/ /he mar1e/ ha 3o1en.E/herne/ ha ur0i0ed a /he major L'N /echnology (i/ i curren/ly u ed for a33ro7ima/ely A= 3ercen/ of/he world6 L'N5connec/ed PC and wor1 /a/ion ) becau e i/ 3ro/ocol ha /he followingcharac/eri /ic 93 # ea y /o under /and2 im3lemen/2 manage2 and main/ain3 'llow low5co / ne/wor1 im3lemen/a/ion3 Pro0ide e7/en i0e /o3ological fle7ibili/y for ne/wor1 in /alla/ion3 $uaran/ee ucce ful in/erconnec/ion and o3era/ion of /andard 5com3lian/ 3roduc/ 2 regardle of manufac/urer 4-2

. thernet 'etwor% lementsE/herne/ L'N con i / of ne/wor1 node and in/erconnec/ing media. The ne/wor1 node fall in/o /wo

major cla e 93 $ata terminal e uipment .$( / I e0ice /ha/ are ei/her /he ource or /he de /ina/ion ofda/aframe . TE are /y3ically de0ice uch a PC 2 wor1 /a/ion 2 file er0er 2 or 3rin/ er0er /ha/2 aa grou32 are all of/en referred /o a end /a/ion .3 $ata communication e uipment .$C / I#n/ermedia/e ne/wor1 de0ice /ha/ recei0e andforwardframe acro /he ne/wor1. CE may be ei/her /andalone de0ice uch a re3ea/er 2 ne/wor1 wi/che 2 and rou/er 2 or communica/ion in/erface uni/ uch a in/erface card and modem .Throughou/ /hi cha3/er2 /andalone in/ermedia/e ne/wor1 de0ice will be referred /o a ei/her intermediate nodes or DC's . Ne/wor1 in/erface card will be referred /o a N"Cs .

The curren/ E/herne/ media o3/ion include /wo general /y3e of co33er cable9 un hielded /wi /ed53air (+TP) and hielded /wi /ed53air (STP)2 3lu e0eral /y3e of o3/ical fiber cable.

thernet 'etwor% (opolo0ies andStructuresL'N /a1e on many /o3ological configura/ion 2 bu/ regardle of /heir i:e or com3le7i/y2 all will be acombina/ion of only /hree ba ic in/erconnec/ion /ruc/ure or ne/wor1 building bloc1 .The im3le / /ruc/ure i /he 3oin/5/o53oin/ in/erconnec/ion2 hown in ,igure ;54. Only /wo ne/wor1 uni/are in0ol0ed2 and /he connec/ion may be TE5/o5 TE2 TE5/o5 CE2 or CE5/o5 CE. The cable in


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3oin/5/o53oin/ in/erconnec/ion i 1nown a a ne/wor1 lin1. The ma7imum allowable leng/h of /he lin1de3end on /he /y3e of cable and /he /ran mi ion me/hod /ha/ i u ed.4-+

The original E/herne/ ne/wor1 were im3lemen/ed wi/h a coa7ial bu /ruc/ure2 a hown in ,igure ;5>.Segmen/ leng/h were limi/ed /o =BB me/er 2 and u3 /o 4BB /a/ion could be connec/ed /o a ingleegmen/. #ndi0idual egmen/ could be in/erconnec/ed wi/h re3ea/er 2 a long a mul/i3le 3a/h did no/e7i / be/ween any /wo /a/ion on /he ne/wor1 and /he number of TE did no/ e7ceed 4B>?. The /o/al

3a/h di /ance be/ween /he mo /5di /an/ 3air of /a/ion wa al o no/ allowed /o e7ceed a ma7imum 3re cribed 0alue.

(he thernet M)C Su6layer

The %'C ublayer ha /wo 3rimary re 3on ibili/ie 93 a/a enca3 ula/ion2 including frame a embly before /ran mi ion2 and frame 3ar ingHerror de/ec/ion during and af/er rece3/ion3 %edia acce con/rol2 including ini/ia/ion of frame /ran mi ion and reco0ery from /ran mi ion

failure

(he Basic thernet *rame *ormat

The #EEE AB>.8 /andard define a ba ic da/a frame forma/ /ha/ i re@uired for all %'C im3lemen/a/ion 2 3lu e0eral addi/ional o3/ional forma/ /ha/ are u ed /o e7/end /he 3ro/ocol6 ba ic ca3abili/y. The ba icda/a frame forma/ con/ain /he e0en field hown in ,igure ;5


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recei0ing /a/ion /ha/ a frame i coming2 and /ha/ 3ro0ide a mean /o ynchroni:e /heframe5rece3/ion 3or/ion of recei0ing 3hy ical layer wi/h /he incoming bi/ /ream.3 Start-of-frame delimiter .SO*/ ICon i / of 4 by/e. The SO, i an al/erna/ing 3a//ern ofone and:ero 2 ending wi/h /wo con ecu/i0e 45bi/ indica/ing /ha/ /he ne7/ bi/ i /he lef/5mo / bi/ in /helef/5mo / by/e of /he de /ina/ion addre .3 $estination address .$)/ ICon i / of < by/e . The ' field iden/ifie which /a/ion( )houldrecei0e /he frame. The lef/5mo / bi/ in /he ' field indica/e whe/her /he addre i an indi0idualaddre (indica/ed by a B) or a grou3 addre (indica/ed by a 4). The econd bi/ from /he lef/ indica/ewhe/her /he ' i globally admini /ered (indica/ed by a B) or locally admini /ered (indica/ed by a4). The remaining ?< bi/ are a uni@uely a igned 0alue /ha/ iden/ifie a ingle /a/ion2 a definedgrou3 of /a/ion 2 or all /a/ion on /he ne/wor1.3 Source addresses .S)/ ICon i / of < by/e . The S' field iden/ifie /he ending /a/ion. TheS' ialway an indi0idual addre and /he lef/5mo / bi/ in /he S' field i alway B.3 Len0th7(ype ICon i / of > by/e . Thi field indica/e ei/her /he number of %'C5clien/ da/a by/e/ha/ are con/ained in /he da/a field of /he frame2 or /he frame /y3e # if /he frame i a embled u ingan o3/ional forma/. #f /he Leng/hHTy3e field 0alue i le /han or e@ual /o 4=BB2 /he number of LLC

by/e in /he a/a field i e@ual /o /he Leng/hHTy3e field 0alue. #f /he Leng/hHTy3e field 0alue igrea/er /han 4=8


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da/a informa/ion from /he LLC ublayer2 /he %'C begin /he /ran mi ion e@uence by /ran ferring /heLLC informa/ion in/o /he %'C frame buffer.3 The 3reamble and /ar/5of5frame delimi/er are in er/ed in /he P!E and SO, field .3 The de /ina/ion and ource addre e are in er/ed in/o /he addre field .3 The LLC da/a by/e are coun/ed2 and /he number of by/e i in er/ed in/o /he Leng/hHTy3e field.3 The LLC da/a by/e are in er/ed in/o /he a/a field. #f /he number of LLC da/a by/e i le /han ?


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'l/hough 4B a e5T may be con idered e en/ially ob ole/e in ome circle 2 i/ i included here becau e/here are /ill many 4B a e5T E/herne/ ne/wor1 2 and becau e full5du3le7 o3era/ion ha gi0en 4B a eT ane7/ended life. 4B a e5T wa al o /he fir / E/herne/ 0er ion /o include a lin1 in/egri/y /e / /o de/ermine /heheal/h of /he lin1. #mmedia/ely af/er 3oweru32 /he P%' /ran mi/ a normal lin1 3ul e (NLP) /o /ell /he

N#C a/ /he o/her end of /he lin1 /ha/ /hi N#C wan/ /o e /abli h an ac/i0e lin1 connec/ion93 #f /he N#C a/ /he o/her end of /he lin1 i al o 3owered u32 i/ re 3ond wi/h i/ own NLP.3 #f /he N#C a/ /he o/her end of /he lin1 i no/ 3owered u32 /hi N#C con/inue ending an NLP abou/once e0ery 4< m un/il i/ recei0e a re 3on e.The lin1 i ac/i0a/ed only af/er bo/h N#C are ca3able of e7changing 0alid NLP .

1&& M6ps8*ast thernet#ncrea ing /he E/herne/ /ran mi ion ra/e by a fac/or of /en o0er 4B a e5T wa no/ a im3le /a 12 and /he

effor/ re ul/ed in /he de0elo3men/ of /hree e3ara/e 3hy ical layer /andard for 4BB %b3 o0er +TPcable9 4BB a e5TJ and 4BB a e5T? in 4GG=2 and 4BB a e5T> in 4GG;. Each wa defined wi/h differen/encoding re@uiremen/ and a differen/ e/ of media5de3enden/ ublayer 2 e0en /hough /here i omeo0erla3 in /he lin1 cabling. Table ;5> com3are /he 3hy ical layer charac/eri /ic of 4B a e5T /o /he0ariou 4BB a e 0er ion .


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'l/hough no/ all /hree 4BB5%b3 0er ion were ucce ful in /he mar1e/3lace2 all /hree ha0e beendi cu ed in /he li/era/ure2 and all /hree did im3ac/ fu/ure de ign . ' uch2 all /hree are im3or/an/ /ocon ider here.1&&Base-94BB a e5J wa de igned /o u33or/ /ran mi ion o0er ei/her /wo 3air of Ca/egory = +TP co33er wireor /wo /rand of o3/ical fiber. 'l/hough /he encoding2 decoding2 and cloc1 reco0ery 3rocedure are /heame for bo/h media2 /he ignal /ran mi ion i differen/Ielec/rical 3ul e in co33er and ligh/ 3ul e ino3/ical fiber. The ignal /ran cei0er /ha/ were included a 3ar/ of /he P%' func/ion in /he generic logicalmodel of ,igure ;54? were redefined a /he e3ara/e 3hy ical media5de3enden/ (P% ) ub layer hownin ,igure ;54


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dedica/ed /o /ran mi ion in one direc/ion only. ,rame /ran mi ion u e bo/h half5du3le7 3air 2 3lu /heim3le7 3air /ha/ i a33ro3ria/e for /he /ran mi ion direc/ion2 a hown in ,igure ;54A. The im3le7 3airfor /he o33o i/e direc/ion 3ro0ide carrier en e and colli ion de/ec/ion. ,ull5du3le7 o3era/ion canno/ beu33or/ed on 4BB a e5T? .

4BB a e5T? u e an A dual5du3le7 ba eband /ran mi ion me/hod end encodedymbol imul/aneou ly in bo/h direc/ion on bo/h wire 3air 2 a hown in ,igure ;5>B. The /ermMT J 89>Q indica/e /he > mo / ignifican/ bi/ in /he nibble before encoding and /ran mi ion.M! J 89>Q indica/e /he ame > bi/ af/er recei3/ and decoding.


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1&&&Base-(4BBB a e5T E/herne/ 3ro0ide full5du3le7 /ran mi ion o0er four53air Ca/egory = or be//er +TP cable.4BBB a e5T i ba ed largely on /he finding and de ign a33roache /ha/ led /o /he de0elo3men/ of /he,a / E/herne/ 3hy ical layer im3lemen/a/ion 93 4BB a e5TJ 3ro0ed /ha/ binary ymbol /ream could be ucce fully /ran mi//ed o0er Ca/egory =+TP cable a/ 4>= % d.3 4BB a e5T? 3ro0ided a ba ic under /anding of /he 3roblem rela/ed /o ending mul/ile0el ignalo0er four wire 3air .3 4BB a e5T> 3ro0ed /ha/ P'%= encoding2 cou3led wi/h digi/al ignal 3roce ing2 could handle bo/himul/aneou /wo5way da/a /ream and 3o/en/ial cro /al1 3roblem re ul/ing from alien ignal on

adjacen/ wire 3air . 4BBB a e5T cramble each by/e in /he %'C frame /o randomi:e /he bi/ e@uence before i/ i encoded u ing a ?5 2 A5S/a/e Trelli ,orward Error Correc/ion (,EC) coding in which fourP'%= ymbol are en/ a/ /he ame /ime o0er four wire 3air . ,our of /he fi0e le0el in each P'%=ymbol re3re en/ > bi/ in /he da/a by/e. The fif/h le0el i u ed for ,EC coding2 which enhance ymbolreco0ery in /he 3re ence of noi e and cro /al1. Se3ara/e crambler for /he ma /er and la0e P - crea/ee en/ially uncorrela/ed da/a /ream be/ween /he /wo o33o i/e5 /ra0elling ymbol /ream on each wire

3air. The4BBB a e5T lin1 /o3ology i hown in ,igure ;5>8. The /erm MT J ;9 mo /ignifican/ bi/ in /he da/a by/e before encoding and /ran mi ion. M! J ;9 bi/af/er recei3/ and decoding.The cloc1 reco0ery and ma /erH la0e loo3 /iming 3rocedure are e en/ially /he ame a /ho e u ed in4BB a e5T> ( ee ,igure ;5>?). hich N#C will be ma /er (/y3ically /he N#C in a mul/i3or/ in/ermedia/e

ne/wor1 node) and which will be la0e i de/ermined during au/onego/ia/ion.


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Each /ran mi//ed frame i enca3 ula/ed wi/h /ar/5of5 /ream and end5of5 /ream delimi/er 2 and loo3/iming i main/ained by con/inuou /ream of # LE ymbol en/ on each wire 3air during in/erframega3 . 4BBB a e5T u33or/ bo/h half5du3le7 and full5du3le7 o3era/ion.

1&&&Base-9'll /hree 4BBB a e5J 0er ion u33or/ full5du3le7 binary /ran mi ion a/ 4>=B %b3 o0er /wo /randof o3/ical fiber or /wo STP co33er wireK3air 2 a hown in ,igure ;5>=. Tran mi ion coding i ba edon /he 'NS# ,ibre Channel A H4B encoding cheme. Each A5bi/ da/a by/e i ma33ed in/o a 4B5bi/code5grou3 for bi/5 erial /ran mi ion. Li1e earlier E/herne/ 0er ion 2 each da/a frame i enca3 ula/eda/ /he 3hy ical layer before /ran mi ion2 and lin1 ynchroni:a/ion i main/ained by ending a con/inuou/ream of # LE code5grou3 during in/erframe ga3 . 'll 4BBB a e5J 3hy ical layer u33or/ bo/h half5du3le7 and full5du3le7 o3era/ion.


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The 3rinci3al difference among /he 4BBB a e5J 0er ion are /he lin1 media and connec/or /ha/ /he 3ar/icular 0er ion will u33or/ and2 in /he ca e of o3/ical media2 /he wa0eleng/h of /he o3/ical ignal( ee Table ;58).

'etwor% Ca6lin08Lin% Crosso!er Re uirementsLin1 com3a/ibili/y re@uire /ha/ /he /ran mi//er a/ each end of /he lin1 be connec/ed /o /he recei0er a//he o/her end of /he lin1. owe0er2 becau e cable connec/or a/ bo/h end of /he lin1 are 1eyed /he ame2/he conduc/or mu / cro o0er a/ ome 3oin/ /o en ure /ha/ /ran mi//er ou/3u/ are alway connec/ed /orecei0er in3u/ .

+nfor/una/ely2 when /hi re@uiremen/ fir / came u3 in /he de0elo3men/ of 4B a e5T2 #EEE AB>.8 cho eno/ /o ma1e a hard rule a /o whe/her /he cro o0er hould be im3lemen/ed in /he cable a hown in ,igure;5>


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#n /ead2 #EEE AB>.8 defined /wo rule and made /wo recommenda/ion 93 There mu / be an odd number of cro o0er in all mul/iconduc/or lin1 .3 #f a P% i e@ui33ed wi/h an in/ernal cro o0er2 i/ % # mu / be clearly labeled wi/h /he gra3hicalJ ymbol.3 #m3lemen/a/ion of an in/ernal cro o0er func/ion i o3/ional.3 hen a TE i connec/ed /o a re3ea/er or wi/ch ( CE) 3or/2 i/ i recommended /ha/ /he cro o0er

be im3lemen/ed wi/hin /he CE 3or/. The e0en/ual re ul/ wa /ha/ 3or/ in mo / CE were e@ui33edwi/h P% /ha/ con/ained in/ernal cro o0er circui/ry and /ha/ TE had P% wi/hou/ in/ernalcro o0er . Thi led /o /he following of/5@uo/ed de fac/o in /alla/ion rule 93 + e a /raigh/5/hrough cable when connec/ing TE /o CE. + e a cro o0er cable when connec/ingTE /o TE or CE /o CE. +nfor/una/ely2 /he de fac/o rule doe no/ a33ly /o all E/herne/ 0er ion /ha/ha0e been de0elo3ed ub e@uen/ /o 4B a e5T. ' /hing now /and2 /he following i /rue93 'll fiber5ba ed y /em u e cable /ha/ ha0e /he cro o0er im3lemen/ed wi/hin /he cable.3 'll 4BB a e y /em u ing /wi /ed53air lin1 u e /he ame rule and recommenda/ion a 4B a e5T.3 4BBB a e5T N#C may im3lemen/ a elec/able in/ernal cro o0er o3/ion /ha/ can be nego/ia/ed andenabled during au/onego/ia/ion. hen /he elec/able cro o0er o3/ion i no/ im3lemen/ed2 4B a e5Trule and recommenda/ion a33ly.

Multispeed 'ICs'u/o5nego/ia/ion o3ened /he door /o /he de0elo3men/ of low5co /2 mul/i 3eed N#C /ha/2 for e7am3le2u33or/ bo/h half5 and full5du3le7 o3era/ion under ei/her 4BB a e5TJ or 4B a e5T ignaling

3rocedure . %ul/i 3eed N#C allow /aged ne/wor1 u3grade in which /he 4B a e5T half5du3le7 end/a/ion can be connec/ed /o 4BB a e5TJ full5du3le7 wi/ch 3or/ wi/hou/ re@uiring /he N#C in /he PC/o be changed. Then2 a more bandwid/h i needed for indi0idual PC 2 /he N#C in /ho e PC can beu3graded /o 4BB a e5TJ full5du3le7 mode.4-+2


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Internet ProtocolsInternet Protocol (IP)The #n/erne/ Pro/ocol (#P) i a ne/wor15layer (Layer 8) 3ro/ocol /ha/ con/ain addre ing informa/ion andome con/rol informa/ion /ha/ enable 3ac1e/ /o be rou/ed. #P i documen/ed in !,C ;G4 and i /he

3rimary ne/wor15layer 3ro/ocol in /he #n/erne/ 3ro/ocol ui/e. 'long wi/h /he Tran mi ion Con/rolPro/ocol (TCP)2 #P re3re en/ /he hear/ of /he #n/erne/ 3ro/ocol . #P ha /wo 3rimary re 3on ibili/ie 9

3ro0iding connec/ionle 2 be /5effor/ deli0ery of da/agram /hrough anin/erne/wor1D and 3ro0iding fragmen/a/ion and rea embly of da/agram /o u33or/ da/a lin1 wi/hdifferen/ ma7imum5/ran mi ion uni/ (%T+) i:e .


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IP Packet For at

The following di cu ion de cribe /he #P 3ac1e/ field illu /ra/ed in ,igure 8B5>9RVersion #ndica/e /he 0er ion of #P curren/ly u ed.R IP Header Length ( # L)I#ndica/e /he da/agram header leng/h in 8>5bi/ word .RType-of-Service IS3ecifie how an u33er5layer 3ro/ocol would li1e a curren/ da/agram /o behandled2 and a ign da/agram 0ariou le0el of im3or/ance.

RTotal Length IS3ecifie /he leng/h2 in by/e 2 of /he en/ire #P 3ac1e/2 including /he da/a andheader.R Identification ICon/ain an in/eger /ha/ iden/ifie /he curren/ da/agram. Thi field i u ed /o hel3

3iece /oge/her da/agram fragmen/ .R Flags ICon i / of a 85bi/ field of which /he /wo low5order (lea /5 ignifican/) bi/ con/rolfragmen/a/ion. The low5order bi/ 3ecifie whe/her /he 3ac1e/ can be fragmen/ed. The middle bi/3ecifie whe/her /he 3ac1e/ i /he la / fragmen/ in a erie of fragmen/ed 3ac1e/ . The /hird or high5order bi/ i no/ u ed.R Fragment Offset I#ndica/e /he 3o i/ion of /he fragmen/6 da/a rela/i0e /o /he beginning of /heda/a in /he original da/agram2 which allow /he de /ina/ion #P 3roce /o 3ro3erly recon /ruc/ /he


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original da/agram.R Time5/o5Li0eI%ain/ain a coun/er /ha/ gradually decremen/ down /o :ero2 a/ which 3oin/ /heda/agram i di carded. Thi 1ee3 3ac1e/ from loo3ing endle ly.R Pro/ocolI#ndica/e which u33er5layer 3ro/ocol recei0e incoming 3ac1e/ af/er #P 3roce ing icom3le/e.R eader Chec1 umI el3 en ure #P header in/egri/y.R Source 'ddre IS3ecifie /he ending node.R e /ina/ion 'ddre IS3ecifie /he recei0ing node.R O3/ion I'llow #P /o u33or/ 0ariou o3/ion 2 uch a ecuri/y.R a/aICon/ain u33er5layer informa/ion.

IP A!!ress"n#' wi/h any o/her ne/wor15layer 3ro/ocol2 /he #P addre ing cheme i in/egral /o /he 3roce of rou/ing #P da/agram /hrough an in/erne/wor1. Each #P addre ha 3ecific com3onen/ and follow a

ba ic forma/. The e #P addre e can be ubdi0ided and u ed /o crea/e addre e for ubne/wor1 2

Each ho / on a TCPH#P ne/wor1 i a igned a uni@ue 8>5bi/ logical addre /ha/ i di0ided in/o /womain 3ar/ 9 /he ne/wor1 number and /he ho / number. The ne/wor1 number iden/ifie a ne/wor1 and mu / be a igned by /he #n/erne/ Ne/wor1 #nforma/ion Cen/er (#n/erN#C) if /he ne/wor1 i /o be 3ar/ of /he#n/erne/. 'n #n/erne/ Ser0ice Pro0ider (#SP) can ob/ain bloc1 of ne/wor1 addre e from /he#n/erN#C and can i/ elf a ign addre 3ace a nece ary. The ho / number iden/ifie a ho / on ane/wor1 and i a igned by /he local ne/wor1 admini /ra/or.

IP A!!ress For atThe 8>5bi/ #P addre i grou3ed eigh/ bi/ a/ a /ime2 e3ara/ed by do/ 2 and re3re en/ed in decimalforma/ (1nown a dotted decimal notation ). Each bi/ in /he oc/e/ ha a binary weigh/ (4>A2


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IP A!!ress Classes#P addre ing u33or/ fi0e differen/ addre cla e 9 '2 2C2 2 and E. Only cla e '2 2 and C area0ailable for commercial u e. The lef/5mo / (high5order) bi/ indica/e /he ne/wor1 cla . Table 8B54

3ro0ide reference informa/ion abou/ /he fi0e #P addre cla e .

The cla of addre can be de/ermined ea ily by e7amining /he fir / oc/e/ of /he addre andma33ing /ha/ 0alue /o a cla range in /he following /able. #n an #P addre of 4;>.84.4.>2 for e7am3le2 /he fir / oc/e/ i 4;>. ecau e 4;> fall be/ween 4>A and 4G42 4;>.84.4.> i a Cla addre . ,igure 8B5= ummari:e /he range of 3o ible 0alue for /he fir / oc/e/ of each addre cla .


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IP S$%net A!!ress"n##P ne/wor1 can be di0ided in/o maller ne/wor1 called ubne/wor1 (or ubne/ ). Subne//ing

3ro0ide /he ne/wor1 admini /ra/or wi/h e0eral benefi/ 2 including e7/ra fle7ibili/y2 more efficien/u e of ne/wor1 addre e 2 and /he ca3abili/y /o con/ain broadca / /raffic (a broadca / will no/ croa rou/er).Subne/ are under local admini /ra/ion. ' uch2 /he ou/ ide world ee an organi:a/ion a a inglene/wor1 and ha no de/ailed 1nowledge of /he organi:a/ion6 in/ernal /ruc/ure.' gi0en ne/wor1 addre can be bro1en u3 in/o many ubne/wor1 . ,or e7am3le2 4;>.4.4.B2 4;>.4.4


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Subne/ ma 1 u e /he ame forma/ and re3re en/a/ion /echni@ue a #P addre e . The ubne/ ma 12howe0er2 ha binary 4 in all bi/ 3ecifying /he ne/wor1 and ubne/wor1 field 2 and binary B in all bi/3ecifying /he ho / field. ,igure 8B5; illu /ra/e a am3le ubne/ ma 1.

Subne/ ma 1 bi/ hould come from /he high5order (lef/5mo /) bi/ of /he ho / field2 a ,igure 8B5Aillu /ra/e . e/ail of Cla and C ubne/ ma 1 /y3e follow.

*ariou /y3e of ubne/ ma 1 e7i / for Cla and C ubne/ .The defaul/ ubne/ ma 1 for a Cla addre /ha/ ha no ubne//ing i >==.>==.B.B2 while /he ubne/ma 1 for a Cla addre 4;4.4==.>==.>==.B. The rea onfor /hi i /ha/ eigh/ bi/ of ubne//ing or > A K > (4 for /he ne/wor1 addre and 4 for /he broadca / addre ) >=? ubne/ 3o ible2 wi/h > A K > >=? ho / 3er ubne/.The ubne/ ma 1 for a Cla C addre 4G>.4.B /ha/ 3ecifie fi0e bi/ of ubne//ing i>==.>==.>==.>?A. i/h fi0e bi/ a0ailable for ubne//ing2 > = K > 8B ubne/ 3o ible2 wi/h


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>8 K > < ho / 3er ubne/.The reference char/ hown in /able 8BK> and /able 8BK8 can be u ed when 3lanning Cla and Cne/wor1 /o de/ermine /he re@uired number of ubne/ and ho / 2 and /he a33ro3ria/e ubne/ ma 1.

The rou/er 3erform a e/ 3roce /o de/ermine /he ne/wor1 (or more 3ecifically2 /he ubne/wor1)addre . ,ir /2 /he rou/er e7/rac/ /he #P de /ina/ion addre from /he incoming 3ac1e/ and re/rie0e/he in/ernal ubne/ ma 1. #/ /hen 3erform a logical !" o3era/ion /o ob/ain /he ne/wor1 number.Thi cau e /he ho / 3or/ion of /he #P de /ina/ion addre /o be remo0ed2 while /he de /ina/ion

ne/wor1 number remain . The rou/er /hen loo1 u3 /he de /ina/ion ne/wor1 number and ma/che i/wi/h an ou/going in/erface. ,inally2 i/ forward /he frame /o /he de /ina/ion #P addre . S3ecificregarding /he logical 'N o3era/ion are di cu ed in /he following ec/ion.


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IP Ro$t"n##P rou/ing 3ro/ocol are dynamic. ynamic rou/ing call for rou/e /o be calcula/ed au/oma/ically a/regular in/er0al by of/ware in rou/ing de0ice . Thi con/ra / wi/h /a/ic rou/ing2 where rou/er are

e /abli hed by /he ne/wor1 admini /ra/or and do no/ change un/il /he ne/wor1 admini /ra/or change /hem.'n #P rou/ing /able2 which con i / of de /ina/ion addre Hne7/ ho3 3air 2 i u ed /o enable dynamicrou/ing. 'n en/ry in /hi /able2 for e7am3le2 would be in/er3re/ed a follow 9 /o ge/ /o ne/wor1 4;>.84.B.B2end /he 3ac1e/ ou/ E/herne/ in/erface B (EB).#P rou/ing 3ecifie /ha/ #P da/agram /ra0el /hrough in/erne/wor1 one ho3 a/ a /ime. The en/irerou/e i no/ 1nown a/ /he on e/ of /he journey2 howe0er. #n /ead2 a/ each /o32 /he ne7/ de /ina/ion icalcula/ed by ma/ching /he de /ina/ion addre wi/hin /he da/agram wi/h an en/ry in /he curren/node6 rou/ing /able.Each node6 in0ol0emen/ in /he rou/ing 3roce i limi/ed /o forwarding 3ac1e/ ba ed on in/ernalinforma/ion. The node do no/ moni/or whe/her /he 3ac1e/ ge/ /o /heir final de /ina/ion2 nor doe #P

3ro0ide for error re3or/ing bac1 /o /he ource when rou/ing anomalie occur. Thi /a 1 i lef/ /o

ano/her #n/erne/ 3ro/ocol2 /he #n/erne/ Con/rol5%e age Pro/ocol (#C%P)2 which i di cu ed in /hefollowing ec/ion.

Transmission Control Protocol (TCP)The TCP 3ro0ide reliable /ran mi ion of da/a in an #P en0ironmen/. TCP corre 3ond /o /he/ran 3or/ layer (Layer ?) of /he OS# reference model. 'mong /he er0ice TCP 3ro0ide are /reamda/a /ran fer2 reliabili/y2 efficien/ flow con/rol2 full5du3le7 o3era/ion2 and mul/i3le7ing.i/h /ream da/a /ran fer , TCP deli0er an un /ruc/ured /ream of by/e iden/ified by e@uencenumber . Thi er0ice benefi/ a33lica/ion becau e /hey do no/ ha0e /o cho3 da/a in/o bloc1 before

handing i/ off /o TCP. #n /ead2 TCP grou3 by/e in/o egmen/ and 3a e /hem /o #P for deli0ery.TCP offer reliabili/y by 3ro0iding connec/ion5orien/ed2 end5/o5end reliable 3ac1e/ deli0ery /hrough anin/erne/wor1. #/ doe /hi by e@uencing by/e wi/h a forwarding ac1nowledgmen/ number /ha/ indica/e /o/he de /ina/ion /he ne7/ by/e /he ource e73ec/ /o recei0e. y/e no/ ac1nowledged wi/hin a 3ecified /ime

3eriod are re/ran mi//ed. The reliabili/y mechani m of TCP allow de0ice /o deal wi/h lo /2 delayed2du3lica/e2 or mi read 3ac1e/ . ' /ime5ou/ mechani m allow de0ice /o de/ec/ lo / 3ac1e/ and re@ue /re/ran mi ion. TCP offer efficien/ flow con/rol2 which mean /ha/2 when ending ac1nowledgmen/ bac1/o /he ource2 /he recei0ing TCP 3roce indica/e /he highe / e@uence number i/ can recei0e wi/hou/o0erflowing i/ in/ernal buffer .,ull5du3le7 o3era/ion mean /ha/ TCP 3roce e can bo/h end and recei0e a/ /he ame /ime.,inally2 TCP6 mul/i3le7ing mean /ha/ numerou imul/aneou u33er5layer con0er a/ion can be

mul/i3le7ed o0er a ingle connec/ion.

TCP Packet Format,igure 8B54B illu /ra/e /he field and o0erall forma/ of a TCP 3ac1e/.


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TCP Packet Field DescriptionsThe following de cri3/ion ummari:e /he TCP 3ac1e/ field illu /ra/ed in ,igure 8B54B9RSo#rce Port and "estination Port I#den/ifie 3oin/ a/ which u33er5layer ource and de /ina/ion

3roce e recei0e TCP er0ice .RSe$#ence !#m%er I+ ually 3ecifie /he number a igned /o /he fir / by/e of da/a in /he curren/me age. #n /he connec/ion5e /abli hmen/ 3ha e2 /hi field al o can be u ed /o iden/ify an ini/iale@uence number /o be u ed in an u3coming /ran mi ion.R c&no'ledgment !#m%er ICon/ain /he e@uence number of /he ne7/ by/e of da/a /he ender of /he 3ac1e/ e73ec/ /o recei0e.R "ata Offset I#ndica/e /he number of 8>5bi/ word in /he TCP header.R eserved I!emain re er0ed for fu/ure u e.

R Flags ICarrie a 0arie/y of con/rol informa/ion2 including /he S-N and 'C" bi/ u ed for connec/ion e /abli hmen/2 and /he ,#N bi/ u ed for connec/ion /ermina/ion.R)indo' IS3ecifie /he i:e of /he ender6 recei0e window (/ha/ i 2 /he buffer 3ace a0ailable forincoming da/a).R*hec&s#m I#ndica/e whe/her /he header wa damaged in /ran i/.R+rgent Pointer IPoin/ /o /he fir / urgen/ da/a by/e in /he 3ac1e/.ROptions IS3ecifie 0ariou TCP o3/ion .R "ata ICon/ain u33er5layer informa/ion.


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Internet Protocols Application-Layer ProtocolsThe #n/erne/ 3ro/ocol ui/e include many a33lica/ion5layer 3ro/ocol /ha/ re3re en/ a wide 0arie/yof a33lica/ion 2 including /he following9R File Transfer Protocol (FTP, I%o0e file be/ween de0ice

RSimple !et'or&- anagement Protocol (S! P, IPrimarily re3or/ anomalou ne/wor1 condi/ion and e/ ne/wor1 /hre hold 0alueRTelnet ISer0e a a /erminal emula/ion 3ro/ocolR . )indo's ISer0e a a di /ribu/ed windowing and gra3hic y /em u ed for communica/ion

be/ween J /erminal and +N#J wor1 /a/ionR !et'or& File System (!FS,/ 01ternal "ata epresentation (." ,/ and emote Proced#re *all ( P*, I or1 /oge/her /o enable /ran 3aren/ acce /o remo/e ne/wor1 re ourceRSimple ail Transfer Protocol (S TP, IPro0ide elec/ronic mail er0iceR "omain !ame System ("!S, ITran la/e /he name of ne/wor1 node in/o ne/wor1 addre e

Subnet Mask ' ubne/ ma 1 allow you /o iden/ify which 3ar/ of an #P addre i re er0ed for /he ne/wor12 and which

3ar/ i a0ailable for ho / u e. #f you loo1 a/ /he #P addre alone2 e 3ecially now wi/h cla le in/er5domain rou/ing2 you can / /ell which 3ar/ of /he addre i which. 'dding /he ubne/ ma 12 or ne/ma 12gi0e you all /he informa/ion you need /o calcula/e ne/wor1 and ho / 3or/ion of /he addre wi/h ea e. #nummary2 1nowing /he ubne/ ma 1 can allow you /o ea ily calcula/e whe/her #P addre e are on/he ame ubne/2 or no/.

e/ermining ne/wor1 and ho / 3or/ion of an #P addre u ing a ubne/ ma 1.To de/ermine wha/ /hene/wor1 addre i for any gi0en #P addre 2 you merely ha0e /o con0er/ bo/h oc/al addre e in/o binary2and do a bi/wi e 'N o3era/ion. 'n e7am3le u ing an #P addre of 4===.>==.>==.>?B follow 9#P 'ddre 9 4BB444BB.4BB44B4B.B4B4BBB4.BB444BBBSubne/ ma 19 44444444.44444444.44444444.4444BBBBi/wi e 'N 55555555555555555555555555555555555555555555555

!e ul/9 4BB444BB.4BB44B4B.B4B4BBB4.BB44BBBB' you can ee2 /he ne/wor1 addre for /he #P addre and ubne/ ma 1 in @ue /ion i 4=


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number of bi/ from /he righ/ un/il you ge/ /o /he fir / 4 in /he binary ne/wor1 addre di 3lay. Tha/number will be /he 3ower you rai e > /o for /he calcula/ion of 3o ible number of ho / . -ou mu / al oub/rac/ /wo from /he re ul/ becau e one addre i re er0ed for broadca / and ne/wor1 addre e . Thilea0e you wi/h /he final algori/hm of >Un5>. #n /hi ca e /here are ? bi/ of B in /he ne/wor1 addre 2lea0ing you wi/h >U?5> ho / 3o ible2 or 4? ho / . Thi mean /ha/ your ne/wor1 addre i 4=


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$LSw OperationLSw in0ol0e e0eral o3era/ional /age . Two LSw 3ar/ner e /abli h /wo TCP connec/ion wi/h eacho/her. TCP connec/ion 3ro0ide /he founda/ion for /he LSw communica/ion. ecau e TCP 3ro0ide forreliable and guaran/eed deli0ery of #P /raffic2 i/ en ure /he deli0ery and in/egri/y of /he /raffic /ha/ i

being enca3 ula/ed in /he #P 3ro/ocol2 which2 in /hi ca e2 i SN' and Ne/ #OS /raffic. 'f/er a connec/ioni e /abli hed2 /he LSw 3ar/ner e7change a li / of u33or/ed ca3abili/ie . Thi i

3ar/icularly 0i/al when /he LSw 3ar/ner are manufac/ured by differen/ 0endor . Ne7/2 /he LSw

3ar/ner e /abli h circui/ be/ween SN' or Ne/ #OS end y /em 2 and informa/ion frame can flow o0er/he circui/.$LSw Capa6ilities ;chan0eLSw ca3abili/ie e7change i ba ed on a wi/ch5/o5 wi/ch con/rol me age /ha/ de cribe /heca3abili/ie of /he ending da/a5lin1 wi/ch. ' ca3abili/ie e7change con/rol me age i en/ af/er /hewi/ch5/o5 wi/ch connec/ion i e /abli hed or during run /ime2 if cer/ain o3era/ional 3arame/er /ha/ mu /

be communica/ed /o /he 3ar/ner wi/ch ha0e changed. uring /he ca3abili/ie e7change2 a number ofca3abili/ie are iden/ified and nego/ia/ed. Ca3abili/ie e7changed be/ween LSw 3ar/ner include /hefollowing93 LSw 0er ion number 3 #ni/ial 3acing window i:e (recei0e window i:e)

3 Ne/ #OS u33or/3 Li / of u33or/ed lin1 S'P (LS'P )3 Number of TCP e ion u33or/ed3 %'C addre li /3 Ne/ #OS name li /3 Search frame u33or/


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$LSw Circuit sta6lishmentThe 3roce of circui/ e /abli hmen/ be/ween a 3air of end y /em in LSw in0ol0e loca/ing /he /arge/end y /em and e//ing u3 da/a5lin1 con/rol ( LC) connec/ion be/ween each end y /em and i/ localrou/er. The 3ecific of circui/ e /abli hmen/ differ ba ed on /raffic /y3e.

One of /he 3rimary func/ion of LSw i /o 3ro0ide a /ran 3or/ mechani m for SN' /raffic. SN' circui/e /abli hmen/ in0ol0e e0eral di /inc/ /age and i illu /ra/ed in ,igure >G5


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Ne/ #OS circui/ e /abli hmen/2 LSw node end a name @uery wi/h a Ne/ #OS name (no/ a canureachframe 3ecifying a %'C addre ). Similarly2 /he LSw node e /abli hing a Ne/ #OS circui/ end a namerecogni:ed frame (no/ an icanreach frame).

$LSw *low Control

LSw flow con/rol in0ol0e adaptive pacing be/ween LSw rou/er . uring /he flow5con/rolnego/ia/ion2 /wo inde3enden/2 unidirec/ional flow5con/rol mechani m are e /abli hed be/ween LSw

3ar/ner . 'da3/i0e 3acing em3loy a windowing mechani m /ha/ dynamically ada3/ /o buffer a0ailabili/y. indow can be incremen/ed2 decremen/ed2 hal0ed2 or re e/ /o :ero. Thi allow /he LSwnode /o con/rol /he 3ace of /raffic forwarded /hrough /he ne/wor1 /o en ure in/egri/y and deli0ery of allda/a.

$LSw *low-Control Indicators

+ranted units (/he number of uni/ /ha/ /he ender ha 3ermi ion /o end) are incremen/ed wi/h aflow5con/rol indica/ion (one of e0eral 3o ible indica/or ) from /he recei0er. LSw flow con/rol

3ro0ide for /he following indica/or func/ion 93 Repeat )Increments granted units by the current window size.3 Increment )Increases the window size by ! and increases granted units by the newwindow size.3 Decrement )*ecrements window size by ! and increments granted units by the newwindow size.3 Reset )*ecreases window size to + and sets granted units to +, which stops alltransmission in onedirection until an increment flow'control indicator is sent.3 Half ) uts the current window size in half and increments granted units by the newwindow size.3 Flow ) ontrol indicators and flow'control acknowledgments can be piggybacked oninformationframes or sent as independent flow'control messages. -eset indicators are alwayssent asindependent messages.

)dapti!e-"acin0 ;amples

E7am3le of ada3/i0e53acing cri/eria include buffer a0ailabili/y2 /ran 3or/ u/ili:a/ion2 ou/bound @ueueleng/h2 and /raffic 3riori/y. E7am3le of how each can be u ed /o influence 3acing follow93 Buffer availability )If memory buffers in a * Sw node are critically low, the node candecrementthe window size to reduce the flow of traffic. %s buffer availability increases, thenode then canincrease the window size to increase traffic flow between the * Sw partners.3 Transport utilization )If the link between two * Sw partners reaches a high level ofutilization,the window size can be reduced to lower the level of link utilization and to preventpacket loss


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)f we apply the +, ( color code and show all eight wires' our pin-out looks like this!


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pins 0' +' 2' and and the blue and brown pairs are not used in either standard. 3uite contraryto what you may read elsewhere' these pins and wires are not used or re4uired to implement566 (7E-T" duple8ing--they are 1ust plain wasted.

the actual cables are not physically that simple. )n the diagrams' the orange pair of wires arenot ad1acent. The blue pair is upside-down. The right ends match %/-0+ 1acks and the left endsdo not. )f' for e8ample' we in&ert the left side of the +, ( 9straight9-thru cable to match a +, (

1ack--put one 5 6: twist in the entire cable from end-to-end--and twist together and rearrangethe appropriate pairs' we get the following can-of-worms!

This further emphasi;es' ) hope' the importance of the word 9twist9 in making network cableswhich will work. ikewise' if we e8change the green and orange pairs in the +, ( diagram we will get asimplified diagram for a +, straight-thru cable. )f we cross the green and orange pairs in the+, ( diagram we will arri&e at a simplified diagram for a crosso&er cable. (ll three are shownbelow.

%t$ernet &'BaseT or &''BaseT (rossover (ableere are in /ruc/ion for building an E/herne/ 4B a eT or 4BB a eT cro o0er cable.


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The 3inou/ for an E/herne/ cro o0er cable are a follow 9

(onnector &)inout

(onnector *)inout

4 8>

; OPEN

A OPENSo 3in 4 5Q 3in 82 3in > 5Q 3in . 'll of /he o/her 3in are lef/ o3en.

The e in /ruc/ion can al o be u ed /o 3urcha e an E/herne/ cro o0er cable /o ne/wor1 your com3u/er and 3rin/er /oge/her. on / ju / buy any !F5?= cableD /he in/ernal 3inou/ for a cro o0er cable i differen/ from/he 3inou/ of an !F5?= cable normally u ed in E/herne/. %a1e ure /he 3ac1aging i clearly labeledcro o0er cable 2 or ha0e omeone crea/e /he cable for you.

$CC ha a grea/ deal on cro o0er cable .

lan( IRT*AL LOCAL AREA NETWORK)' *L'N i defined a a %roadcast domain wi/hin a wi/ched ne/wor1. roadca / domain de cribe /hee7/en/ /ha/ a ne/wor1 3ro3aga/e a broadca / frame genera/ed by a /a/ion. Some wi/che may beconfigured /o u33or/ a ingle or mul/i3le *L'N . hene0er a wi/ch u33or/ mul/i3le*L'N 2broadca / wi/hin one *L'N ne0er a33ear in ano/her *L'N. Swi/ch 3or/ configured a a


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member of one *L'N belong /o a differen/ broadca / domain2 a com3ared /o wi/ch 3or/ configured amember of a differen/ *L'N. Crea/ing *L'N enable admini /ra/or /o build broadca / domain wi/hfewer u er in each broadca / domain. Thi increa e /he bandwid/h a0ailable /o u er becau e fewer u erwill con/end for /he bandwid/h. !ou/er al o main/ain broadca / domain i ola/ion by bloc1ing broadca /frame . Therefore2 /raffic can 3a from one*L'N /o ano/her only /hrough a rou/er. Normally2 each ubne/ belong /o a differen/ *L'N. Therefore2 ane/wor1 wi/h many ubne/ will 3robably ha0e many *L'N . Swi/che and *L'N enable a ne/wor1admini /ra/or /o a ign u er /o ome of /he de0ice a//ach /o /heir wi/ch u ing acce lin1 2 while /heconnec/ion be/ween /he wi/che u/ili:e /run1 lin1 . To mul/i3le7 *L'N /raffic2 3ecial 3ro/ocol e7i //ha/ enca3 ula/e or /ag (mar1) /he frame o /ha/ /he recei0ing de0ice 1now /o which *L'N /he frame

belong . Trun1 3ro/ocol are ei/her 3ro3rie/ary or ba ed u3on #EEE AB>.4 . ,or e7am3le2 a 3ro3rie/ary/run1 3ro/ocol may be li1e Ci co6 3ro3rie/ary #n/er5Swi/ch Lin1 (#SL)2 which enable Ci co de0ice /omul/i3le7 *L'N in a manner o3/imi:ed for Ci co com3onen/ . Or2 an in/er0endor olu/ion may beim3lemen/ed2 uch a AB>.4 2 which enable 3roduc/ from more /han one 0endor /o mul/i3le7 *L'N ona /run1 lin1. i/hou/ /run1 lin1 2 mul/i3le acce lin1 mu / be in /alled /o u33or/ mul/i3le *L'N

be/ween wi/che . Thi i no/ co /5effec/i0e and doe no/ cale well2 o /run1 are 3referable forin/erconnec/ing wi/che in mo / ca e .

LAN Switching ForwardingL'N wi/che can be charac/eri:ed by /he forwarding me/hod /ha/ /hey u33or/. #n /he /ore5and5forwardwi/ching me/hod2 error chec1ing i 3erformed and erroneou frame are di carded. i/h /he cu/5/hroughwi/ching me/hod2 la/ency i reduced by elimina/ing error chec1ing. i/h /he /ore5and5forward wi/chingme/hod2 /he L'N wi/ch co3ie /he en/ire frame in/o i/ onboard

buffer and com3u/e /he cyclic redundancy chec1 (C!C). The frame i di carded if i/ con/ain a C!Cerror or if i/ i a r#nt (le /han


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i/h /he cu/5/hrough wi/ching me/hod2 /he L'N wi/ch co3ie only /he de /ina/ion addre (/he fir / < by/e following /he 3reamble) in/o i/ onboard buffer . #/ /hen loo1 u3 /he de /ina/ion addre in i/wi/ching /able2 de/ermine /he ou/going in/erface2 and forward /he frame /oward i/ de /ina/ion. ' cu/5/hrough wi/ch 3ro0ide reduced la/ency becau e i/ begin /o forward /he frame a oon a i/ read /hede /ina/ion addre and de/ermine /he ou/going in/erface. Some wi/che can be configured /o 3erformcu/5/hrough wi/ching on a 3er53or/ ba i un/il a u er5defined error /hre hold i reached2 when /heyau/oma/ically change /o /ore5and5forward mode. hen /he error ra/e fall below /he /hre hold2 /he 3or/au/oma/ically change bac1 /o /ore5and5forward mode.L'N wi/che mu / u e /ore5and5forward /echni@ue /o u33or/ mul/ilayer wi/ching. The wi/ch mu /recei0e /he en/ire frame before i/ 3erform any 3ro/ocol5layer o3era/ion . ,or /hi rea on2 ad0ancedwi/che /ha/ 3erform Layer 8 wi/ching are /ore5and5forward de0ice .

LAN Switching BandwidthL'N wi/che al o can be charac/eri:ed according /o /he 3ro3or/ion of bandwid/h alloca/ed /o each 3or/.Symme/ric wi/ching 3ro0ide e0enly di /ribu/ed bandwid/h /o each 3or/2 while a ymme/ric wi/ching

3ro0ide unli1e2 or une@ual2 bandwid/h be/ween ome 3or/ .'n asymmetric L ! s'itch 3ro0ide wi/ched connec/ion be/ween 3or/ of unli1e bandwid/h 2 uch a acombina/ion of 4B a eT and 4BB a eT. Thi /y3e of wi/ching i al o called 234233 s'itching .' ymme/ric wi/ching i o3/imi:ed for clien/H er0er /raffic flow in which mul/i3leclien/ imul/aneou ly communica/e wi/h a er0er2 re@uiring more bandwid/h dedica/ed /o /he er0er 3or//o 3re0en/ a bo//lenec1 a/ /ha/ 3or/.

' symmetric s'itch 3ro0ide wi/ched connec/ion be/ween 3or/ wi/h /he ame bandwid/h2 uch a all4B a eT or all 4BB a eT. Symme/ric wi/ching i o3/imi:ed for a rea onably di /ribu/ed /raffic load2 ucha in a 3eer5/o53eer de 1/o3 en0ironmen/. ' ne/wor1 manager mu / e0alua/e /he needed amoun/ of

bandwid/h for connec/ion be/ween de0ice /o accommoda/e /he da/a flow of ne/wor15ba ed a33lica/ionwhen deciding /o elec/ an a ymme/ric or ymme/ric wi/ch

Fra e Rela+ Frame elay i a high53erformance 'N 3ro/ocol /ha/ o3era/e a/ /he 3hy ical and da/a lin1 layer of /heOS# reference model. ,rame !elay originally wa de igned for u e acro #n/egra/ed Ser0ice igi/al

Ne/wor1 (#S N) in/erface . Today2 i/ i u ed o0er a 0arie/y of o/her ne/wor1 in/erface a well. Thicha3/er focu e on ,rame !elay 3ecifica/ion and a33lica/ion in /he con/e7/ of 'N er0ice .,rame !elay i an e7am3le of a 3ac1e/5 wi/ched /echnology. Pac1e/5 wi/ched ne/wor1 enable end/a/ion /o dynamically hare /he ne/wor1 medium and /he a0ailable bandwid/h. The following /wo/echni@ue are u ed in 3ac1e/5 wi/ching /echnology9R *ariable5leng/h 3ac1e/R S/a/i /ical mul/i3le7ing*ariable5leng/h 3ac1e/ are u ed for more efficien/ and fle7ible da/a /ran fer . The e 3ac1e/ are wi/ched

be/ween /he 0ariou egmen/ in /he ne/wor1 un/il /he de /ina/ion i reached.S/a/i /ical mul/i3le7ing /echni@ue con/rol ne/wor1 acce in a 3ac1e/5 wi/ched ne/wor1. The ad0an/age of/hi /echni@ue i /ha/ i/ accommoda/e more fle7ibili/y and more efficien/ u e of bandwid/h. %o / of/oday 3o3ular L'N 2 uch a E/herne/ and To1en !ing2 are 3ac1e/5 wi/ched ne/wor1 .


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Fra e Rela+ De,"cese0ice a//ached /o a ,rame !elay 'N fall in/o /he following /wo general ca/egorie 9R a/a /erminal e@ui3men/ ( TE)

R a/a circui/5/ermina/ing e@ui3men/ ( CE)

DTEs generally are considered to be terminating e4uipment for a specific network and typically are located on thepremises of a customer. )n fact' they may be owned by the customer. E8amples of DTE de&ices are terminals' personalcomputers' routers' and bridges. DCEs are carrier-owned internetworking de&ices. The purpose of DCE e4uipment is topro&ide clocking and switching ser&ices in a network' which are the de&ices that actually transmit data through the ?(@.)n most cases' these are packet switches. Figure 56-5 shows the relationship between the two categories of de&ices.

The connection between a DTE de&ice and a DCE de&ice consists of both a physical layer component and a link layercomponent. The physical component defines the mechanical' electrical' functional' and procedural specifications for theconnection between the de&ices. Ane of the most commonly used physical layer interface specifications is therecommended standard #%7$-B B specification. The link layer component defines the protocol that establishes theconnection between the DTE de&ice' such as a router' and the DCE de&ice' such as a switch. This chapter e8amines acommonly utili;ed protocol specification used in ?(@ networking! the Frame %elay protocol.

Fra e Rela+ "rt$al C"rc$"ts

Frame %elay pro&ides connection-oriented data link layer communication. This means that a defined communicatione8ists between each pair of de&ices and that these connections are associated with a connection identifier. This ser&ice isimplemented by using a Frame %elay &irtual circuit' which is a logical connection created between two data terminale4uipment #DTE$ de&ices across a Frame %elay packet-switched network #P7@$.

irtual circuits pro&ide a bidirectional communication path from one DTE de&ice to another and are uni4uely identified bya data-link connection identifier #D>C)$. ( number of &irtual circuits can be multiple8ed into a single physical circuit fortransmission across the network. This capability often can reduce the e4uipment and network comple8ity re4uired toconnect multiple DTE de&ices. ( &irtual circuit can pass through any number of intermediate DCE de&ices #switches$located within the Frame %elay P7@. Frame %elay &irtual circuits fall into two categories! switched &irtual circuits #7 Cs$and permanent &irtual circuits #P Cs$.


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S'"tc e! "rt$al C"rc$"ts

Switched virtual circuits (SVCs) are temporary connections used in situations re4uiring only sporadic data transferbetween DTE de&ices across the Frame %elay network. ( communication session across an 7 C consists of thefollowing four operational states!

Call set p The &irtual circuit between two Frame %elay DTE de&ices is established.

!ata trans"er Data is transmitted between the DTE de&ices o&er the &irtual circuit.

Idle The connection between DTE de&ices is still acti&e' but no data is transferred. )f an 7 C remains in an idlestate for a defined period of time' the call can be terminated.

Call termination The &irtual circuit between DTE de&ices is terminated.

(fter the &irtual circuit is terminated' the DTE de&ices must establish a new 7 C if there is additional data to bee8changed. )t is e8pected that 7 Cs will be established' maintained' and terminated using the same signaling protocolsused in )7D@.

Few manufacturers of Frame %elay DCE e4uipment support switched &irtual circuit connections. Therefore' their actualdeployment is minimal in todayGs Frame %elay networks.

Pre&iously not widely supported by Frame %elay e4uipment' 7 Cs are now the norm. Companies ha&e found that 7 Cssa&e money in the end because the circuit is not open all the time.

Per anent "rt$al C"rc$"ts

Permanent virtual circuits (PVCs) are permanently established connections that are used for fre4uent and consistent datatransfers between DTE de&ices across the Frame %elay network. Communication across a P C does not re4uire the callsetup and termination states that are used with 7 Cs. P Cs always operate in one of the following two operational states!

!ata trans"er Data is transmitted between the DTE de&ices o&er the &irtual circuit.

R I!le IThe connec/ion be/ween TE de0ice i ac/i0e2 bu/ no da/a i /ran ferred. +nli1e S*C 2 P*Cwill no/ be /ermina/ed under any circum /ance when in an idle /a/e.

TE de0ice can begin /ran ferring da/a whene0er /hey are ready becau e /he circui/ i 3ermanen/lye /abli hed.

Fra e Rela+ Net'ork I -le entat"on

' common 3ri0a/e ,rame !elay ne/wor1 im3lemen/a/ion i /o e@ui3 a T4 mul/i3le7er wi/h bo/h ,rame!elay and non5,rame !elay in/erface . ,rame !elay /raffic i forwarded ou/ /he ,rame !elay in/erfaceand on/o /he da/a ne/wor1. Non5,rame !elay /raffic i forwarded /o /he a33ro3ria/e a33lica/ion or er0ice2uch a a 3ri0a/e branch e7change (P J) for /ele3hone er0ice or /o a 0ideo5/eleconferencing a33lica/ion.

( typical Frame %elay network consists of a number of DTE de&ices' such as routers' connected to remote ports onmultiple8er e4uipment &ia traditional point-to-point ser&ices such as T5' fractional T5' or +,-=b circuits. (n e8ample of asimple Frame %elay network is shown in Figure 56- .

Figure 56- ( 7imple Frame %elay @etwork Connects arious De&ices to Different 7er&ices o&er a ?(@


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The ma1ority of Frame %elay networks deployed today are pro&isioned by ser&ice pro&iders that intend to offertransmission ser&ices to customers. This is often referred to as a public Frame %elay ser&ice. Frame %elay is

implemented in both public carrier-pro&ided networks and in pri&ate enterprise networks. The following section e8aminesthe two methodologies for deploying Frame %elay.

27596087 networking training report

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