Tong Hop Mang Thong Tin

8/8/2019 Tong Hop Mang Thong Tin

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Phn I: Tng quan v k thut chuyn mch

M u1.nh ngha: Telecom switching

CM l thit lp,duy tr, v gii fng lien kt c tnh chn la xung quanh cc g truyn dnvin thng.(hv)Trong h thg CM gm 3 qtrnh: thit lp, duy tr, gii fng.Kt ni ny c tnh chn la:- Ti 1 thi im thu bao A v B c nhu cu lin lc, hthng Cm thit lp 1 lin lc vlgia A v B. Lin kt ny c duy tr trong sut tgian trao i thng tin.- Khi A v B kt thc qtrnh trao i thng tin th lin kt c gii fng.2.Cc hthng CM:Mng vin thng: cung cp dv vin thng(h.nh, ting ni, ch vit)

Cu trc mng VT: Cc thit b u cui, Cc trung tm CM v tng i(Exchange), Cch thng truyn dn.nh ngha: Cc hthg CM l cc hthng cng ngh c s dng trong mng VT CM cccuc gi t cc u cui ca n.CM c 2 loi: CM ni ht (thu bao) Local; CM chuyn tip (trung k) Trunk.(hv)* Phn bit theo cu trc:- Vi CM ni ht c cc g thu bao v cc g trung k:+g thu bao ni t thu bao n hthg CM.+g trung k ni gia cc hthg CM.- CM chuyn tip: Ch c cc g trung k (nu c thu bao th ch l thu bao nghip v, kfc v khch hang)- i vi CM ni ht th lu lng cuc gi thp, ng ta xem cc CM ni ht nh cc trungtm tp trung v phn b ti.- CM chuyn tip l CM l lng tp trung t cc g trung k.Ch : Cc hthg CM fc v cc thu bao. Thu bao c tnh fn b ton cu. k th c 1 hthgCM fc v cho tt c cc thu bao, gii fp y l fi fn ti s c nhiu cc hthg CMv mi hthg CM th fc v 1 s lng nht nh cc thu bao nm trong vng a l of n.Cc hthg CM c ni vi nhau.S tng qut mng CM:(hv)

LSS Local Switching System: CM ni ht.TSS Trunk Switching System: CM trung k.RSS Remote Switching System: CM v tinh.STP Signalling Transfer Point: im chuyn tip bo hiu.IN Intelligent Network: Mng thng tin.T s ta thy:- C 4 CM ni ht, mi CM kt ni vi thu bao 2 cch trc tip.


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- C 4 CM LSS c ni vi nhau qua 1 CM trung gian TSS.- RSS c gi l CM v tinh hay CM thu bao xa.

Thng tin thit lp hay gii fng cuc gi c truyn qua mng bo hiu, mng qun lvin thng, tng hiu qu v tin cy ca mng. Mng thc hin 5 chc nng chnh:

- Qun l li Fault Management.- Tnh cc Accouting Management.- An ninh Security Management.- Hot ng Performance Management.- Cu hnh Confirgurator Management.Mi thnh fn of mng c cc CSDL quyt nh hng, cu hnh ca thnh fn .Cnmng qun l VT th qun l s bin thin CSDL of cc i tng.

Mng v dch v vin thng1.Mng vin thng

nh ngha: L tp hp cc trang thit b k thut cung cp dch v vin thng chongi s dng. xy dng mng vin thng cn quan tm n:- S i tng l bao nhiu- Mt phn b- Tc pht trin thu bao tng vngHai i lng chnh ny bin thin theo thi gian , thoe tnh cht ca x hi .Ngoif ta sdng d bo khoa hc xc nh 2 i tng ny bng cch xc sut thng k.* Thnh phn ca mng vin thng:a.Thit b u cui (Terminal equipment): pha ngi s dng phi c thit b a thng

tin ng s dng vo mng v a thng tin t mng v pha ngi s dng .b.Cc trung tm : thu nhp , x l thng tin tha mn yu cu ca ngi s dng .Trung tm thc hin hai chc nng c bn : chuyn mch, x l thng tinTy vo chc nng ca mi trung tm m mt tng hai l chnh hoc l h tr.c.Mng ( h thng) truyn dn:Dng lkt cc thit b u cui vi cc trung tm. ng ni t cc TE n cc trungtm c goi l cc dng dy thu bao . kt ni ny c th n gin c cu trc l mtdy i , hay c cu trc phc tp ( mng truy nhp AN _ Access Network ) cn lien ktgia cc trung tm vi nhau c gi la ng trc ( hay ng trung k)d.Phn mm ca mng:

Cho bit cc thit b trong mng c ni vi nhau nh th no hay cho bit TOPO mng .Phn mm cng nh ngha giao thc mng ,gip cho cc thit b trong mng c th traoi thng tin vi nhau .T a c phi c phn mm ca mng mi hot dng c , mng h thng mi honchnh .

2. Dch v vin thng.a.Chun ha cc loi dch v.


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(hv)UNI - User Network Interface ( giao din gia ngoif s dng v mng)

NNI - Network Node Interface( giao din gia cc nt mng)*Dch v mng thng tin:-Vn chuyn thng tin cho ngi s dng mng vin thng

-Cung cp phng tin cho ngi s dng, cho ngi vn chuyn thng tin ca h-c im :- Khng can thip vo thng tin vn chuyn qua mng. Cht lng dich j v ch ch ticht lng truyn t thng tin .- nh ngha c cc knh vn chuyn- Kh nng truy cp vo dch vDch v xa: Tng t nh dch v mng nhng phc v n tn u cui ( phc v chotng loi thng tin ) v du : dch v in thoi , truyn s liu (hv)b.nh gi cht lng phc v(QoS):

(hv)c.S pht trin ca cc loi dch v vin thng:*c im ca cc loi dch v :- Cc loi dich v u c th hin bng m thanh, hnh nh ch vit (vn bn)- Tt c cc loi dch v thng c gi quyt bng thng tin in.- Mi i tng s dng cn c nhiu loi dch v- Cc loi dch v thng gii quyt c lp vi nhau.- Vi mi loi dch v s c tng phng tin ring

Vi cch xy dng mng vin thng truyn thng th hiu qu kinh t thp v gp nhiu

kh khn khi thau i dch v. V vy hng pht trin l xy dng mt mng a dch v cung cp c nhiu loi dch v cho ngi s dng.Mng a dch v khng phi l tp hp ca cc mng khc nhau m l mt mng k thutthng nht c kh nng cung cp nhiu loi dch v , trong mng mi loi dch v cn nmt m ha (pha u dng thng tin- nh ngha thng tin truyn trn mng cung cpcho ngi s dng ). V vy mng c th cung cp nhiu loi dch v cho mt ngi sdng ( bng cch ghp knh thi gian )

Dch v truynthng

Phng tin

in thoi Mng in thoi

in bo Mng in boTruyn s liu Mng truyn s liu

a dch v Phng tinNhiu Mt

Cc dch ting ni , ch vit v hinh nh c nhiu c trng khc nhau:- Thng tin c a ch hay khng c a ch


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- Thng tin mt chiu hay hai chiu- Thng tin c nhy cm tr hay khngd.S pht trin ca cng ngh vin thng:(hv)Cng ngh truyn dn bao gm: Gia cng tn hiu; Phng tin truyn dn

*Gia cng tn hiu:Gia cng tn hiu truyn dn hay tng t hay tn hiu truyn dn s c phng phpti u.- Vi tn hiu tng t c bng thng rng v cht lng km nn ch dung trong mt slnh vc nht nh .- Hin nay la chn phng thc truyn dn s v c nhiu u im l kh nng chngnhiu cao , tuy nhin do trong truyn dn s, s mc tin hiu l hu hn , c mt s t hp

b cm khng c dung vi i vi tn hiu s. nhiu khng b tch ly cui knh thta phi dung cc trm lc lc.

Ngoi ra trong tin hieu s cn gp mt hin tng thng thy la jitter . l hin tng c

th lp li mt xung khi pht nhng thi im xut hin xung li khc nhau pha u thu.(s)Phng php ghp knh:(s)Phng php ghp knh theo tn s: cc knh khc nhau, ng ta s dng sng mang khcnhau nn cht lng mi knh l khc nhau vi tng loi thng tin . Ngy nay ngi ta sdng phng php ghp knh theo thi gian l chnh (TDM)

Nn tin hiu: tit kim knh dn ngi f ta c th dung rt nhiu cc phng php nnkhc nhau cho tng loi s liu.+Vi tn hiu m thanh : Trong qu trnh bin thin th lng khc nhau gia hai mc lin

lin k ly mu l rt thp. Do ngi ta ch li dng iu ny m ha lng khcnhau ny ri chuyn i.Vi cht luong cng cao , mc lng t ha cng hp , dn n sbit cn m ha cho s bin ng cng ln , song vn nh hn mc m ha bin .+Tn hiu video: Trong cc hnh nh xut hin lien tip th mc thay i im sang lrt nh. Do ngi ta c mt m ring ch ra rng mc thay i sang trc v sau la

bao nhiu. Ngoi ra vi cc im nh lin k thng c mc sang l ging nhau cao.Vi tn hiu video c tn s 6,5 Mhz: fN= 2.6,5=13 MHzVi tiu chun nn MPEG 2 xung cn 8 Mbps cn truyn tn hiu video

*Tm kim phng tin truyn dn tc cao:V tuyn; Hu tuyn- Hu tuyn :+ u tin s dng cp ng trn 4 ly c tn s fmax =150KHz . Khng s dng tn scao hn v cp ng trn ging nh dy anten bc x lm suy hao tn hiu v lm nhhng, lm nhiu nhng h thng khc, truyn dn ti a 16 knh thoi.+ S dng cp i xng : xon li thnh tng i mt , tng nhm mi i 4 dy , c tn sti a fmax =200KHz. Khai thc trn mt i dy 60 knh thoi , tuy nhin li c nhcim xuyn nhim tn s cao , gii php cho vn ny l ng i v v phi ring bit.+ S dng cp ng trc : t c n fmax=60MHz, vi mt s loi f c bit


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c im : Chiu ca in t trng t ngoi vo trong nn tn cao khng gy nhiu choh thng khc , nu ta chon c t l ung knh ngoi v ng knh trong thch hp thc th gim suy hao trn cp ng trc ti mc ti thiu .Trn cp ng trc c th truyn 10800 knh thoi , tuy nhin li c nhc im l suyhao ln , 152km phi khuyech i mt ln th mi m bo chat lng . t tin

+ S dng cp quang : l phng tin truyn dn l tng di tn ln ti Ghz , suy hoanh 70,80 km mi cn lp trm khuch i, khng b can nhiu t ngoi vo hay t trongra, r tin.Tuy nhin c nhc im l : cng lp t tn km do phi xy dng h thng ngm , sc

bn c hc km.- V tuyn : c th truyn sng di , cc di , ngn v cc ngn .+ Sng di cn nng lng ln mi truyn c i xa, cng sut hang trm kw mi truynvi km+ Sng ngn: cng sut nh, vi w l tuyn c i xa hang chc km. Tuy nhin nhcim Fadinh, nn t s dng trong vin thng .

+ Song cc ngn: di tn rng nhng ch truyn c theo uong thng, gi l thng tintm nhn thng.Nhc im: suy gim ln. 50km li khuyech i mt ln. gi sng ny l v tuynchuyn tip, c th thu phat bng cc v tinh, gi l v tinh a tnh .

Cng ngh chuyn mch1.Chuyn mch thu thp x l thong tin tho mn yu cu ngi s dnga, Phng thc chuyn mch knh/N: Theo y/c of ng s dng thit lp 1 knh dn cc tg trao i tt vi nhau trn kenh

dn .Qu trnh :+ Thit lp knh dn+ Duy tr knh dn+ Gphng knh dnc im+Ng s dng lm ch knh dn trg sut qtr trao i tt ca h.+ Knh dn thun tin cho vic trao i tt 2 chiu. Thi gian thc v ko c tr.+ Hiu sut s dng knh l trg khong tgian duy tr knh. V ti 1 thi im knh dn sdng cho lin lc l 1 chiuhiu sut ti a t 50%.

+ CM knh ch f hp vi cc trg hp khi tgian khi fc v thit lp cuc gi l rt nh sovi tgian duy tr cuc gi.Trong thc t we thng trang b s knh trong 1 cm bao gi cng nh hn nhu cu sdng. Vi tnh ton xc sut cc thu bao cng hng ti 1 thi im l thp.+ Tuy nhin cng c th xy ra hin tg k /ng c nhu cu ng dngcuc gi b tchitn tht.


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+ Phi c HT iu khin thit lp cuc gihthg ny c gi l hthg bo hiu. v n l 1c th gn lin vi mng CM knh.b. Chuyn mch tinL phng thc truyn tt n ch theo y/c ng dng.Qu trnh:

+Nhn tin+Gi tinc im+Ng s dng k lm ch knh dn. gy kh khn cho vic trao i tt theo tgian thc.+C c im xy ra htg tr t/h+Vic nhn v gi tt do tb hon ton m nhn cn 1 hthg giao thc trao i tt vi cctb.+Cn chun ha cho vic gi v nhn tt. Ty theo cc chun ha m ta c cc gi CM tinkhc.

Nu chun ha tt theo gi, tao c 1 CM tin in hnh l CM gi.

+Hiu sut s dng knh trong CM tin l cao.+CM tin thch hp vi truyn tt, s liu 1 chiu.(s)c. Chuyn mch giBn tin c chia thnh nhiu gi vi chiu di xc nh, mi gi c fn header mang thongtin ch v th t giMi gi i qua cc node c tin hnh theo phng php store&forward nh CM tinTi u thu tin hnh sp xp cc gi tr liTrong cc gi lun c cc trng ktra bo gi truyn khng b lic dim

Trao i thong tin theo tg thc nhng nhanh hn CM tini tng khng lm ch knh dnHiu sut caoThc hin truyn s liuKtra li tng chng, dm bo gi truyn khng b li nhng li lm gim vn tc truyn giBng thong thp, tc thpPh hp vi mng truyn dn tc thpd. CM a chc nng*khin trc tip: tt khin trc tip khin s hng ca c cu chp hnh.*khin gin tip: tt khin k trc tip khin c cu chp hnh m n c a n b nh,

sau mi c a ti c cu chp hnh.*khin theo ctrnh np sn: SPC (stored Program Control) tt khin c a vo 1 b vxl.B vxl s tng tc vi b nh a rat t khin c cu chp hnh. y l nguyn lkhin c s dng n nht hin nay.

CM theo thi gian1. S ghp knh:


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Chuyn mch thi gian l loi chuyn mch phc v s trao i ni dung gia hai khe thigian trn cng mt tuyn PCM.(s)CODEC: bin i t analog digitalMUX v DEMUX fi ng b vi nhau.

- Tn hiu m thanh c m ha qua b CODEC vi ts ly mu 8khz. T/h u ra 8 bit c di 125us tg ng vi tc 64Kbps. t/h sau b ghp knh n s c ghp tun t ti cct/im t1,t2,tn- Chu k chim knh trn lung ra HW gi l 1 khe thgian Ts. Trong trng hp ghp Nknh th di Ts = 125us/N.2.Ngl hng ca CM knh theo tgian T:- Ngl: CM tgian T, n fi trao i v tr tgian ca t/h.. Vic trao i c th/hin = cch sdng cc b nh. V ngl th.hin trao i tgian ny bao gm 2 bc:+nh v tr, tgian ca cc t/h.+i ch v tr tgian.

- Ngtc trao i khi tgian:+ trao i khe tgian c thc hin = cch lu tm cc t/hiu c truyn trn lung cao vo bnh ca CM v sau th c cc t/h c lu tr ra vi th t khc so vi khi ghi vo.(hv)VD: kt ni a vi b

b vi ac vi nn vi c(hv)* trong khong tgian TS1(t1): t/h A i n c ghi vo a ch th 1( nh th 1) ca b nh

ca CM tgian T.Cng trong khong tgian ny t/h B c lu tr nh th 2 s c c ra(t/h B c ghi vo nh th 2 trong khung trc )(hv)* trong khong tgian TS2: t/h B i n.Ghi B vo nh th 2, ng thi c t/h A nhc a ch 1 ra.(hv)* trong khong tgian TS3: t/h C i n, ghi C vo nh c a ch th 3 ng thi c t/h

N nh c a ch th n ra.(hv)Qu trnh ghi v c tip tc c t.hin an xen nhau cho n khi khe tgian cui cng ca 1

khung. Qtrnh cng c lp li cho tt c cc khung khc of cuc ni.Ch : m bo hng ca CM T th vic ghi vo v c ra t b nh CM n khng cthc hin 1 cch ng thi. Khong tgian ca 1 khe tgian s c chia ra lm 1 lt, 1 nadnh ghi v 1 na dnh c. N tg ng vi chu k ghi, c tg ng.(hv)3.Mch tng ng ca CM T:Mt CM tgian ghp n knh c m t nh 1 CM k gian vi kch thc n x n v giao imgia mch vo v mch ra s c c tg ng vi cc y/c kt ni.


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(s)4. khin CM:*khin tun t: l loi khin CM trong cc a ch ca b nh CM c phn nhim 1cch tun t khi ghi vo hoc khi c ra. Trong khin tun t, 1 b m khe tgian s c sdng thu nhn a ch ca nh. B nh ny s tng them 1 v vo gtr sau mi ln

thay i khe tgian.(hv)*khin ngu nhin: l phng thc khin trong cc a ch ca CM tgian k tg ng vith t ca cc khe tgian t TS1TSn nhng chgn c fn nhim t trc theo y/cu kt ni.Trong khin ngu nhin thi fc 1 b nh khin c sdng nhn a ch cc nh.(hv)*Phng thc khin trong thc t: l kt hp ca khin tun t v khin ngu nhin;-Ghi tun t c ngu nhin (SWRR)-Ghi ngu nhin c tun t(RWSR)5.Tham s ca CM T:

*Cu to: bao gm 2 b nh-B nh m lu thoi BM: lu tr t/h thoi.- B nh khin: CM(hv)Dung lng b nh:CBM = n.BB: s bit mang bi 1 knh( s bit trong 1 khe tgian). Nu PCM l 8 bitn: s khe tgian hoc s knh u vo.CCM = n.log2(n).

*Thi gian ghi v c:TWR= TRD = 125/(2n) (us)6.Ghp c bit //:* trong thc t cc lung t/h thp khng c u ni trc tip vi CM tgian m c ghp lithnh cc lung cao vi bc ghp ln hn sau mi a vo CM tgian.*tgian c v ghi:TWR= TRD = 125/(2n) (us)-thc t RAM: t xp x vi chc ns => nmax = 1000~2000ti a = 512 thu bao.*Phng php lm tng hiu qu ca CM T sdng pp ghp bit //.-L sp xp c t/h s ha 8 bit thnh // a vo CM tgian v truyn trn 8 g dy ring

bit.-Cc t/h ac bin i t ntip sang // qua 1 b bin i SP. KHi cc t/h c sp xp thnh //th 8 bit cho 1 knh c coi nh l 1 khe tgian v 8 g vt l t b bi c coi nh 1 lungtc cao. iu ny to ra khong trng 7 bit v khong trng c dng ghp t/h tlung cao khc.*Ngl hng ca CM T vi ghp cc bit //:-trao i khe tgian theo kiu // c thc hin = dng cc lung cao u vo v u ra. Miluong cao tg ng 8 g vt l v sdng 8 CM tgian ph.


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-trong mi 1 b CM tgian f th ch c 1 bit trong 8 bit // ca mi knh th c ghi ng thi.(s)

Chuyn mch khng gian S1.Ngl hng:CM kgian s cho fp i ch c khi tgian c cng ch s ca cc tuyn PCM khc nhau.(hv)i ch TSi-HW1 TSi-HW2

2.Cu trc ca CM S:- CM S bgm 1 ma trn vi c h thng PCM nhp v xut. truyn bt k khe tgian notrong lung PCM ca ng nhp n khe tgian tng ng c cng ch s TS ca lung PCMca ng ra. Ta thch hp ca kgian s fi c kch hot trong khong tgian ca khetgian ny.(hv)

truyn t/h ko c tr.Mi 1 ct trong ma trn c 1 b nh khinkhin ng m kt ni.tip im cu to gin bng pt AND.- trong CM S dng cc b nh khin khin kt ni.-Cc ta trong cng 1 ct c khin bi 1 b nh khin hay b nh kt ni.B nh ktni lu tr W nh = s khe tgian c trong 1 khung. Mt a ch di dng nh fn duynht c gn vo mi to trong 1 ct. i vi ct th nhta ch c ng trong khongtgian TS1 c lu tr trong nh s 1 ca b nh kt ni CM1. a ch c ng trongkhong tgian TS2 c lu tr trong nh th 2 ca b nh kt ni CM1 v tg t a chng trong khong tgian TSw c lu tr trong nh th w ca CM1.

-Dung lg ca b nh CM:y/c kch thc nh ca b nh CM fi cha 1 a ch nh fn cho mi ta trong n ta v 1 ta gi cho tt c cc tip im trng thi m ( k kt ni).CCM = w.log2(n+1).w: s khe tgian khung u vo.n: s knh u vo.*Ch :-CM kgian s S to ra 1 knh dn vl gia u vo v u ra v k c tr.-CM S k can thip v mt tgian m ch can thip v mt kgian.-trong CM S c htg vng(nghn) ni tm (blocking) xy ra khi c tranh chp bi 2 hay n

cuc gi xhin cc u vo khc nhau, nhng cng mun chim 1 khe tgian 1 tuynPCM u ra.

Khi CM dung lng ln1.Nguyn tc:-kt hp gia 2 loi CM T v S.-i ch bt k khe tgian no ca tuyn u vo vi 1 khe tgian khc ca tuyn u ra.


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(hv)-Tng dung lng trng CM vi CM T s knh ti a l 1024thit lp c 512 cuc gi.CM T n ch to ra 450 kt ni.2.Kiu kt hp:*T hoc TS: tng i c nh (vi nghn s)

-T:dng nguyn CM T lm trng CM.-TS: dng 1 fn CM T v 1 fn CM S.*TST-STS: tng i c trung bnh (hang chc nghn s)*TSST-SSTSS: tng i c ln(trm nghn s).3.Kt hp TST v STS:*TST:-trng CM T t fa ngoi.(hv)*STS:(hv)

*NX chung:-s g c la chn trong CM s cp TST s nhiu hn trong CM STS(24 v 2)-TST c xc sut nghn u vo t hn STS.-TST thng c la chn.(hv)4.CM knh thng thng:-ng dng c tng CM xem xt c th xy dng c khi CM n hg c kch thc bt k.Ty nhin trong thc t cn fi thit lp 1 knh song hng qua trng CM.-Ngtc thit lp g dn th 2 so vi g dn th 1:+g dn thu 2 c thit lp 1 cch c lp vi g dn th 1.

+g dn th 2 c thit lp kt hp vi g dn th 1.(hv)

Thit b CM knh1.Khi nim:-tb CM knh l 1 tb fc tp fi x l v thng s // trong tgian thc.N fi hng ltctrong tgian di vi t l li thp.2.S khi chc nng:(hv)3.Phn h CM:

-Knh dn: c s dng cp cho i tg trao i thogn tin vi nhau.Cc knh dn tg ng l cc lung t/h PCM 64kbps. Tng i c s knh dn nht nh tythuc dung lng ca cc ft T v S cu to nn trg CM.Thng thng cc knh dn l c lp .Tuy nhin trong trogn CM hnay cc knh dn ct chc sao cho c th nhm 1 s knh dn nht nh thnh 1 knh c tc co hn.VDmc ch cho t/h bng rng i qua trng CM.-Phn loi:


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+ Knh dn c nh(knh dn thng trc) c thit lp bi phn mm v dng kt nicc b fn trong tng i vi nhau.+ Knh dn bn c nh: c sdng to ra cc tin bo.VD bo ri, bo bn, bo li, bonhm sKnh ny sdng khi cn thit c dng trong hthg bo hiu.+ Knh dn tm thi: dng trao i tt khi knh dn ny dng xong n s c gii fng.

-Trng CM l b fn qtrng trong tng i cho nn n c cu trc d fng thch hp. Phid fng l d fng nng (1+1)trng CM gm 2 b fn lun hng ng thi, b fn chnh lun cp nht x l thng tin,

b fn d fng cp nht k x l tt. Nv d fng l k mt thng tin trong tng i.4. Phn h ng dng:-Nv phn h ng dng gip cc i tg s dng trng CM trao i tt vi nhau qua cknh nh nhau. B fn ny cn c gi l b fn fi ghp hay b fn m.-Cu trc chi lm cc khi sau:+Khi A:gii quyt vn fi ghp v fa ng sdng.+Khi B: khi trung gian

+Khi C:gii q v fi ghp v fa trng CM+Khi D: gii q v fi ghp v fa trng khin.*Khi A: ng sdng c th chia thnh nhm:-Fi ghp thu bao (thu bao tg t v thu bao s)-Trung k (tg t v s)-THu bao khc.*Khi B: lm nv ghp hoc tch knh c tp trung ti hay l k:h=M/N (hv)- h = 1: B ch t/hin ghp tch knh bthg- h > 1: B c tp trung ti

*Khi C: khin fi ghp trng CM. Ty thuc khong cch fn ra lm 1 TH:+b tp trung thu bao ti ch(thu bao u trc tip vi T)+ b tp trung thu bao xa(thu bao u qua b tp trung hoc T v tinh)- vic truyn dn gia khi C v trng CM l gin, sdng m nh fn v k cn m g dy( vi thu bao ti ch)- vic t chc truyn dn gign nh truuyn dn s thng thng. Sdng m g dy, ng

b ha, bo hiu (thu bao xa)*Khi D: n l 1 b fn trong trung tm khin T, ty theo tng trng hp m khi D cfn quyn nhiu hay t. Nhim v ca D l x l g dy thu bao, x l s b bo hiu, xl qu ti. Trong TH trm tp trung thu bao xa c dung lg ln th D c th trao nv chotrm tp trung thu bao tri thnh 1 T gii quyt lin lc ni b khi g lin lc v Tchnh b s cch lm viec trong TH nh vy gi l ch t tr.5.Phn h khin:-Cu trc khin:+n x l: cu trc c 1 b vxl+a x l: cu trc c n b vxln x l c cto gin cn 1 b vxl. ctrc fn mm fc tp, fi sdng rt n cc lnhngttc x l chm. Ch thch hp vi cc loi T c dung lg nh.


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a x l sdng n b vxl fi ghp hng vi nhau, fi c b fn khin hng ny. Ccb vxl c chuyn mn hatc x l tng cao. c p dng trong T c dung lg ln.-Phn loi:+a x l fn theo ti: ging nh n x l. Khi lg thng tin trao i gia cc vxl l thpnht. Cc vxl hng c lp d khin hn. Phn mm ftp ko chuyn mn ha c. Mi bxl fi qun l ton b fn mm T nn ch p dng cho T c trung bnh.+ a x l fn theo cnng: da vo cc cnng fn nhim: cmn ha caotng cht lgT, khin ftp hn. Phn mm c ctrc h thng, mi b xl ch fi qun l fn mm camnh. Khi lg thng tin cn trao i gia cc b xl l ln, T c ln.+ a x l fn theo module: cng gn ging fn theo chc nng: khin ftp hn. T cln.

Kt cui ng dy analogn v kt cui g dy thu bao SLTU Subcriber Line Termination Unit fi c thkchun ha v fi thc hin c 7 chc nng: B O R S C H T.B Battery Feed: cp ngunO Overvoltage Protection: bo v qu pR Ringing: rung chungS Suppervision: gim stC Coding: m haH Hybrid transformer: chuyn i 2 day sang 4 dyT Testing: kim th.* s kt ni cc chc nng:(hv)1. Chc nng B:

ng nghe trong thoi chun y/c 1 dng mnh c cp t ngun trung tm ti T ni b.dng in ny c cng t 20 100mA. Trung bnh dng c cp bi 1 b pin c in p48V c dng trung bnh 40mA.

Nng lg c cp n 2 thu bao 2 u A,B thg c ccp qua cu truyn dn. Cu truyn dnbao gm:+ngun ccp n cc thu bao qua cc cun cm khng, s t cm ca n ngn chn truyncc tn s m qua ngun trung tm. Trong T s mi SLTU t/hin 1 na chc nng cacu truyn dn.(hv)+trong b cp ngun cn c b n dng cc thu bao xa v gn u c cp 1 dng in

tg g nhau v duy tr cn bng ti trn mi mch ca T. dng in chy xuyn qua mythoi f thuc in p of ngun v tr mch vng.Zmch vng = dtr dy thu bao + tr ng vo thoi.tr dy thu bao 1250 1800tr ng vo thoi 100 200


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Mun chnh Zmch vng th ch cn chnh tr dy thu bao or tr ng vo thoi. Song doch chnh c trong fm vi nh nn ng ta chnh = cc loi dy khc nhau sao cho cng l u.+ Chng ta da vo dng trn thu bao c th xnh nhu cu thu bao. Nu thu bao c nhucu th mch vng c khp kn cn khng th mch h. Tuy nhin chgn ta cn lu s c

knh my hay chp chn g dy th fi c 1 b fn ft hin v ngt dng khi c s c, thiffi khi fc khi ht s c.2. O Overvoltage Protection:Bt k T no cng y/c s bo v trnh in p cao v dng in cao nguy him n Tv i ng vn hnh.C 2 nguy c:- St- nh hng s fn b in nngKhi c st, 1 th khong 5000V c th xhin u vo T. Bin fp l tp hp nhngdy dn of T vo 1 fin hay gi u ti khung fn fi chnh MDF chng qu p.

Cc b chng st dng ng fng in hay ht n c kt ni vi mi g dy of mch vngn mch g dy xung t khi c in p qu 750V./p nguy him c th gy ra do s tip xc in lc v cp thoi. Bi s cm ng of inlc k cn bng fa t cnh dy cp thoi.

Ngoi ra cc thit b u cui c ngun in ring, cng c th t in p nguy him bng dy. Khi b li, pp bo v l dng cu ch trong mi dy dn, Cu ch c th bo v qudng tc thi hay dp tt dng sau 1 khong tgian.Ch : bo v qu p vi nhng in p nh( vn gy nguy him cho mch) PP dngmch bin p hn bin (cch li).(hv)

3. R Ringing:1 ngun in th 2 dng theo ch ngn hn lp li rung chung cho my th rungchun thg thng ngun 75V dng 200mA v tn s 16 25Hz.Dng in chung c ft ra t b ft ngun dng trong T, c tnh gin on ca dngin chung l nhp chung thng l 2 dy m v 4 dy ng.Khi 1 my th c rung chung, g dy thu bao c kt ni vi bus dng chung vi b ftnhp(hv)S tr li thu bao c fat hin bi mch vng thu bao khi thu bao nhc my. Da trncm nhn ca mnh, b ft hin chung sai tch g thu bao ra b ft nhp chung, thithng bo cho hthg T.Hin nay t/h rung chung ch l t/h bo cho th, cn my t rung theo nhc c t ca thu

bao lu trong my.4. S Suppervision:Thc hin gim st vic t my, nhc my ca thu bao, gim st cho fp xnh 7 trngthi c bn of g dy thu bao:Hng of thu bao kin vng Tnh hung qlThu bao gi


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1.Nhc ng nghe (off hook)2.Quay s3.Gc ng nghe (on hook)

Vng c khngXung ni tipKhng duy tr vng

Thu bao giThu bao quay sKthc cuc gi

Thu bao b gi1.Cha nhc ng nghe

2.Nhc ng nghe3.ng nghe c nhc trc 4.Gc ng nghe

K c vng

To xugn duy tr vngKhi c chung, c vngK duy tr vng

Thu bao rnh

Tr liBnKthc tr li

T/h nhc my HSO:nhc my HSO = 0t my HSO = 1Gim st c dng cho thu bao, we fi dng 1 b nh m qut qua ton b N thu baoxem thu bao c nhc my, t my hay k. gim st ht s bin thin of thu bao, thtgian qut fi nh hn tc bin thin ti a ca thu bao. s bin thin trng thi nhanhnht of thu bao trng thi xung quay s. S ln chp nh of thu bao biu th qua a ch

quay s.(s)Khi khng nhc my th I(t) = 0. Khi nhc my i(t) tng t bin n mt gi tr danh nhVD: 40 mA. Sau mt khong thi gian no m i(t) = const thi ta bo knh my. Nuthu bao quay s th i(t) bin thin; ta quy c mt chu k T = 100ms, mt xung trong mts chim c 2/3 chu k tng ng 66ms, khong cch gia 2 s phi ln hn 2/3 chu k. nhn bit mi bin thin ca thu bao th chu k qut Tq phi nh hn 1/3 ch k quttng ng. (33ms) chu k qut c chun ha v c chn l 10ms.5. C-Coding (thc t m ha v gii m c tch hp vo mt IC )Code thc hin 3 qu trnh: ly mu, lng t ha v m ha.

c thc hin bi mch IC CODE(hv)Ch : mi mt code c mt cng thi gian khc nhau. Khi tp hp cc u ra ca codevo th ta c mt khung y 125s thc hin ghp knhMi mt IC c gn vi mt thu bao v n ch hot ng khi thu bao lin lc. V vycn s dng mt chn iu chnh l PD ( PD = 1 hot ng, PD = 0 khng hotng ). Gii php l ni PD vi chn tn hiu nhc, t my (HSO) ( o cc).6. H-Hybrit TransformerChuyn i 2 dy sang 4 dy ( ghp sai ng )(hv)

suy gim: a12, a34 a14, a31 nhTuy nhin cc tr khnh ny khng thc t nn mt phn quay tr li ( gi l ting vng ).V in tr cn bng ca cu cn bng khng ging nhau. m bo suy gim chng ta da vo tnh cht ca cu cn bng. iu kin cn bngl : Zcb = Z1.


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Z1 l in tr ca dy thu bao khng c nh ( thay i theo thu bao). Z 1 l tham s phnb.Zcb l tham s tp trung nn trong thc t rt kh m bo Zcb = Z1 iu ny gy ra hintng phn x tn hiu ti cc im chuyn i 2 dy sang 4 dy, hin tng ny gi lting vng.

C 2 loi : ting vng cho ngi ni v ting vng cho ngi nghe.Ting vng cho ngi ni:(hv)Ting vng cho ngi nghe: sau khi nghe v sau li nghe li pha ngi nghe.(hv)Hin tng ting vng ny ch yu xy ra khi hai thu bao A v B cch xa nhau v khikhong cch xa th m ni phn x li ln th nht ( = 2 khong cch) mi cch xa nhau vmt thi gian. ( khi khong cch ln hn 50ms trong cm nhn thnh gic u cui thngtin). trit ting vng ngi ta c th c cc phng php gim thiu ting vang:

* Phng php 1 : dng cc thit b trit ting vng. Chia lm 3 loi :1. Dng phng php t cn bng in tr trong2. Dng phng php b tn hiu3. Dng phng php ct ng quay tr v+ Phng php t cn bng in tr trong: dng b ghp Zcb t iu chnh cho ming dy cho ph hp sao cho Zcb = Z1+ Phng php b tn hiu: dng b song song vi b ghp sai ng. B b l b nhn tnhiu sau quay ngc pha ri trn vi tn hiu u v vi bin nh hn.(hv)+ Phng php ct tn hiu quay v : trn ng v th tn hiu b ct nh b xc nh

ng tn hiu ( sao cho ng dy ny hot ng th ng dy kia khng hot ng ).Phng php ny tt hn 2 phng php trn v hu nh hon ton khng c tn hiu quaytr li song n c th lm mt mt phn thng tin trao i.* Phng php 2 : Li dng tht thot trn tuyn truyn n gim ting vng.Theo tiu chun ITU th trn tuyn truyn dn phi suy hao 7dB ( mi b sai ng ngita to ra mt suy hao p dB ).(hv)S tht thot ca mch c th lm suy gim ting vng n mc chp nhn c.Trong mng quc gia analog th tht thot truyn dn vn c ngn chn ting vngcho cc cuc gi trong nc.Trong mng s kim sot v lm gim ting vng cm to ra mt tht thot truyn dn ln. i vi cc d n truyn dn quc gia, thc hin mt tht thot qua mng t nht 6dB.Tht thot ch xy ra trn tr v tn s cc cao, p ng tn s cao.7. T-Testing.Ch : mt yu cu c bn cho tt c cc tng i l kh nng kim th cho mi ng dythu bao. Thit b kim th phi c kh nng truy nhp vo bt k ng dy thu bao no.Kim th thng c thc hin bi mt rle truy nhp.


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Kim th c thc hin theo nhng nguyng tc sau.- Mi ng dy thu bao c th truy nhp v ng kim loi phi ko n thit b kimth trong thi gian kim th.- Cc kim th c th thc hin thng xuyn hay theo yu cu- Truy cp vo SLTU v thit b kim th c th qua 1 bus hay mt khi kim th ring

nh.Ch :B O R S C H T chia lm 3 nhm.

Nhm 1 : kim th cc chung v bo v qu pNhm 2 : qun l cp ngun v ghp sai ngNhm 3 : m ha v gii m cuc giMt s thu bao ghp li thnh mt card thu bao. Cc thu bao ny thng cha 8 16thu bao. Nhiu card thu bao hp thnh khi thu bao. Nhng khi thu bao thng cha64,96,128 thu bao. Nhiu khi thu bao hp li thnh mt modul ng dy thu bao1024 thu bao.

Kt ni ng trung k sn v kt ni ng dy s DLTU (Digital Line Termination Unit)Thc hin cc chc nng phi hp tn hiu s v ng pha trong s hot ng ca khichuyn mch vi mi trng truyn dn bn ngoi.S cn thit ca DLTU bao gm.- kt ni trung k ngoi vi tng i- kt ni trung k ni b gia cc phn h trong tng i. thc hin nhim v trn DLTU phi thc hin 8 chc nng: G A Z P A C H O.1.G Generation of Frame : to khung truyn dn2.A Alignment of Frame : hiu chnh khung

3.Z Zero String Supperession : trit chui xung 04.P Polar Conversion : bin i cc tnh cc tn hiu5.A Alarm Processing : cnh bo6.C Clock Recovery : khi phc tn hiu ng h.7.H Hunt During reframe : tm t m a khung8.O Office Signalling : bo hiu lin i(hv)DDF : Digital Distribution Frame khung phn b s1. Chuyn m ng dy sang nh phn.Trn cc h thng truyn dn thng s dng cc m ng dy. VD h thng cab th dng

h m lng cc HDB3 hay 4B3T, cn cab quang thng dng m 4B5B.Cc DLTU thng cung cp cc giao thc chun m tiu biu l theo CCITT G703HDB3 vi nhng lung tc 2 MbpsTt c cc m ng dy u chuyn sang m nh phn n gin ca khi chuyn mch.S chuyn i ny phi thc hin trn c 2 hng truyn.2. Chc nng ng b khung.


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Mi mt h thng ng dy s kt ni ti tng i cc khung bt u ti nhng thi imkhc nhau. cho khi chuyn mch s hot ng c, tt c cc khung phi ng b, c thchin bng cch lm tr tn hiu s t mi ng dy ca h thng mt cch va tt ccc khung trng nhau ti thi im bt u trong tng i.

Thi gian tr c thc hin nh b m ng b khung.(hv)Lung PCM c ghi vo b m vi tc knh n ( c xc nh bi n v tchthng tin nh thi ). Ti thi im u khung ca knh n. Ni dung ca b m sau c c ra vi tc ca ng h tng i, bt u ti thi im khung u tin ca tngi. S ng b ti khung l khng cn thit trong hng truyn b s nh thi v ng

b cho tt c cc ng dy c thc hin trc tip bi tng i.3. Bo v khi chuyn mch.Bo v khi chuyn mch da vo s nhn bn ca n ( hnh thc nhn bn n gin lgp i ton b khi chuyn mch ).

Cc khi DLTU thc hin cc chc nng cho c 2 mt phng song song ca khi chuynmch.+ Trong n v truyn :- To ra cc m kim tra (CRC)- To ra cc lung bit ging ht nhau+ Trong n v truyn: ???- Gim st cc m kim tra trn ng n t cc khi chuyn mch- Chn v chuyn gia cc ng dy n- Khi xng cc bo ng ch nh s thay i t mt mt phng chuyn mch nysang mt phng chuyn mch kia.

4. Kt cu truyn dn.DLTU thng dng giao tip G703, giao tip ny nh ngha mt s c tnh v in catn hiu ng dy cng nh cu trc khung. Cc kt ni thu pht Rx v Tx cng thc hinmt s chc nng nh cp ngun, truy nhp v kim th.Kt ni thu Rx cn c chc nng pht hin mt ng b khung v thc hin th tc phchi

Ngoi ra Rx cn c th gim st t l li trn tuyn truyn dn s bng cch pht hin sgin on ca cc t ng b khung.Thng thng cnh bo xy ra khi t l li bit l 10-5, 10-4 hay 10-3 (BER).

Kt ni g dy thu bao s( D/SLTU)Cc thu bao analog chim t l cao t 90 - 95%, phn cn li l thu bao s. Thu bao sc kt ni vi tng i thng qua D/SLTU. y xem xt mt kt ni thu bao inhnh cho thu bao s l ISDN vi tc 2D + B.Knh B 64KbpsKnh D 16Kbps tc BIR = 144 Kbps = 2D + B = (64x2) + 16S khi D/SLTU.


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(hv)Ch : dy ni t NTU ti tng i vn l mt i dy nhng c tc bt ln hn( 144Kbps) ca tn hiu in thoi s ( 64Kbps)H thng iu khin bo hiu thu bao c nhim v tch lung 64Kbps v thng bo skhc nhau gia SLTU v D/SLTU l:

-Mt s chc nng trong 7 chc nng B O R S C H T s c cung cp bi khi NTU-Ghp sai ng v CODEC c t trong TA. Dng rung chung khng c cp nin thoi, thay vo l thng ip c gi ti TA. Sau TA cung cp dng rungchung.-NTU cung cp mt giao tip d liu chun cho u cui. VD giao tip X21 khng c binp sai ng cho thit b u cui v chng lin kt vi NTU theo cc dy chuyn v nhnring bit.

Thu bao a dch v ISDN1. im tham chiu

(hv)Ti im tham chiu tn hiu phi t c mt chun nht nh. Thu bao ISDN khngthng qua mt i dy ni n tng i m qua mt khi thit b. Khi thit b ny baogm nhiu thit b. Vic chun ha chi tit cho tng thit b gp nhiu kh khn. Nnkhng quy c chun cho tng thit b m phi chia lm nhiu nhm chc nng. Gia ccnhm chc nng c cc im tham chiu ( im chun ). Ngi ta tin hnh chun hanhm chc nng ti thi im tham chiuMi nhm chc nng c th c mt hay nhiu thit b, khng quy nh s thit b trong minhm chc nng (NCN) m ch quy nh u vo, u ra mi nhm.2. Cc tiu chun ( knh chun) trong ISDN.

Knh B :-Tc 64Kbps- Dng m ha ting ni ( theo chun PCM ) hay cc loi m ha- Truyn d liu- Dng ghp knh cho tn hiu thoi hoc tn hiu d liuKnh D : tc 16 Kbps hay 64 Kbps. Dng cho cc tn hiu bo hiu ngi s dng

phc v cho cc kt ni truyn s liu hay chuyn mch knh. Ngoi ra knh D cng c thtruyn cc tn hiu o lng v cc tn hiu ng gi tn hiu thp.Knh H0 : tc 384Kbps (= 64B). Dng cho tn hiu VIDEO chun hoc truyn AUDIOhigh quality ( cht lng cao)

Ngoi ra cn mt s kng khc.-H11 : tc 1536 Kbps (~24Kbps) dng cho chun ghp T-H12 : tc 1920 Kbps (~30Kbps) dng cho chun ghp EChun T : Nht M 24 knh T1Chun E : Chu u 30 knh E1dng mang tn hiu bng rng bt k hoc mang nhiu knh H0Da trn t hp cc knh B v D c th to ra cc tc truy nhp khc nhau.


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Ch : 8 knh mi c mt knh D, do vic t chc truyn dn phi gii quyt vic tranhchp knh D khi nhiu TE cng mun truy nhp knh D. gii quyt ngi ta a ra khinim bit E iu khin vic tranh chp knh D.Khi TE gi bt D cho NT th NT phi gi li mt bt E cho TE. Khi TE no nhn c bitE mi gi thng tin. Quy nh mt TE phi nhn c mt lng bit TE no mi c

gi thng tin i s dng b m bit E. VD : t TE b m bit E = 5 vi c ch m li,khi no b m =0 TE mi c gi thng tin.Truyn dn trn giao din U s dng 2 dy.Giao din U ni gia NT vi NT. Vic t chc truyn dn trn ng dy ni 2 dy, tchc truyn dn theo 1 trong 2 cch :-Ghp knh, nn thi gian-Dng b trit ting vngGhp knh nn thi gian : lun phin bin thin chiu pht, chiu thu trn i dy ccdng bit khng va chm vo nhau.Ch : ta c th chia khe thi gian thnh 2 phn : mt phn dnh cho pht, mt chiu dnh

cho thu, thc t cn mt khong thi gian chuyn t pht sang thu v ngc li do phi chia lm 3 phn, 1/3 cho pht, 1/3 cho thu, 1/3 cho phng v. tng bit trong khungtruyn dn l 32 bit, dng cho pht 10 bit, thu 10 bit v 12 bit cho phng v.Ch : do vic ghp knh nn theo thi gian nn tc bit tng ln 256bps ( 4 ln ) nnkhong cch NT v ET gim xung.Dng b trit ting vng bin p sai ng 2 u NT1 v NT lm bin i tn hiu.(hv)Tc trn ng dy thu bao khng b tng nn khong cch NT v tng i vn cm bo. di ng dy thu bao trong bin p sai ng c th tng gp i so vi ghpknh nn. Tuy nhin trn ng dy thu bao ngi ta s dng m 2B1Q nn bin p phi

hot ng ph hp vi m ch to kh khn2B1Q 4 ngng vi 2 bit u vo:10

+3

11

+1

01

-1

00

-3

4. Truy nhp tc c s cp PRL(hv)PRI = 30B+D=B=64Kb/s or =D=64Kb/sS dng NT2 truyn trn giao din U l 4 dy

NT1 ch thc hin chc nng ca lp 1 cn NT2 thc hin chc nng ca cc lp 1,2,3 thchin c truyn dn v chuyn mch c s dng nh b chuyn mch a phng.S/T vi tc truy nhp c bn PRT cn truyn dn trn giao din U s dng cu trc30B+D tng t nh truyn dn tn hiu PCM ghp knh 30/32. Tuy nhin vic s dng


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nhng khe thi gian cho vic bo hiu l khc nhau.Trong lung PCM s cp khng quynh mi rng buc gia cc khe thi gian TS, cc TS c s dng c lp. Cn trongPRI c s rng buc gia cc khe thi gian. Chng ta c th nhm nhng khe thi gian li to thnh tc cao hn

Thu bao s ADSL1.Tng quan v cng ngh ADSL:Bt i xng: Tc nhn tin v gi tin khc nhau. iu ny ph hp vi vic s dngInternet: Thng ly tin nhiu hn gi tin.Ch :- ADSL l cng ngh DSL bt i xng c pht trin t u nm 90 kh9o xut hin nhucu truy nhp Internet tc cao, cc dch v trc tuyn, hay video theo yu cu.- ADSL cung cp tc truyn dn khng i xng ln ti:+15Mbps lung xung (Tng i- Thu bao)

+15Mbps lung ln (TB-T)Tc ny ty thuc vo cch m ha v thng thng l:*Tng i Thu bao: 8Mbps*Thu bao Tng i: 640Mbps- ADSL cho php khch hng s dng 1 ng dy cho c 2 dch v thoi v truyn sliu.+Dch v thoi dng tn s: 0,3-3,4Khz+Dch v truyn s dng tn s : 4,4Khz-1Mhz- Trong ADSL c 1 b phn tch(Splitter) c t 2 u ca 1 mch vng tch tnhiu thoi v s liu theo mi hng.

2. S khi ca mng ADSL:(hv)a.Phn mng v pha nh cung cp:- H thng qung b s(Digital Broadcast) l h thng s liu hot ng ch n cng(Thng l truyn hnh qung b).- Mng bng rng l h thng chuyn mch vi tc ln hn 1,5-219Mbps(T1/E1 chun).- Mng bng hp l h thng chuyn mch vi tc nh hn 1,5-2Mbps(T1/E1 chun).- Mng qun l cho php nh cung cp gim st hot ng ca mng- Mng truy nhp AN( Access Node) l thit b chuyn i hay tp trung ti ca mngADSL. Chc nng ca AN c th bao gm c vic dn knh v phn knh tit kim

ng truy nhp vo cc mng dch v.Khi AN c gi l DS-LAM (DSL Access Mutilplexer)- ATU-C: B thu pht ADSL pha nh cung cp dch v, thc cht l 1 modem lmnhim v iu ch tn hiu cho ph hp vi knh truyn. ATU-C c th kt hp c vont truy cp mng.ATU-C (ADSL Transmission Unit at the Central Office End )- PSTN: Mng chuyn mch thoi cng cng.


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- Splitter l b lc phn tch pha nh cung cp c nhim v tch tn hiu thoi thngthng ra khi tn s cao, ngn khng cho tn hiu ADSL truyn ti thit b thoi cng nht thit b thoi truyn ti ATU-C.- Loop l mch vng, ng dy thu bao cp ng 2 dy.

b.Phn mng v pha nh thu bao:

-ATU-R l b phn thu pht ADSL t pha nh thu bao(Modem). ATU-R (ADSLTrasmission Unit at the Remote End)- Mng phn b s liu pha thu bao lalf h thng kt ni ATU-R ti cc modul dch v,cu hnh. Kt ni c th P2P hoc PMP, c th l mt ng dy ni hay mt mng tchcc.- TE: Thit b u cui.- HUB: l jack cm chun J45(hv)c.K thut iu ch trong ADSL:Theo quy nh( Chun) T1.413.1995 ca ANTS( Vin tiu chun quc gia M). K thut

m ha ng truyn s dng mt trong cc phng php m ha iu ch sau:-QAM: iu ch bin cu phng-CAP: iu ch bin pha khng s dng sng mang-DMT: iu ch a tn ri rc.*QAM: Quadrantude Amplitude Modulation:QAM s dng cc cp sng mang iu ha cng tn s, vung pha vi nhau truynthng ca 1 knh s liu. Cc nhm bit ca tn hiu u vo sau khi qua b bin i QAMs thnh k hiu(Symbol) c bin v pha c trng. Lc biu th s quan h tngng ca nhm bit u vo vi cc cp ca sng mang thnh phn th c gi l2nQAMConsteltation.

V d: lc 16QAM Consteltation(hv)S khi iu ch QAM(hv)Tn hiu u ra: V(t)= XiCost+ YiSintXi.Yi: Bin (C du v ln) ca nhm bit th nht.*DMT: Discrete Multitone-iu ch a tn ri rc

Nguyn tc: Dng bit tc cao c chia thnh mt s lung bit c tc thp hn. Midng bit tc thp c iu ch ln mt sng mang c c tn s ring ly t bng tn c phn phi.Phng php iu ch y dng QAM hoc CAP. Tng hp sng mang thnh tn hiuduy nht ri truyn i. Nh vy v bn cht DMP l s pht trin mang tnh k tha caQAM hay CAP.(hv)Ch : Ton b di thng t 0-1,1MHz c chia thnh 256 knh ph, rng mt knh

ph bng 4,3125KHz(s)Phng n 2: S dng c im nhn th khng pht m pht th khng nhn.


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i vi 2 phng php knh 16 dng cho tn hiu thoi. Khi s dng phng phptruyn song cng c b trit ting vng EC c 250 knh ph cho ng xung v 32knh cho ng ln. Nu chng ta s dng ghp knh theo tn s FDM th ch c 32 knhcho ng ln v 218 knh cho ng xung.(hv)

Ch : m bo thu c cc knh cng 1 lc th tn s sng mang ca cc knh phphi chn 1 cch khng ng nht nhng li ph thuc hm vo nhau. tn hiu gia ccknh ph khng nhiu ln nhau th h s sng mang ca chng phi i mt trc giao. tha mn yu cu trn cc tn s cp sng mang sin v cosin ca mi knh ph c ly

bng nguyn ln tn s chn trc.

Phn II: Bo hiu c bnTng quan v bo hiu

1/ Tng quan:n: Trong thng tin in thoi, bo hiu c ngha l chuyn v hng dn thng tin t 1im ti 1 im khc thch hp thit lp, gim st v gii phng cuc gi.Tn hiu bo hiu c th chia lm 2 loi:

- T/h mch vng thu bao, t/h t thu bao n tng i.- Bo hiu gia nhng tng i, t/h bo hiu gia nhng HT chuyn mch.

(s) bo hiu mch vng sub & chuyn tip.Chuyn tip CAS & CCSCAS: bo hiu knh lin kt (tt)CCS: bo hiu knh chung (s ho)2/ Cc ch bo hiu:a/ C DC:L cc m bo hiu s dc to nn da vo s kho st dng 1 chiu trn mch:

- S tn ti c hay ko ca dng in trn mch vng thu bao- Chiu ca dng in trn mch vng.

VD: gi xung quay s t thoi tng i.b/ C AC:T/h bo hiu dc to ra t t hp dao ng xoay chiu (thng l t hp ca 2 d n sc).

Ngoi ra cn c 2 loi bo hiu trong c ny: c bo hiu trong bng v ngoi bng(bng tn thoi).(s)

Nu bo hiu nm ngoi khong c bn 0.3-3.4MHz th ta c bo hiu ngoi bng. Ngc li

l trong bng.c im: Bo hiu trong bng s c khong tn s SD ln hn bo hiu ngoi bng. Tuynhin bo hiu trong bng s gy kh khn trong vic truyn t/h thoi. vi bo hiu ngoi

bng th ch cn dng 1 b LTT tch ring 2 t/h (thng ch dng bo hiu trong khong0-0.3MHz, cn khong 3.4-4KHz phi dng LTD). Ngoi ra bo hiu trong bng c b lc

phc tp hn.VD: Outband (b m)


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Inband (T cng cng)c/ C digital:(s)Cc t/h bo hiu s dc m ho bng cc bit, cc bit c th nm cng trong khung truyn dnvi tn hiu thoi hoc ko. Vi cc bit mang t/h thoi (khe thi gian bao gm c t/h thoi

ln t/h bo hiu) th gi l bo hiu trong khe. Nu cc bit chim 1 khe thi gian ring bitc nh th gi l bo hiu ngoi khe.3/ Bo hiu mch vng thu bao:a/ Th tc kt ni:(s) A---(x)---B

Nhc myMi quay sQuay s t/h hi chung(m thoi)

kthc kthcThu bao nhc my a t/h n tng i cho bit thu bao mun thit lp cuc gi. Tngi gi cho thu bao t/h mi quay s, sau thu bao c th quay vi s mong mun. Saukhi quay s xong, thu bao thu dc t/h cuc gi (t/h hi chung, bo bn hay 1 s t/h khc).Thu bao t my gi t/h kt thc cuc gi n tng i.Cch gi s thu bao n tng i: C 2 cch.c1: Gi xung quay s (pulse): s gi dc th hin bng 1 xung 1.1: gi 1 xung2: gi 2 xung

0: gi 10 xung(s)

c2: Dng m a tn DTMF (dual tone Freq): gi s thoi bng t hp 2 d n sc bohiu trong bng.f= f1 + f2f1 f2 l 2 hm thuc khong 0.3-3.4 KHz(s)4/ Bo hiu gia cc tng i:T/h bo hiu dc chia lm 2 phn:

- Bo hiu b ng k: dc SD trong thi gian thit lp cuc gi chuyn giao a chv thng tin- T/h ng dy: dc SD trong ton b cuc gi gim st trng thi ng dy.

(s) T --- Tchimcon s ca B B tr li


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(m thoi) Xo ngcXo thun5/ Truyn thng tin bo hiu trong mng:Cc cch truyn:

- Truyn theo tng chng (link by link)- Truyn theo xuyn sut (end to end)

(s)R: thanh ghiS: b phtXt cuc gi qua mng chuyn mch: thc hin cuc gi, thu bao bn gc c thanhghi lu tr thng tin a ch, sau tng i phn tch l ni ht hay chuyn tip. Nu lni ht th chuyn mch s thit lp ngay cuc gi. Nu l chuyn tip th cn s dng thm

b pht S.C 2 cch gi thng tin:

- Gi ht thng tin sang h thng chuyn mch tip theo, v qu trnh nh vy din racho n ch. Kiu truyn ny gi l truyn tng chng.

- Thanh ghi h thng chuyn mch gc ch gi thng tin xc nh ch cacuc gi. Sau khi xc nh dc ch s gi ht thng tin t tng i u n tng icui. Truyn nh vy gi l truyn xuyn sut.

6/ Bo hiu knh lin kt CAS (tt):Cc t/h bo hiu s i cng ng t/h thoi trn cng ng truyn dn. c trng ca loi

bo hiu ny l i vi mi knh thoi c 1 ng t/h bo hiu xc nh r rng. ng thoi, ngha l cc tn hiu bo hiu dc chuyn giao knh thoi. (VD bo hiu

trong bng). knh lin kt, ngha l cc t/h bo hiu dc chuyn giao knh bo hiu tch bit (VD:vi cch sp xp a khung PCM th t/h bo hiu dc chuyn giao khe th 16)(s)7/ Bo hiu knh chung CCS (s):Cc loi t/h bo hiu s dc tch ra khi t/h thoi, dc thay bi cc bn tin, v c truyn itrn 1 ng truyn dn chung, dc t chc thnh 1 mng gi l mng bo hiu.Cc t/h bo hiu cho nhiu mch c th dc x l bi 1 s cc knh s liu bo hiu tc cao. Bo hiu dc thc hin c 2 ng vi 1 knh bo hiu cho mi hng. Cc t ngdi SPC cng vi cc knh bo hiu s dc to thnh mng bo hiu ring bit.

(s)VD: Bo hiu s 6 CCITT: ch yu dng cho lu lng analog - quc t 1968.Bo hiu s 7 (SS7) t/h dc s ho hon ton 64Kbps mng quc gia v quc t(SS7 signal system N7)Mng bo hiu s 7 dc thit k iu hnh thit lp v gim st cc cuc gi thoi v sdng cho c cc cuc gi ca dch v phi thoi.ng dng: Dng cho mng PSTN (chuyn mch thoi cng cng), ISDN (s a dch v),IN (net thng minh), PLMN (thng tin di ng mt t).


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SS7, thng tin bo hiu dc truyn ti cc khi tn hiu, trong cc t hp bit c ngha khc nhau. Thc cht SS7 l 1 dng thng s liu chuyn mch gi. y c 3 loit/h ca SS7: MSU, LSSU, FISU.

- MSU: l khi tn hiu tin bo - cha cc thng tin bo hiu.- LSSU: l khi bo hiu trng thi knh dng, khi ng lin kt v iu khin

lung.- FISU: l khi tn hiu lm y, dc SD lm y cc t/h. c truyn bt c khi

no thy ko thch hp truyn cc n v khc. c SD truyn gia 2 SP khiSP ko c ni dung bo hiu kim tra tnh sn sng ca ng truyn.

Khun dng ca cc bn tin:(s)MSU: F|CB|SIF|SIO|\|LI|EC|FLSSU: F|CB|SF|\|LI|EC|FFISU: F|CB|\|NI|EC|FF: c hiu (01111110)

C bo hiu bn tin ny l c kt thc bn tin kia. trnh t hp thng tin ging c hiu,ngi ta c thut ton chn 1 bit 0 sau 5 bit 1 lin tip trong t hp thng tin.CB: Check byte: kim tra li (cha m CRC)SIF: trng thng tin bo hiu (cha thng tin bt u v kt thc cuc gi).SIO: Octet thng tin dch v (ch ra phn ngi SD).LI: phn t ch th di.LI = 0: khi FISULI = 1-2: khi LSSULI > 2: khi MSUFIB: bit ch th hng thun

FSN: s trnh t hng thunBIB: bit ch th hng nghchBSN: s trnh t hng nghch5/ Mng bo hiu:CCS cung cp 1 kh nng pht trin ca mng bo hiu ring.u im ca mng bo hiu:

- Tn dng dc ton b nng lc bo hiu ca h thng.- Tit kim chi ph xy dng mng.- To linh hot trong cc mng bo hiu.

Cc phng thc kt hp knh bo hiu CCS vi knh thoi (kiu bo hiu khcnhau)

- Kiu bo hiu kt hp: t/h bo hiu dc truyn trn lin kt ni trc tip 2 tng ivi nhau.

- Kiu bo hiu ko kt hp: cc cng vic bo hiu gia A v B dc nh tuyn thngqua 1 vi lin kt bo hiu. Tu vo iu kin mng vo thi im . Trong khimch ti dc nh tuyn trc tip t A B.


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- Ta kt hp: y l trng hp gii hn ca ch ko kt hp. Cc thng ip bohiu gia A v B i theo 1 ng nh tuyn xc nh thng qua 1 vi lin kt

bo hiu trung gian. Trong khi mch ti vn dc nh tuyn trc tip t A B.Khi ti gia 2 tng i ln: dng CCS kt hpDng d phng: nh tuyn li bo hiu CCS trn knh bo hiu ta kt hp.

Nguyn tc XD mng bo hiu:Cp STP: nng cao tin cy, cc STP thng lm vic vi nhau thnh tng cp.Thng th lu lng bo hiu dc chia gia 2 STP trn cng 1 ti chung. Trong trng hpc s c 1 STP th STP khc phi c kh nng x l tt c cc lu lng bo hiu ccSTP c s c.i vi 1 s quc gia th cu trc phn lp vi 2 mc STP thng dc chn lm gii php lp k hoch mng bo hiu.(s)6/ So snh SS7 vi m hnh OSI:(s) SS7:

lv1: Knh s liu bo hiulv2: Knh bo hiulv3: Mng bo hiulv4: SCCP TC (gm c ISP & TCAP)SCCP: phn iu khin kt niTC: kh nng giao dch

ISP: phn dch v trung gianTCAP: phn ng dng kh nng giao dchH thng bo hiu SS7 c 4 lp th 3 lp thp nht to thnh phn chuyn giao tin boMTP, lp th 4 l UP, cha cc phn t ca ngi s dng, trong m hnh OSI m t s

trao i nh hng u ni s liu (tng ng lp 4 7).

SS7 trong mng PSTN1/ Thnh phn:C 2 thnh phn:

MTP: chuyn giao tin bo hiu gia cc tng i in thoi.TUP: ngi s dng in thoi c nhim v to ra tn hiu bo hiu tng i gi thu vdch v tng i b gi.2/ Phn chuyn giao tin bo:C cu trc thnh 3 lp.

a/ Knh s liu bo hiu (mc 1)Mc 1 tng ng vi lp 1 trong m hnh OSI. N cung cp cc chc nng vt l, l

phng tin truyn cc dng bit thng tin t im ny n im khc thng qua kt cuivt l. y ko c yu cu no v cu trc thng tin ngoi cung cp thit b truyn dn.b/ Cc chc nng knh bo hiu (mc 2)Cung cp chc nng ca knh bo hiu:

- Kim sot li


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- Khi ng lin kt- Gim st t l li- iu khin lung- Phn nh ranh gii

Kim sot li da vo cc m kim tra CRC & ktra li ti u thu, nu pht hin li, bn

pht s phi pht li thng ip.Khi ng lin kt bng cch dng thng ip iu khin cc trng thi xnh.Gim st: gim st t l li bng thut ton go r m s li & s m s gim 1 lngnht nh tu thuc vo s thng ip tt. Khi s m t dc 1 s lng nht nh th linkt xem nh ko iu kin phc v, n s b loi b & thng bo cho mc 3.iu khin lung ngn chn tnh trng qu ti u thu, thc hin bng cch gi li bonhn & thng bo pht bit lin kt ang b nghn.Phn nh ranh gii bng c hiu. Mc 2 m bo ko 1 t hp bit no ging c, dc thchin bng cch ktra dng bit, nu c 5 bit 1 lin tip th chn thm 1 bit 0 vo.c/ Mng bo hiu (mc 3)

Cung cp trn mng bo hiu, c th cung cp chc nng nh tuyn cho bn tin bo hiugia cc SP v cung cp chc nng cn thit qun l mng bo hiu.Nguyn tc nh tuyn: d vo m ca im bo hiu PC (Point code)Mi 1 bn tin bo hiu cha 2 m:

- M OPC: m ca im ngun- M DPC: m ca im ch.

di PC: 14 bit.Khi SP nhn 1 bn tin th n so snh DPC v PC ca chnh n. Nu 2 bn tin ging nhauth im SP l im ch v n chuyn bn tin ny ln phn ca ngi SD. Nu 2 bn tinkhc nhau th n chuyn bn tin bo hiu sang 1 SP khc da vo bng nh tuyn ca n.

Qun l mng bo hiu: Tt c nhng th tc phi c nh: phc hi lin kt, nh tuyncho ti to nn 1 tp hp cc chc nng qun l mng bo hiu.3/ Ngi SD in thoi (TUP)Phn ca ngi s dng s nh ngha cc t/h iu khin gi dc dng gia cc SP.nh dng TUP:(s) MSU: ||SIF||trong SIF: |cc t/h a ch| s cc t/h a ch| cc khi ch th tbo| D| A cat| H1 |H0 |

Nhn|Phn loi phn cuc gi (A cat)000010 nhn vin khai thc.

001010 thu bao thng.Khi ch th tin bo (ch ra ni ht hay quc t), xxxxx1000111 s quc t u ni vtinh.S cc tn hiu a ch: s cc con s trong trng a ch.Cc tm hiu a ch biu th con s: VD: 0011 s 3. H0 m tip u nhm bn tin. H1m tip u bn tin.VD: FAM (tin bo a ch thun) H0 = 0001.IAM (tin bo a ch ban u) H1 = 0001.


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MSU dc quy chun t (Q721 Q725) ca CCITT.

Tun t gi TUP gia cc tng i:(s) TA (x)-----(X)-----(x) TTSquay s IAM IAMACM ACM(ring tone)tr li tr li(tnh cc)y/c xo y/c xo xc nhn xo xc nhn xo4/ SCCP: phn iu khin kt ni bo hiuChc nng: cung cp cc dch v to iu in vn chuyn linh hot cc thng ip bohiu. Tng cng kh nng nh tuyn ca thng ip & phng tin to mi lin h giacc thng ip nh thit lp 1 kt ni bo hiu.Phng php nh tuyn SCCP:

- Da vo ch s ca HT con nh ch cho 1 thng ip.- M bo hiu PC (ging MPC)- Dch tiu ton cc GTTPhng php ny tha nhn 1 s nh tuyn da vo m PC hay l ko.Phng pho cho pho cc ch s gc sang m bo hiu.

Ch s gc thng thng l s ca thu bao, cng c th l cc lc nh s cho d liucho mng telex, thng tin di ng hay dch v tr tin trc.Cu trc ca SCCP:Cc chc nng ca SCCP dc thc hin theo kiu module trong cc qu trnh ng dng

AP s l module iu khin phn t dch v p dng thch hp (pt p dng thch hp gil ASE) khi ng v iu khin thng tin tn hiu.

AP (application process):(s) AP(iu khin , trao i thng tin) TCTrong TC c AE & ISPTrong AE c TCAP & ASE1ASENTC: kh nng giao dchAE: pt ng dngASE: pt ng dng dch v thch hpTACP: phn mm ng dng c kh nng giao dch.

ISP: phn dch v trung gian TC:

TC gm AE v ISP. Trong AE c TCAP v ASE.TC cung cp c s thit lp thng tin gia 2 im trong mng bo hiu m ko lin quann kt ni chuyn mch ca knh.TCAP: bao gm cc nguyn tc tng qut dc p dng bt k loi bo hiu no.


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ASE: pt ng dng dch v thch hp l module iu khin cho 1 ng dng no . N thc hin 1 chc nng dc ch th nh bi AP, 1 ASE cn to ra 1 thc th thch hp tothnh t macro dc chn t th vin chung.TCAP cn h tr cho phn ng dng di ng cho h thng GSM.

Phn III: Mng s lin kt dch v bng rng B-ISDN

1/ Gii thiu:S ra i ca B-ISDN:

Nhc im ca mng VT:- L cc mng tn ti ring r, vi mi dch v thng tin li c 1 mng ring phc

v n.- Khng linh hot, km hiu qu trong vn hnh, bo dng, s dng ti nguyn.

Nguyn nhn ra i B-ISDN:- Cc yu cu v dch v bng rng tng cao.- Cc kthut x l t/h chuyn mch, truyn dn, x l t/h tc cao- S pht trin ca cc ng dng phn mm.- S cn thit t hp cc dv ph thuc ln nhau chuyn mch knh & chuyn mch

gi vo 1 mng duy nht.- Tho mn tnh mm do cho cc yu cu ca ngi SD cng nh qun tr mng.

/n theo ITU_T:B-ISDN cung cp cc cuc ni thng qua chuyn mch v cung cp dch v theo yu cu.Cuc ni trong ISDN phc v cho c dch v chuyn mch knh, chuyn mch gi theokiu a phng tin, n phng tin, theo hng lin kt hay ko lin kt v theo cu hnhn hng hay a hng.

Tm l B-ISDN l 1 mng thng minh c kh nng cung cp cc dch v ci tin: cung cpcc cng c bo dng v vn hnh iu khin, qun l mng 1 cch c hiu qu.2/ Phng thc truyn ti ko ng b ATM:K/n: ATM l phng thc truyn ti m khi thng tin xut hin u vo ca h thngdc truyn i 1 cch ko ng b, khi xut hin, thng tin s dc np vo b m sau dc ctnh thnh cc t bo v truyn ti qua mng.Thut ng ko ng b gii thch cho 1 kiu truyn trong cc gi trong 1 cuc ni cth lp li 1 cch bt thng, nhng lc chng dc to ra theo yu cu c th m ko theo chuk.VD: So snh STM & ATM:

Trong STM (truyn ti ng b), cc phn t s liu tng ng vi 1 knh cho dc nhnbit bi v tr ca n trong khung truyn.Trong ATM cc gi thuc v 1 cuc ni li tng ng vi knh o c th v c th xuthin bt k v tr no trn khung truyn.3/ ATM:

c im ca ATM:


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ATM s dng cc gi kch thc nh c nh, gi l cc t bo ATM. Cc t bo nh vitc truyn dn ln s lm cho tr truyn dn v bin ng tr (jitter) gim nh vicc ch thi gian thc. Ngoi ra tr nh lm cho vic hp knh tc cao d dnghn.Cc t bo s dc truyn ti trong khong thi gian nht nh. Ko c khong trng gia cc

t bo v trong khong thi gian ri th nhng t bo ko dc gn s dc truyn i. Th t tbo bn thu dc m bo nh bn pht.ATM m bo lin kt truyn t bo vi thng tin dc to ra ko lm lng ph dung lngng truyn dn.ATM cung cp kh nng ghp knh thng k(s)Ch : Kh nng ghp knh i lin bn cht ca t bo, to iu kin d dng t hpcc tn hiu khc nhau trn cng 1ng truyn. Trong TH c nhiu ngun VBR truyntrn cng 1 ng truyn th kh nng tng hiu qu ghp knh thng k l rt ln.iu khin li:

Trong chuyn mch gi da trn giao thc HDLC, thc hin iu khin li y trntng chng lin kt mt.Khi truyn dn dc ci thin, vic dkhin li dc n gin ho trn cc chng (b bt 1 s thtc) v khin li y ch thc hin gia u cui v u cui.(s)B-ISDN: chc nng iu khin li ko thc hin cc nt chuyn mch na. M trong tngtrng hp cn thit n dc cung cp thit b u cui, do vy cc chc nng cng dc gimti thiu nt chuyn mch ATM. iu ny gip tc truyn tng ti 600Mbit/s.(s)Nhc im: Hn ch ca phng thc truyn dn ATM:

S bin thin tr t bo CDV to ra bi cc gi tr tr khc nhau xut hin trong mngto nhng im chuyn mch v thit b ghp knh. iu ny dn n khong cch gianhng t bo thay i. N nh hng ti cht lng dch v nhy cm i vi tr.Thi gian tr t hp t bo: thng tin t ngun tn hiu s phi np ti cc b m cho nkhi t bo np 48 byte mi dc truyn i. Thi gian dc np gi l thi gian tr t hp t

bo. Thi gian np li ph thuc tc thng tin n.VD: thng tin thoi 64kb/s thi gian np 6ms.

K thut truyn ti khng ng b ATM1/ M hnh giao thc chun:

M hnh giao thc chun dc XD theo m hnh 7 lp ca OSI, bao gm 3 mng chnh.Mng khch hng: Dng cho truyn ti thng tin khch hng.Mng iu khin: Dng iu khin cuc gi v kt ni, dc cu trc thnh 3 lp.Mng qun l: Dng gim st mng bao gm c qun l mng v qun l lp.(S)y l m hnh n gin m t giao thc tng ng mng OSI chun.Lp vt l: truyn ti thng tin di dng bit v t bo.Lp ATM: x l cc t bo, ghp knh v phn knh, dng chuyn mch nh tuyn.


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Lp AAL (ATM Adaptation Layer): thc hin cc chc nng ph thuc dch v, lin ktAAL vi lp bc cao, lp bc cao thc hin chc nng ko c lp di.2/ Lp ATM v cu trc t bo:a/ Cc thnh phn ATM:ATM s dng cc knh kt ni o trong vic truyn ti thng tin v cc kt ni dc chia lm

2 mc:- Mc knh o VCL: l mc c kh nng truyn n hng cc t bo ATM tng

ng vi 1 gi tr nhn dng chung nht VCI.- Mc ng o VPL: l mc c chc nng truyn n hng thuc v nhiu knh o

khc nhau nhng li c 1 gi tr nhn dng ng o chung VPI.Trong 1 ng truyn dn c th c 1 vi ng o VP, trong VP c th c 1 vi knh oVCMi VP v VC trong ng truyn dn u c gi tr VPI v VCI ring.(S)Lin kt knh o v ng o (VC link VP link). Lin kt knh o l truyn n hngcc t bo ATM gia im m ti gi tr VCI dc gn vo t bo v ti im m cc gi

tr b thay i hoc b xo. Cn lin kt ng o l lin kt gia 2 im m gi tr VPIc gn b thay i hoc xo.Cuc ni knh o v ng o: Cuc ni knh o VCC l tp hp 1 s lin kt knh o,l 1 ng ni logic gia 2 im dng truyn cc t bo ATM thng qua VCC. Th ttruyn cc t bo ATM s dc bo ton, cn cuc ni ng o VPC l s mc ni 1 s linkt ng o VC. Mi VC dc nhn dng duy nht thng qua t hp 2 gi tr VPI v VCI.(s)a ch ni n phn cp nhn dng 2 phn ca knh ng o truy xut a ch chonhanh. Tt c cc im truy xut t ngun n ch ko cn bit. Ban u VPI l trng vn cc im chuyn mch th a ch tip theo mi dc in vo. xc nh tuyn th c

h thng ring. Qua mi trm th VPI, VCI s dc xo v thm vo a ch nh tuyn mi.b/ Cc chc nng ca lp ATM:Phn knh v hp knh cc t bo.Ti u pht cc t bo thuc v cc knh o VC v ng o VP khc nhau s dc hpknh thnh cc dng t bo duy nht. Ti u thu, dng t bo ATM dc phn thnh ccng o v knh o c lp ti thit b thu.Thng dch gi tr VPI v VCI.(s)To v tch u vo t bo: phn pht, sau khi nhn trng thng tin t lp AAL th lpATM s to ra mo u ca t bo (tr gi tr ca trng HEC s dc chn vo lp vt l).

Ti phn thu th lp ATM tch mo u ca t vo ra khi t vo v gi thng tin cho lpAAL.(s)iu khin lung chung GFC ch c giao din khch hng v mng (UNI), n gipkhch hng tham gia vo vic iu khin lu lng theo hng t khch hng v phamng.GFC dng gim bt tnh trng qu ti ca mng.c/ Cu trc ca t bo:


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Ti u thi SAR ly thng tin trong trng d liu khi phc li PDU hon chnh. Cnchc nng ca lp con hi t CS ph thuc vo dch v (x l tr, ng b, x l t bonhm mt a ch)(s)Do mi loi dch v c 1 CS khc nhau nn c th ng dng to ra mng a dch v.

Gim thiu giao thc trong AAL th ITUT chia AAL lm 4 nhm khc nhau ph thuc cim dch v ca chng, s phn nhm ph thuc 3 yu t: mi quan h v mt thi gian,tc bit v dng truyn (kiu lkt)(s)4/ Lp vt l:Dc chia lm 2 lp :a/ Lp con ng truyn vt l PM:Thc hin cc chc nng sau:

- Truyn ti bit v ng b bit- Thc hin m ng dy

- Thc hin chc nng bin i in quang (nu l cp quang)b/ Lp con hi t truyn dn TC:- To v kim tra m HEC- Nhn bit gii hn ca t bo- Bin i dng t bo thnh cc khung truyn dn- Pht v khi phc cc khung truyn dn.

5/ Cc loi t bo trong ATM:C 2 loi:a/ Cc t bo ti lp vt l:

- T bo rng th dc lp vt l xen vo hoc tch ra lung t bo ranh gii gia

lp ATM v lp vtj l c tc ph hp vi tc ng truyn.- T bo hp l l t bo ko c li hoc c 1 li n dc sa.- T bo ko hp l l t bo c nhiu li m ko sa dc.

b/ Cc t bo lp ATM:- T bo dc gn: l t bo mang thng tin dch v s dng dch v lp ATM- T bo ko dc gn l t bo ko dc SD, ko mang thng tin dch v.

Nguyn l chuyn mch v bo hiu trong ATM1/ Nguyn l chuyn mch:a/ Vic chuyn mch gia trn c s cc gi tr VCI/VPI

Thit b chuyn mch dc thc hin ch da trn gi tr VPI dc gi l chuyn mchVP, nt ni xuyn hoc b tp trung.

Thit b chuyn mch thay i c 2 gi tr VPI v VCI dc gi l chuyn mchVC, hoc chuyn mch ATM.

S gii thch nguyn l chuyn mch VP.


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Chuyn mch VP l ni bt u v kt thc cc lin kt ng o, do n cn phichuyn cc gi tr VPI u vo thnh cc gi tr VPI tng ng u ra sao cho cc linkt ng o ny thuc v cng 1 cuc ni o cho trc. Cc gi tr VCI dc gi nguyn.(s)

Nguyn l chuyn mch VC:

Chuyn mch VC l im cui ca lin kt ng o v knh o. V trong chuyn mchVC cn bao gm c chuyn mch VP Chuyn mch VC c th thc hin cc chc nngnh 1 chuyn mch VP.(s)b/ c tnh chuyn mch ATM:

- Chuyn mch gi do tnh cht tng t bo trong ATM dc truyn ti trong mng 1cch ring bit.

- Chuyn mch c kt ni do cc kt ni gi 2 u cui phi dc thit lp trc khi truynti t bo.

2/Cc loi chuyn mch:

S phn loi ca cc chuyn mch ATM:- Mng chuyn mch n tng:+ Ma trn chuyn mch m rng+ Mng chuyn mch hnh phu+ Mng chuyn mch trn- Mng chuyn mch phu tng:+ Mng chuyn mch 1 ng.+Mng chuyn mch nhiu ng.

+ Chuyn mch n tng: Cc u vo v cc u ra dc ni vi nhau bi 1 tng n ccphn t chuyn mch.

Ma trn chuyn mch m rng:(s) u im: Tr qua mng nh do mi thit b ch dc a vo m 1 ln qua mng. Nhc im: Khi s u vo tng, s phn t chuyn mch cng phi tng ln, iu

ny gii hn kch thc ca ma trn chuyn mch m rng.+ Mng chuyn mch hnh phu: pha ma trn ch nht N u vo, #b u ra. (Chuynmch ko vng, ko tc nghn) p dng vi mng chuyn mch c kch thc nh32&16, hoc 128&128+ Mng chuyn mch trn: C ch phn hi dc p dng (thit b c th dc i qua li 1 viln trong mng trn trc khi ti dc u ra cho trc)

+Nhiu tng: dc XD t vi tng ca phn t chuyn mch dc ni vi nhau theo vi tng chotrc, tu theo s ng m thit b c th i t u vo n u ra. Trong mng c th chialm 2 nhm.+Mng 1 ng: ch c 1 ng duy nht ni 1 u vo vi 1 u ra cho trc. Cc mng nycn dc gi l chuyn mch Bangan nh ng n gin. Tuy nhin c nhc im ltc nghn khi thit b yu cu ng thi u ni.


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+Mng nhiu ng: c th c nhiu lin kt dc ni u vo ti 1 u ra cho trc. V vymng c u im l lm gim, thm ch loi b tc nghn trong mng.3/ Nguyn l bo hiu:a/ Tng quan:B-ISDN s dng bo hiu ngoi bng ging nh N-ISDN.

Knh o VC l phng tin logic tch cc knh bo hiu ra khi knh ca ng sdng.b/ Bo hiu trn knh o SVC:Cc thng ip bo hiu trong ATM dc truyn qua mng trn knh o bo hiu SVC c ccloi:

- Knh bo hiu trao i: MSVC. Trn mi giao din UNI c 1 knh MSVC. MSVCl knh c nh v dc truyn theo 2 hng. L knh qun l giao din thit lp,kim tra v gii phng cc knh SVC t im ti nhiu im v cc SVC truynthng c la chn.

- Knh bo hiu t im ti im (point to point SVC): c dng thit lp, iu

khin v gii phng cc cuc ni knh o VCC ca ngi SD. N l knh bo hiu 2hng.- Knh bo hiu truyn thng (BSVC): c 2 loi, l knh n hng t mng ti

ngi SD.+ SVC truyn thng chung (general BSVC): gi thng ip cho cc im cui.+ SVC truyn thng c la chonk (selection BSVC): gi thng ip cho 1 s im cuidc nh trc (bo hiu dc gi ti tt c cc im u cui cng 1 loi dch v)

c/ Cc kiu bo hiu trong ATM:- Bo hiu ko kt hp: thc th bo hiu iu khin tt c cc knh o VC trong tt c

cc kt ni ng o VPC ti giao din ca n. Knh o bo hiu c gi tr VPCI=0

v VCI=5.(s)- Bo hiu ch kt hp: thc th bo hiu ch iu khin cc knh o VC trong 1 kt

ni ng o VCP bng cch s dng 1 VC trong VPC trao i bn tin bohiu. Bo hiu kt hp ch dc SD khi ngi SD v mng c 1 tho thun song

phng. Knh bo hiu trong trng hp ny c ch s VPI ca VPC v VCI=5.(s)

d/ Bo hiu ti giao din UNI:Trong bo hiu ti UNI, ch s nhn dng kt ni ng o VPCI dc SD thay cho VPI vVPI c th thay i khi i qua cc tb u cui cho VP.M hnh bo hiu ti UNI trong B-ISDN dc a ra bi cc khuyn ngh Q.2931 v Q.2971(S)MS: bo hiu trao i.S. AAL: Lp tng thch ATM dnh cho bo hiu.Q.2931 & Q.2971: cc giao thc lp mng giao din UNI.e/ nh dng bn tin bo hiu:Ti UNI, vc bo hiu dc tin hnh thng qua trao io bn tin bo hiu gia 2 thc th

bo hiu ngang nhau.


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(s)Phn bit cc giao thc: cc thng ip trn SVC l thng ip bo hiu hay thng ipthuc v cc giao thc khc nhau.Tham chiu cuc gi:

- Dc s dng xnh cuc gi ti giao din cc b tng ng vi thng tin ang

truyn.- Gi tr tham chim cuc gi dc gn bi pha gc cuc gi, l duy nht v tn ti

trong sut thi gian cuc gi .- Khi cuc gi dc gii phng, gi tr ny dc gii phng. Hon ton c kh nng 2 cuc

gi c cng gi tr tham chiu cuc gi trn cng 1 SVC khi 2 cuc gi xut pht t2 pha. Xut pht gn c F=0, bn tin tc t pha nhn gn cho c gi tr 1.

Trng kiu thng ip (bn tin): xc nh chc nng bn tin ang dc gi. Cc thng ipring cho quc gia, bn tin thit lp cuc gi, gii phng cuc gi, xo cuc giTrng di bn tin: di = 2 byte khai bo di ca ni dung thng ip.Thnh phn thng tin c di thay i: Mi bn tin c cc thnh phn thng tin ring,

mang ni dung c trng cho bn tin. S c mt ca thnh phn thng tin ny c th l tuchn hay bt buc, ph thuc vo ni dung ca bn tin.

Phn IV: Mng th h k tip NGN v chuyn mch phn mmTng quan NGN

1/ n NGN:NGN l mng c c s h tng thng tin duy nht v da trn cng ngh chuyn mch gi.Trin khai dch v 1 cch a dng nhanh chng, p ng s hi t gia thoi v d liu,gia c nh v di ng.

Tn gi ca NGN: + Mng a dch v+ Mng hi t+ Mng phn lp

NGN ko l loi mng mi m l s pht trin c s k tha v s dng cc h tng sn c a ra cc dch v ti u cho ngi SD, a ra kin ti u s dng h tng.2/ c im:

- Cu trc phn lp theo chc nng v phn tn cc tim nng trn mng, s dngrng ricc giao din m API lm cho cc dch v ko ph thuc nhiu vo nh cungcp thit b.

- D dng pht trin mng, cho php chuyn giao dch v v cng ngh khi c yucu ny sinh.

- C s tch bit gia kt ni v iu khin cuc gi hay dch v.- Lp iu khin dch v c lp vi lp cng ngh s dng trong mng.

3/ Cu trc mng NGN:Lp NGN:

- Lp truy nhp- Lp truyn ti- Lp iu khin


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- Lp ng dng & dv- Lp qun l

(s)

Cu trc mng NGN1/ Lp truy nhp: Chc nng: cung cp kt ni gia thit b u cui v mng ng trc (ph thuc

lp truyn ti) qua cng giao tip thch hp.+ Cng MG (media gateway)+ Tb u cui (thu bao ca mng NGN) in thoi POTS (thoi thng thng), IP,ISDN, di ng, tng i PBX, VoIP hoc VoDSL.

Thnh phn:Cc thit b truy nhp cung cp cc cng kt ni thu bao qua h thng mng ngoi vi (cpng, cp quang hay v tuyn)

Cng truy nhp: VoIP, FR, ATM, DSL.Chuyn i cc phng tin truy nhp khc nhau vo mng ng trc, trao i cc thngtin v tuyn: GSM, CDMA, WLL.Hu tuyn: Cp ng x DSLCp quang SDHWDM

PON2/ Lp truyn ti:

Thnh phn:- Cc nt chuyn mch, cc b nh tuyn v cc thit b truyn dn.- N hot ng di s iu khin ca chuyn mch mm v chuyn mch cng

trong lp nh tuyn tn hiu dc chuyn mch v nh tuyn. Lp li (core):- Truyn dn: SHD, WDM- Chuyn mch: ATM/IP, MPLS

Cc chuyn mch dc trang b cng ngh ATM/IP v mng chuyn mch gm 2 lp:+ c/m lp li: dng x l cc cuc gi lin vng v quc t.+ c/m lp bin: mc ch gim chuyn mch ni ht v thay th bng tng ichuyn mch a dch v.

MPLS: l s kt hp ca ATM v IP s dng c ch hon i nhn nh trong ATM tng tc truyn gi tin m ko cn thay i giao thc nh tuyn ca IP.Chuyn mch quang: da trn nguyn tc chuyn mch quang phn chia theo thi gian,kgian, hay bc sng.

Truyn dn: cc lp vt l ang dc trin khai s dng truyn daaxn quang vi kthut ghp knh bc sng quang.

- Lp 1: lp vt l- Lp 2 v 3: chuyn mch gi, km theo c cht kim sot QoS tip tc s dng

truyn dn SDH, hon thin v nng cp cc h thng truyn dn.


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- Xu hng tin ti XD 1 mng truyn ti OTN, mang dc tt c lu lng ATM/IPtrong mng.

3/ Lp iu khin: Thnh phn:- Thnh phn chnh ca lp iu khin l chuyn mch mm. Chuyn mch mm c

chc nng: kt ni vi cc thnh phn khc kt ni cuc gi hay qun l a chIP.

- B iu khin cng truyn thong MGC- Tc nhn cuc gi Chc nng:- iu khin kt ni cuc gi thng qua vic iu khin cc thit b chuyn mch v

iu khin cc thit b truy nhp.- Lp iu khin dc t chc vo 1 cp cho ton mng- Chc nng iu khin dc phn b theo vng lu lng.- Lp diu khin lin kt u cui vi lp ng dng v dv cho nn n cng thc hin

chc nng qun l chm sc khch hng, tnh cc.- Ngoi ra lp khin cn c chc nng nh 1 HT cng gateway nhm qun l kt

ni, qun l mg, khai bo vo qun l dch v.4/ ng dng v dch v:

- Chc nng cung cp dch v n ngi SD 1 cch thng nht v ng b- Dc t chc tnh 1 cp trong ton mng.- Lp ng dng v dch v lin kt vi lp iu khin thng qua giao din m API.- Cung cp dch v c bng thng khc nhau v kiu dch v khc nhau, 1 s dch v

truy nhp trc tip ti lp ng dng, 1 s khc iu khin t lp iu khin nh dchv thoi truyn thng.

5/ Lp qun l:L lp xuyn sut cc lp pha trn, thc hin 3 chc nng chnh: qun l mng, qun ldch v v qun l kinh doanh.

Chuyn mch mm trong NGN1/ S ra i ca soft switch:

- NGN tch chc nng x l cuc gi ra khi thit b chuyn mch vt l v kt ni 2thnh phn ny vi nhau thng qua 1 giao thc chun.

+ Phn chuyn mch vt l gi l MG (media gateway)+ Phn x l cuc gi l gi l chuyn mch mm, MGC, Call agent.

- Nguyn nhn cho thy vic phn tch:+ Cho php c 1 gii phng phn mm chung cho x l trn nhiu mng khc nhau, baogm c chuyn mch knh v chuyn mch gi.+ L ng lc cho cc HT iu hnh v cc mi trng my tnh chun, tit kim trongvic pht trin cc phn mm x l cuc gi.+ To c hi cho cc cng ty nh tham gia vo th trng. Gim bt s c quyn.

2/ So snh gia chuyn mch knh v chuyn mch mm:


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Cu trc chuyn mch:- Trong chuyn mch mm, m hnh hot ng theo cc module ring bit. Phn mm

iu khin x l cuc gi ko ph thuc phn cng chuyn mch vt l cng nh mitrng truyn thng tin.

- Trong chuyn mch knh, tng i l 1 khi thng nht, thc hin tt c cc cng

vic: s ho tn hiu, thc hin chuyn mch v ghp knh.(s) c tnh chuyn mch:- Chuyn mch mm c th thc hin tt c cc chc nng ca tng i in t, hn

na c th tch hp c chc nng ca tng i ni ht hoc chuyn tip, hoc chcnng ca tng i doanh nghip.

- Chuyn mch mm cho php lin kt IP & PSTN truyn thng iu khin v chuynmch lu lng hn hp gia thoi, d liu v video.

- Phng thc chuyn mch: Trong chuyn mch mm thc hin da trn phn mm.Thit b chuyn mch mm thc hin chuyn mch gia cc knh o, trong mi

knh o tng ng vi 1 knh mng. Cc knh mng thoi th ko i qua chuynmch mm m ch i qua cc cng kt ni MG ri vo mng gi. Khi chuyn mchmm thc hin chuyn mch gia 2 knh o th n s bo cho cc MG qua giao thcMGCP ch ra nh tuyn cho cc knh mng.Vi chuyn mch knh th knh thoi dc nh tuyn v chuyn mch tng i.

(s)- Bo hiu:+ Trong chuyn mch mm: Thoi v bo hiu l 2 knh ring bit, truyn ti qua 2knh kt ni khc nhau, vi tn hiu bo hiu dc truyn qua signalling gateway. T/hthoi truyn qua MG.

+ Trong chuyn mch knh: Thoi v bo hiu cng l 2 knh khc nhau nhng cngtruyn n 1 im x l trn ng dy hay trn cng 1 kt ni vt l.- S lin kt phn cng:+ C/m knh: khi thng nht, phn mm iu khin lin kt cht ch.+ C/m mm: tch bit. Phn mm tch ring khi phn cng c th d dng thay i

phn mm.- Dch v:+ C/m knh: ch yu l thoi, fax.+ C/m mm: ngoi thoi, fax cn c audio- Gi thnh:

+ C/m knh: gi thnh trin khai l t.+ C/m mm: gi thnh gim, ch tp trung cho chi ph phn mm.- Kh nng a dv:+ C/m mm: D dng a ra cc dch v mi, c tnh m.+ C/m knh: ko c tnh m. c quyn.

3/ Cc giao thc trong mng NGN:- H_323


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- SIP (khi to phin)- MGCP- Megaco /H248(s)

Chuyn mch nhn a giao thc MPLS1.MPLS truyn dl theo cc ng LSP(label Switched Path)Cc ung LSP cha dy cc nhn ti tt c cc nt dc theo tuyn t ngun n ch.Ccnhn c phn phi.- Nhn c phn phi:Cc giao thc phn phi nhn LDP or cc giao thc RSVP cng gi li v mang cc nhn trong thi gian i t S n D.(s)-u im :

+ K thut lu lng TE-CoS & QoS c kh nng thit lp ng truyn lu lng,thitlp cho cc lp dch v v xc nh dch v,,

+ Cung cp IP da vo mng ring o VPN c th ra ng hm IP trn MPLS.Do khng cn m ha d liu u cui.

+ Loi b cu hnh a lp:thng thng sd m hnh chng ln.ATM sd lp 2IP sd lp 3

Vi vic sd MPLS cn iu chnh cc khi chc nng ca mt phng iu khinATMvo lp 3.Do s lm ng ha mng v qun l mng.

+ Tuyn hin: Cc ng chuyn mch nhn c nh tuyn sn,cc ng nh tuynny hiu qu hn so vi ty chn tuyn ngun trong IP.

+ H tr a lien kt v a giao thc.

Frame mode : do truyn dn frame relayCell mode : ATM-Nhc im:

+ H tr a giao thc > phc tp trong kt ni+ Kh thc hin h tr QoS xuyn sut+ Vic hp nht cc knh o vn cn ang c xem xt+ Vic chn cc tb > vic chim nhiu ti nguyn trong b m.

2,3,4.Cc thnh phn MPLS* Nhn MPLS :

C di ngn v c nh c gn vo gi tin c th.Dng ca nhn ph thuc phng

tin truyn m gi tin c gn nhn.Nhn c th l trng VCI & VPN & cng c th ltrng nhn.i vi cc phng tin gc trong c cu trc nhn 1 trm m 32 bit s c chn them

sd cho nhn.(s)

+ Trng nhn 20 bit th hin gi tr ca nhn,dung gn cho cc gi tin ,trao icho cc b nh tuyn.

+ Trng EXP cn c tn gi lp dch v CoS,c th tc ng n tt c hng i.


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+ Ngn sp S c 1 bit h tr s phn cp nhn trong ngn xp nhn thng mi khi iqua 1 b nh tuyn th gi tr TTL gim i 1.Khi TTL quay tr v 0 th gi tin s b loi

b.* Ngn xp nhn :

+ Ngn xp nhn xut hin sau tiu ca lp IP ng trc mi tiu ca lp mng,+ Gi d liu ca lp mng i theo cng vo chng nhn m c bit S c thit lp.+ Trong 1 frame lien kt d liu ,th ngn xp nhn xut hin trong tiu IP v tiu lin kt d liu,+ i vi truyn dn ATM,cc tb ATM gi tr nhn trong ngn xp nhn cao nht c tvo trng VCI & VPN,ph thuc tiu .Gi tr nhn u tin khng duy tr ti phn uca ngn xp nhn m c chn vo trong tiu thng bo v tiu IP.* ng chuyn mch nhn LSP :

L ng nm trong cc b nh tuyn chuyn mch nhn LSR.LSR li vo v ccLSR li ra.

(s)- Phng thc thit lp LSP:+ nh tuyn theo tng chng : Mi LSR la chn ring 1 FEC xc nh.+ nh tuyn hin : LSR li vo ch nh cc nt m LSP i s i qua.

- Thuc tnh LSP : C td khi tnh ton or thit lp,+ Bng thng ; yu cu bng thng c th dnh c ti thiu l 1 ng ph thucLSP.+ Ph thuc tnh ng : N xc nh LSP c xc nh th cng or c tnh tonng t cc thut ton nh tuyn rng buc,u tin thit lp.+ Ph thuc tnh u tin chim d : l phn ti nguyn LSP ang chim gi.

+ Ph thuc tnh n hi: n x nh tuyn li LSP khi ng hin ta b sa haykhng.+ Ph thuc tnh thch nghi : xem xt chuyn LSP sang 1 ng khc ti u hn haykhng khi ng ny sn sang,

*B nh tuyn chuyn mch nhn LSR : LSR thc hin chc nng chuyn tip gi tintrong phm vi mng MPLS bng th tc phn phi nhn.

- LSR-bin(LER) : label Edge Router ,nm bn trong mng MPLS.+ chc nng : Gn hay loi b cc nhn cho c gi tin > or i ki MPLS.+ Cc LER c th l cc LER li vo : Ingress LER

ra : egress LER- LSR li :

- Chc nng : chuyn tip cc gi c nhnATM-LSR da cc execel mode

+ ATM-LSR li :Chc nng :s dng giao thc ca MPLS thit lp knh o ATM v chuyn

t bo ATM n ATM-LSR tip theo.+ ATM-LSR bin :


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Chc nng : Nhn gi tin c nhn hoc o c nhn v n chia ra thnh cc t boATM v gi cc t bo ATM-LSR k tip.

u ra : nhn cc t bo ATM ti to cc gi v chuyn tip gi c nhn orkhng c nhn.3.Lp chuyn tip tng ng FEC

L s phn loi ca cc gi c chung thuc tnh nh : cng a ch ch,cng yu cu vdch v nh lung muticast,QoS

FEC c gn cho gi ti LSR li vo(LER).LER phn loi gi n v lin kt chngti cc FEC.Mi 1 FEC kt hp vi 1 nhn thch hp v 1 ng chuyn gi.

Chng nhn > Khi 1 gi tin c gn nhiu nhn>ch ra s phn cp ca mng.4.Bng thng tin nhn LIB (Label Information Base)+ Mi 1 FEC yu cu 1 nhn ring bit.LER li vo s lit k cc FEC vi cc nhntng ng vo 1 bng gi l c s thng tin nhn LIB.+ LIB bao gm thng tin v nhn u vo ,nhn u ra giao din u ra c bc nhy tiptheo.

IP ch Cng FEC Nhnvo Nhnra Cngra Bcnhytiptheo

Hotng

192.41.21.210

80 1 __ 55 2 213.32.8.27

Gn

157.52.63.3 80 16 22 60 15 20.38.73.19

Honi

171.41.21.210

80 3 71 25 20 191.1.2.160

Honi

124.23.87.3 80 12 95 __ 22 185.53.43.9 Tch

5.Hot ng ca MPLS* MPLS l cng ngh kt ni nh hng.ng vi mi lp chuyn tip tng ng FECl cc c tnh lu lng xc nh yu cu,dch v cho lung .Cc b nh tuyn LSR khng kim tra v x l cc tiu IP m ch chuyn tip cc gida vo gi tr nhn.*LER li vo :

Nhim v : Phn loi gi ph thuc FEC bit hoc khng.Nu m gi tng ng 1 giFEC bit th LER s gn nhn cho gi v chuyn n LSR k tip.LSR xc nh y l 1

FEC mi>n s kt hp vi LSR khc v s dng giao thc phn phi nhn thit lpLSP tng ng vi FEC mi .(s)* LSR li :

Nhim v : Khi 1 LSR nhn c 1 gi c gn nhn th n s xa nhn li vo vgn 1 nhn li ra v s chuyn tip gi ti LSR k tip.* RER li ra :


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Nhim v : Tch nhn ,c tiu IP xc nh a ch IP ch v chuyn tip gi t chtip theo.

Bo hiu H2321.Khi qut v H232:- H232 l nhm tchun kthut cho truyn dn video, audio v d liu thng qua gthcmng internet IP do ITU a ra.- H232 gm c chc nng bhiu v khin cuc gi giao vn v iu khin truyn thng,khin rng bng tn cho hi ngh t im ti im hoc a im.(hv)2.Cu trc H232:- Thnh fn chnh:+ u cui (terminal H232)+ Gateway: chuyn i gthc 1 u cui khng fi H232 c th lin lc vi 1 u cuiH232.

+ Gatekeeper+ MCU (multipoint control Unit): v khin a imthit lp cc hi ngh.(s)*Terminal H232:- L 1 in thoi hay l 1 my tnh chy ng dng H232. c dng cho truyn thg 1 chiuthi gian thc. Dng cho c t/h audio, video v d liu.- Bao gm:+ M ha v gii m Audio.+ M ha v gii m video.+ B m: khi nhn t/h audio, video vo b m sp xp li khi truyn t/h ra c cng 1

tc .+ Hthg iu khin: thit lp cc cuc gi s dng cc knh khin # fa # ca cuc gi.

thit lp cuc gi dng H2250RAS: trao i thng tin gia Terminal H232 vi Gateway Keeper.H245.

*Gateway:- Chc nng: thng dch gia mng IP v mng thoi: c vai tr cu ni v ch tham giavo 1 cuc gi khi c s chuyn tip t mng H232 sang mng phi H232.- Chuyn i gia cc dng khung truyn dn.VD: t H225 sang H221.- Chuyn i gia cc dng m ha # ca lung t/h.

- T/hin vic thit lp v gii fng cuc gi c 2 fa.*Gatekeeper:- L fn t k nht thit fi c trong H232. N thc hin chc nng khin dv cuc gigia cc im u cui H232.- Chc nng chnh phn ra 2 loi:+ Chc nng bt buc:

Dch a chkhin truy nhp.


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Thc th ng dng chnh l cc t/b u cui. N c th l 1 thoi SIP hoc 1 my tnhchy phn mm SIP.Cc thc th li gm thnh fn sau:+ UAC( User Agent Client): dng khi to cc yu cu.+ UAS( User Agent Server): dng nhn cc yu cu v tr li li cc yu cu)

*Server mng (Network Server):C 1 s server mang khc:- Proxy server: l 1 phn mm trung gian hot ng nh c server v client t/hin ccy/c thay mt cc u cui khc. Cc proxy server s x l cc y/c nu c th. Nu k n st/hin cng vic chuyn i hoc dch sang cc khun dng thch hp v chuyn cho ccserver khc.- Server v tr( location server): nh v thu bao, cung cp tt v nhng v tr ca fa bgi cho proxy server v cc server chuyn tip.- Server chuyn tip (Redirect server): c n/v nhn cc y/c ca SIP v chuyn i cc ich SIP sang 1 s a ch khc v i li cho u cui. C th cc server chuyn tip nhn

cc y/c n xnh a ch ca server chng tip theo v gi cho client cho client gi thngy/c n server ch.Ch : Server chuyn tip khng hot ng nh 1 u cui( k gi i bt k 1 y/c no, knhn v hy cui gi)- Server ng k( Registration server) c nv nhn cc y/c ng k. N m nhim 1 schc nng an ninh nh xnhn ng s dng. Thng thng n hot ng cng vi proxy hocserver chuyn tip cung cp dv nh v thu bao.(hv)3. Hot ng ca SIP:*a ch SIP:

- Cc SIP c nhn dng qua a ch ti nguyn ton cu (URL)- Cu trc a ch ny l: User@host.+ Phn user: tn ng sdng hay s thoi.+ Phn host: c th l a ch mng hay l tn min.VD: SIP: [email protected]: [email protected]*Thit lp cuc gi: c 2 kiu:- Kiu proxy server: Ch hot ng kiu proxy server:(s)- Kiu Redirect server:(s)

Giao thc MGCP (Media Gateway Control Protocol)Megaco/H.248

SGCP (Simple Gateway Control Protocol) ra i do: Gii quyt vn t_ng thch bo hiu gia mng PSTN v cc mng da trn cng nghIP (IPbased)
mailto:[email protected]:[email protected]:[email protected]:[email protected]


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Hiu qu thp, chi ph cao. VD: chuyn i bn tin bo hiu SS7 s gy mt thng tin MGCP l phin bn mi ca SGCP:

L giao thc iu khin cc gateway thoi thng qua MGC (Media Gateway Controller)hoc CA (Call Agent)- Tch bit cc chc nng bo hiu v thit lp ng truyn

H.323 v MGCPH.323 Gateway phn tch yu cu gi v nh tuyn. MGC m nhim chc nng nh tuyn cho ngi dng.Tng thch ti a. Giao thc iu khin cng c lp, thch ng vi nhiu giao din: trungk PSTN, ATM, thoi IP, Server... n gin v mm do. Dc SD trong NGN nh giao thc k tip MGCP. S dng m hnh Master/Slave. MGC iu khin kt ni, iu khin cu hnh thit b quaMegaco/H.248 Tnh m cao. c pht trin bi IETF v ITU

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