Mang Tich Hop Da Dich Vu X-Isdn

8/14/2019 Mang Tich Hop Da Dich Vu X-Isdn

1/73

10/1/2007 1

H THNG VIN THNG VI CNG NGHMI

CHNG 3 :

MNG TCH HP SA DCH V BNGRNG B-ISDN

INH TH THI MAIReference: Broadband Communications Technology


2/73

0/ / 00

10/1/2007 2

CHNG 3: MNG TCH HP SA DCH VBNG RNG B-ISDN

CHNG 3: MNG TCH HP SA DCH VBNG RNG B-ISDN

PHN 1: GII THIU TNG QUAN VB-ISDN V ATM

PHN 2 : M HNH THAM CHIU GIAOTHC MNG B-ISDN


3/73

10/1/2007 3

PHN 1: GII THIU TNG QUAN V B-ISDN V ATMPHN 1: GII THIU TNG QUAN V B-ISDN V ATM

1.1 Khi qut v B-ISDN1.2 Kin trc mng B-ISDN

1.3 Cng ngh ATM v cc c trngcbn


4/73

10/1/2007 4

PHN 2 : M HNH THAM CHIU GIAO THCMNG B-ISDN


2.1 M hnh tham chiu giao thc B-ISDN

2.2 Lp vt l ca B-ISDN

2.3 Lp ATM ca B-ISDN

2.4 Lp thch ng ca B-ISDN2.5 Cc lpca o ca B-ISDN


5/73

10/1/2007 5

PHN 1: GII THIU TNG QUAN V B-ISDN VATM


1.1 Khi qut v B-ISDN

1.2 Kin trc mng B-ISDN

1.3 Cng ngh ATM v cc c trng

cbn


6/73

10/1/2007 6

1.1 Khi qut v B-ISDN1.1 Khi qut v B-ISDN

Mng bng rng

- Mng bng rng lmng cung cp cccdchv tho mn nhu cu ca khch hng. l mng ckh nng truyn ti nhiu loi hnh dch v, t cc

dch v vin thng truyn thng nh in thoi, fax n cc loi hnh dch v cao cp hn nh truynhnh s, HDTV, in thoi Video, truyn d liu tc

cao, VOD, Multimedia, Internet, Telephony

-Ccdch vbng rng c thc hin trn cs

cc cng ngh Frame Relay, SMDS (SwitchedMultimegabit Data Service) v cng ngh ATM


7/73

10/1/2007 7


Cc loi dch v (theo tiu chun ca CCITT )

- Bng hp ( Narrowband ): cc dch v c tc 64 Kbps.- Bng trung ( Wideband ): cc dch v c tc 64Kbps n 1.5 Mbps ( T1, E1 ).- Bng rng ( Broadband ): > 1.5 Mbps ( T1, E1 ).Trong dch v thuc nhm 1 v 2 l N ISDN.Dch v thuc nhm 3 l B ISDN.


8/73

10/1/2007 8


nh ngha B-ISDN

- B-ISDN l mt dch v yu cu knh truyn dnc kh nng h trtc ln hn tc cbn

- iu c ngha l B - ISDN s dng bngthng rt ln p ng cc yu cu ng dng vdch v cao cp. y, chng ta s cp ti cc

kha cnh k thut v cng ngh B-ISDN v ATM


9/73

10/1/2007 9


ng lc pht trin B-ISDN

ng lc caB-ISDN

Cng ngh ng dng

Doanh nghipTiu chun


10/73

10/1/2007 10


ng lc pht trin B-ISDNCng ngh

Nhng cng ngh thc y B ISDN pht trinmnh m gm:

- Cng nghbn dn vi mch v quang t

- Cng ngh quang si

- Cng ngh Vi x l v my tnh s


11/73

10/1/2007 11


ng lc pht trin B-ISDNng dng

Nhu cu ng dng cc dch v B-ISDN vo cucsng v cc hot ng ca khch hng l mt trongnhng ngun ng lc quan trng.

- Lin k t mng LAN

- X l nh/Video

- nh ho

- Siu my tnh

- Multimedia


12/73

10/1/2007 12


ng lc pht trin B-ISDNDoanh nghip

- Vi nn kinh t ton cu ho hin nay, cc tp onv cng ty mnh pht trin trn th trng, h lun

n lc tm kim th trng mi v iu khin i tcvi y u cu cung cp dch v mi cht lng cao =>Kch thch, thc y vic to r a c c lnh vc cngnghip mi.


13/7310/1/2007 13


ng lc pht trin B-ISDNTiu chun ho

- Tiu chun ho c vai tr r t quan trng m bothnh cng cho cng ngh.

- To ra cc giao thc, cc ch tiu k thut sao chobt k nh u t no cng c thpht trin snphm s dng c trong mt mng ton cu thng

nht.


14/7310/1/2007 14


Nn tng ca B-ISDN


15/7310/1/2007 15






cbn


16/7310/1/2007 16

1.2 Kin trc mng B-ISDN1.2 Kin trc mng B-ISDN

Hnh: Cu trc quan im ca B - ISDN

ATM(XC)

ATM(SW)

ATM(SW)

BISDN - NT BISDN - NT

BISDN-TE BISDN-TE PBX LAN/MAN


17/7310/1/2007 17

1.2 Kin trc mng B-ISDN1.2 Kin trc mng B-ISDN

Hnh: Cu hnh chun ca B - ISDN

B-NT1ATMSW

LAN/MAN

IWU

ATMSW

ATMSW

B-NT1 PBX

PSTN

PSDN

B-NT2B-TE1

B-TAB-TE2

Pha mng

NNI

UNI(Un)

UNI(Un)

TbSb

R

Pha ngi dng


18/73


19/7310/1/2007 19

1.2 Kin trc mng B-ISDN1.2 Kin trc mng B-ISDNCu hnh chun ca B ISDN pha UNI

Cc khi chc nng

- NT1 kt cui mng loi 1 thc hin chc nng lp 1ca m hnh OSI. Chc nng ca NT1 bao gm truyndn trn ng dy tn hiu s, cp ngun DC, nh thi

v ngoi ra NT1 cng thc hin chc nng bo dng sb.- NT2 l k t cui mng loi 2, NT2 l kt cui mng

thng minh ( v d nh PABX ) tng ng vi mc 1 vmc mng cao hn ca m hnh OSI. N thc hin chcnng thch ng mi trng ghp knh, tp trung lulng. Trn thc tNT1 vNT2 c th kt hp vo mtthit b chung ch c mt trong hai kiu tu thuc vothuc tnh thu bao c th.


20/7310/1/2007 20


Cc khi chc nng

- TE1: Thit b u cui loi 1 thc hin chc nngtng tc vi lp 1 v lp cao hn, chc nng ca TE1

bao gm cc giao din user to user, user to machine v

cc giao thc qun l bo hiu, qun l OA& M v iukhin trao i thng tin cho user. TE1 x l v thc hincc chc nng c chun h o bi giao din chun cho

mng B-ISDN theo khuyn ngh ca CCITT.- TE2: Thit bu cui loi 2. Chc nng tng ngnh TE1 ch c iu khc l khng tun theo giao dinchun ca CCITT.- TA: B thch ng u cui ( Terminal Adapter ) c vaitr thch ng cho TE2 vi mng B - ISDN.


21/7310/1/2007 21


Cc im chun

- Cc im chun Sb v Tb cung cp phng tintin ch xc nh cc thuc tnh vt l in kh dctheo tuyn truyn tin. C th l giao din lp vt l

ti cc im chun ny c th chn hay l cho ccphng thc truyn tin theo SDH-Based hoc Cell-based.- im chun Tb - giao din n dng cho B -

NT1 v mi trng vt l phc v cho kiu kt niim - im.


22/7310/1/2007 22


Cc im chun

- im chun Sb: c th c nhiu giao din dngcho B-NT2 v n cung cp kiu kt ni im - ti

im lp vt l v k t ni im - a im lpcao hn- im chun R: nh ngha giao din kt ni TE2

vi mng thc hin nhim v thch hp tc btcho TE2 c th


23/7310/1/2007 23






cbn


24/7310/1/2007 24

1.3 Cng ngh ATM v cc c trng c bn1.3 Cng ngh ATM v cc c trng c bn

Cng ngh ATM v ng dng trong B-ISDN

Tbo ATM


25/7310/1/2007 25

Cng ngh ATM v ng dngtrong B-ISDN


ATM : Asynchronous Transfer Mode Phngphp truyn dn khng ng b (ghp knh v

chuyn mch) ATM : l mt kiu chuyn mch gi vi cc gi

c kch thc c nh (53 byte) hay cn gi l tbo (tbo ATM)

Phng thc: Hng kt ni (connection

oriented) S dng ghp knh khng ng b (thng k) gi

l ATDM (Asynchronous Time DivisionMultiplexing)

C h ATM dC h ATM d


26/7310/1/2007 26



Ghp knh ATDM v TDM

TDM

.A .B.C

1 2 3

1 2 3

ATDM

A

BC

1 2 3

1 2 3

C h ATM dC h ATM d


27/7310/1/2007 27



Ghp knh TDM

- Nguyn l: gn knh c nh cho cc khe thigian m khng quan tm n c thng tin hay khng

- Nhc im: Lng ph ti nguyn ng truyn

Tc khng thay i

C h ATM dC h ATM d


28/7310/1/2007 28



Ghp knh ATDM

- Nguyn l: Lu tr cc tn hiu tc thp vomt b m, sau khi phc li v chn cc tnhiu c lu tr vo cc khe thi gian theo nguyn

l lp lch u tin (V d: FIFO). y, cc tn hiuvo l cc tbo ATM

- u im:

Tit kim ti nguyn

Tc ca cc knh l khc nhau v c th thay

i


29/7310/1/2007 29

ng ng v ng ngtrong B-ISDN


Cng ngh ATM - Sla chn cho B-ISDN

K thut hin thi.

Yu cu i vi B -ISDN

CM knh CM gi Truyn dnSTM

Giao din UNI tc cao Tt Km Tt

Cc dch v VBRv UBR

Km Tt Km

Hiu qu sdngti nguyn Km Tt Km

Nhu cu mi spht sinh trong

tng lai

? ? ?


30/7310/1/2007 30



Cng ngh ATM - Sla chn cho B-ISDNATM & B - ISDN.

Kin trc mng ng nht.Tc bt thay i ( bng rng v VBR ).Hiu sut s dng ti nguyn cao.

Gi thnh r v bo v u t.

Dch v a phng tin ( Multimedia Services ).

Yu cu ca khch hng Cng ngh

Lu lng kiu dng v t binCht lng truyn dn v QOScao

Dch vphong ph

Gi thnh r, tin s dng.Ton cu ho.

1. IC LSI &VLSI.2. X l s ( SPC v mytnh )

3. Cp si quang.


31/7310/1/2007 31



Cng ngh ATM - Sla chn cho B-ISDN

Cc tnh nng u vit ca cng ngh ATM:

Tnh linh hot: D p ng mi dch v mi trong tnglai. S dng ngun ti nguyn hiu qu cao: Phi hp mng

mi ( ATM ) vi mng c ( PDH/SDH ) tt. N l mt mng vn nng n gin ( th tc x l tbort n gin)

Gim gi thnh OA & M ( Operation Adminstration &Maintenance ). Gim gi thnh truyn dn.

m bo cp knh bng rn g v r t nng ng, mmdo. Tc truy cp mng cao.


32/73

10/1/2007 32

1.3 Cng ngh ATM v cc c trng c bn1.3 Cng ngh ATM v cc c trng c bn

Cng ngh ATM v ng dng trong B-ISDN

Tbo ATM


33/73

10/1/2007 33

T bo ATMT bo ATMCu trc t bo ATM

Header Space

User informationSpace

bit # 8 7 6 5 4 3 2 1 Octect #1234567

53


34/73

10/1/2007 34


Tiu ch chn la kch thc

- Hiu qu truyn dn:

T l H/L cng nh cng tt => hiu sut truyn dncao => Gim kch thc tbo tng hiu sut

truyn dn.- tr: cc loi hnh dch v yu cu tnh thi gianthc cao. Kch thc tbo cng ln => tr cng

ln => Gim kch thc tbo gim tr truyntin

1/( ) (1 / ) L L H H L= + = +


35/73

10/1/2007 35


Tiu ch chn la kch thc

- Tn tht: Gi cng ln xc sut tn tht cng caov cht lng dch v QoS cng km.

- n gin ho phn tiu => cc gi bng nhau(khng cn phn ch di gi).


36/73

10/1/2007 36

T bo ATMT bo ATM

Cu trc Header ca t bo ATM

GFC VPI

VPI VCI

VCI

VCI PT CLP

HEC HEC

CLPPTVCI

VCI

VCIVPI

VPI

Cu trc Header ti giaodin UNI

Cu trc Header ti giaodin NNI


37/73

10/1/2007 37

T bo ATMT bo ATM

Cu trc Header ca t bo ATM

- GFC (Generic Flow Control): iu khin lung- VPI (Virtual Path Indentifier): Tn ng o

- VCI (Virtual Channel Indentifier): Tn knh o- PT (Payload Type): Kiu trng tin

- CLP (Cell Loss Priority): u tin tn tht tbo

- HEC (Header Error Control): iu khin s a i li tiu


38/73

10/1/2007 38

T bo ATMT bo ATM

Cu trc Header ca t bo ATM - GFC

- Chim 4 bit- Ch c giao din UNI

- H tr iu khin lung lu lng t ngi dngvo mng

- H trchia s ti nguyn gia cc u cui ATMtrong mng khch hng


39/73

10/1/2007 39

T bo ATMT bo ATM

Cu trc Header ca t bo ATMVPI/VCI

- i vi UNI gm 24 bit: 8 bit VPI v 16 bit VCI.- i vi NNI gm 28 bit: 12 bit VPI v 16 bit VCI.

- VCI : c s dng thit lp cc cuc ni s dng bng bin dch Node chuyn mch ATM

- VPI : thit lp ni mt ng ochomt hay nhiu

VCIs tng ng trong hng v cc c trng dch v.

- Nu chuyn mch ch da trn gi tr VPI th c gi l

kt ni ng o, nu da trn c hai gi tr VPI/ VCI thc gi l k t ni knh o.


40/73

10/1/2007 40

T bo ATMT bo ATM

Cu trc Header ca t bo ATMVP/VC

Hnh : Khi nim v ngo v knh o trong lp vt l.


41/73

10/1/2007 41

T bo ATMT bo ATM


- Knh o (VC) ch tn ti vt l khi cn thit ngha lch tn ti trong thi gian thc s truyn ti tbo ATM.Knh vt l ng vai tr nh mt ng khng l chung

cho mi ngun truyn tin.- Trong tng tbo knh o c nhn dng bi gi tr VCI. Ti cc nt chuyn mch bng nh tuyn s cung

cp cc thng tin thng dch VCI cho tng t bo khic truyn ti. Thng tin cn thit ca bng ny ccp nht trong giai on thit lp cuc gi v g i nguyngi tr ny trong sut qu trnh cuc gi. Mi VCI s cmt gi tr ring v cc lin kt VCI khc nhau c gi trkhc nhau.


42/73

10/1/2007 42

T bo ATMT bo ATM


- ng o: l mt tp hp cc lin k t o c chungim kt cui. Chui cc lin kt o lin k t vi nhau tothnh mt kt ni ng o ( VPC ), ni gia hai im

kt ni VPC hoc xt trong cu hnh im a im c skt ni t hai trln.- ng truyn o c phn bit bi gi tr nhn dng

ng o VPI. Cc bn thng dch tuyn cc ntchuyn mch s thc hin s thng dch gi tr VPI catng t bo khi thm nhp vo cc b ni cho. Ccthng tin i vi cc knh o thuc ng o ny khng

b x l, tt c knh o thuc ng o s c truynti trn cng mt ng o.


43/73

10/1/2007 43

T bo ATMT bo ATM

Cu trc Header ca t bo ATMTrng ti thng tin PL

- Gm 3 bt- Dng ch th thng tin c truyn ti l thng

tin khch hng hay thng tin mng, khi PT mang ccthng tin mng ( nhng c xy ra tc nghn ) mngs c x l i vi trng thng tin ca tbo.

A


44/73

10/1/2007 44

T bo ATMT bo ATM

Cu trc Header ca t bo ATMTrng u tin tn tht t bo CLP

- Ch c mt bt.- Gi tr ca bt ny c th c xc lp bi khch

hng hoc nh cung cp dch v, dng cho mc chiu khin tc nghn.- Cc t bo c CLP=0 c mc u tin cao v

CLP=1 c mc u tin thp hn. Vi tbo c CLP=1 sb o thi nu trong mng xy r a tc nghn.

T b ATM


45/73

10/1/2007 45

T bo ATMT bo ATM

Cu trc Header ca t bo ATMTrng iu khin li tiu HEC

- Trng ny gm 8 bit, c x l lp vt l.- Dng sa cc li 1 bt hoc pht hin cc li

nhiu bt. HEC ch dng sa s a i li tiu trnhtn tht tbo c th xy ra do mt nh hng v saili.

- Xc nh bin gii tbo- M ho theo CRC

T b ATM


46/73

10/1/2007 46

T bo ATMT bo ATM

Cc loi t bo ATM

- T bo gn A (Assigned Cell): l t bo ATMmang thng tin hiu lc ca ngi s dng hoc camng- Tbo khng gn UA (Unassigned Cell): l loi t

bo c hnh thnh lp ATM nhng cha thng

tin khng c hiu lc hot cha tiu c nhngha trc. Thng dng cho cc chc nngOA&M, bo hiu v.v

AT b ATM


47/73

10/1/2007 47

T bo ATMT bo ATM

Cc loi t bo ATM

- Tbo ri I (Idle Cell): c s dng lp vt l thch ng tc t bo ATM vi tc truyndn. Cc tbo ri c a vo u ngun vt l

v trit tiu u ch.- T bo hp l V (Valid Cell): L t bo khng bli pha thu hoc c li nhng c sa

- Tbo khng hp l IV (Invalid Cell): l tbo bli, c trng hp t bo b li m vn hp l dokhng pht hin c li. Tboli b hu lp vt

l, khng a l n lp ATM

T b ATMT b ATM


48/73

10/1/2007 48

T bo ATMT bo ATM

Cc loi t bo ATM

Lp ATM

Lp vt l

T bo gn T bo gn

T bokhng gn

T bokhng gn

T bori

T bokhng hp l

T bo

ri

HuPha pht Pha thu

PHN 2 : M HNH THAM CHIU GIAO THCPHN 2 : M HNH THAM CHIU GIAO THC


49/73

10/1/2007 49




2.2 Lp vt l ca B-ISDN2.3 Lp ATM ca B-ISDN


2 1 i i S


50/73

10/1/2007 50

2.1 M hnh tham chiu giao thc B-ISDN2.1 M hnh tham chiu giao thc B-ISDN

Hnh: M hnh tham chiu giao thc mng B - ISDN

2 1 M h h h hi i h B ISDN


51/73

10/1/2007 51


Cu trc

Gm 3 mt phng:- Mt phng ngi dng: cung cp cc chc nng chuyn tip lung thng tin ngi dng t u

cui n u cui cng nh cc chc nng iu khinlin quan v d nh: iu khin lung hay sa li.

- Mt phng iu khin: cung cp cc chc nngiu khin kt ni v k t ni cuc gi. Ngha l, mtphng ny cung cp cc chc nng lin quan n vic

thit lp, iu khin v g ii phng cuc gi.

2 1 M h h h hi i h B ISDN


52/73

10/1/2007 52


Cu trc

- Mt phng qun l: cung cp cc chc nng qunl mng (OAM). Mt phng qun l c chiathnh 2 mt:

Qun l mt: thc hin vic qun l ton b mng

Qun l lp: chc nng qun l cc tham s v ti

nguyn trong mi mt thc th mng (TE, NT) vqun l l ung thng tin OAM

2 1 M h h h hi i h B ISDN2 1 M h h th hi i th B ISDN


53/73

10/1/2007 53


Cu trc

Theo chiu dc chia thnh cc lp:- Lp vt l: lin quan n chc nng phng tintruyn dn (Tch tbo ri, hu cc tbo khng

hp l v.v)

- Lp ATM: truyn ti cc thng tin ti c c lp trn

di dng tbo- Lp AAL: Tng thch cc dch v khc nhau lp trn vi lp ATM v ngc li



54/73

10/1/2007 54


N : N C U G O CMNG B-ISDN

2.1 M hnh tham chiu giao thc B-ISD



2 2 L t l B ISDN2 2 L t l B ISDN


55/73

10/1/2007 55

2.2 Lp vt l ca B-ISDN2.2 Lp vt l ca B-ISDN

c chia thnh 2 phn lp:

Phn lp mi trng vt l (Physical dium) Phn lp hi t truyn dn (Transmission

Convergence)



56/73

10/1/2007 56


Phn lp mi trng vt l (Physical Medium)

- Chc nng mi tr ng vt l truyn dn: quy nhgiao din quang, cc bpht quang, thu quang,connector ..

- Chc nng nh thi bit: Bin i lung bit sangdng ph hp vi mi tr ng truyn dn, chn cc

thng tin nh thi, m ho v gii m ng. Ktqu l thng tin c truyn t lp PM ln lp TMch yu l cc lung bit/symbol v cc thng tin nh

thi tng ng



57/73

10/1/2007 57


Phn lp hi t truyn dn

- To v khi phc khung truyn dn

- Tng thch khung truyn dn: gn cc lung tboATM vo cc khung truyn dn, hay ngc li tch cc

tbo ATM t cc khung truyn dn.- Xc nh bin gii tbo (cell delineation):Xc nh

bin gii tbo trong lung tbo thu c

pha pht: thc hin chc nng chn trng HEC, trnphn thng tin.

pha thu: da vo HEC xc nh bin gii tbo,gii trn



58/73

10/1/2007 58


Phn lp hi t truyn dn

- To v k im tra tr ng HEC:

Pht: m ho 4 byte thnh 1 byte HEC

Thu: pht hin li, sa li

- Tng thch tc tbo: thc hin chc nng

chn tbo ri tng thch tc d ca lp t boATM truyn xung vi tc truyn lp vt l.



59/73

10/1/2007 59

MNG B-ISDNMNG B-ISDN




2 3 L ATM B ISDN2 3 Lp ATM ca B ISDN


60/73

10/1/2007 60

2.3 Lp ATM ca B-ISDN2.3 Lp ATM ca B-ISDN

- Lin quan n tt c cc trng tbo trong phntiu (tr HEC)

- VPI/VCI:To/tch tiu Ghp knh/tch knh cc tbo ATM

Bin dch t VPI/VCI c sang VPI/VCI mi ccnode chuyn mch- GFC:

iu khin lung t ngi s dng vo mng Chia s ti nguyn cho u cui- PT : gm 3 bit xc nh loi ti trng ca t

bo- CLP: xc nh u tin



61/73

10/1/2007 61






2 4 Lp thch ng ca B ISDN2 4 Lp thch ng ca B ISDN


62/73

10/1/2007 62

2.4 Lp thch ng ca B-ISDN2.4 Lp thch ng ca B-ISDN

- Gii quyt bt k s khc bit no gia dch v c

cung cp bi lp ATM cho ti khi p ng c ccyu cu dch v.

- Trong lp AAL ny cc n v giao thc lp caohn nh n v s liu dch v SDU ( Service DataUnit ) hay n v s liu giao thc PDU ( Protocol

Data Unit ) c b tr sp xp theo mt cch xcnh thnh cu trc d liu ca trng ti tin 48 Byteca t bo ATM. Lp ATM s thc hin ghp tiu

vi cc gi tr VPI/VCI thch hp cho cc t bo ny.



63/73

10/1/2007 63


Nhm n gin ho cc giao thc AAL v dch vcho khch hng rt phong ph a dng v khc nhau dovy rt kh ( thm ch khng th ) c mt giao thcchung cho mi dch v => Phn loi dch v B ISDNtheo cc tiu ch:

-Thi gian thc hay khng

- Tc c thay i khng

- Kiu kt ni

=> C 4 loi dch v: A,B,C,D



64/73

10/1/2007 64


Loidch v A B C D

Thi gian thc C C Khng Khng

Tc Khng C C C

Kiu kt ni CO CO CO CL

AAL AAL1 AAL2 AAL3/4,5

AAL3/4,5



65/73

10/1/2007 65


thc hin cc chc nng nu trn lp thch ngATM AAL c chia thnh hai lp con:

- Phn lp kt hp hi t CS ( Convergence Sublayer )

- Phn lp ct mnh v ti hp SAR ( Segmenting AndReassembling Sublayer ).



66/73

10/1/2007 66


Phn lp hi t

- CS thc hin chc nng phi hp v thch ng gia cc

lp cao v lp AAL, m bo cc tham s cht lng dchv QOS to cc thng tin dch v cho khch hng lp cao,cho cc hnh loi dch v ng dng, iu khin cc th tc

ng gi/ m gi cc mu gi s liu CS-PDU.- Chia thnh hai lp con: phn ph thuc dch v SSCS(Service Specific CS) v phn chung CPCS (Common Part

CS)trong SSCS c th l Null, ngha l khng cn CPCSlun lun phi thc hin kt hp vi SAR. Cc lp con ny

chuyn cc tin t nh cc PDU gia cc lp AAL - SAPti ATM - SAP



67/73

10/1/2007 67


Phn lp ct mnh v ti hp SAR

- Pha pht: c chc nng to cc t bo ATM tcc n v d liu t lp cao chuyn xung v nhdu c cc n v s liu pha ch,

- Pha thu: thc hin cc chc nng ngc li khi phc bn tin ban u t cc t bo ATM thu

c.



68/73

10/1/2007 68


Hnh: M hnh phn lp giao thc AAL.



69/73

10/1/2007 69


Hnh: M hnh phn lp giao thc AAL.

AAL - SDU

PayloadHeader Trailer

Header Trailer

48 byteHeader

Lp cao hn

CS

SAR

Lp AAL

Lp ATM

CS-PDU

SAR- SDU SAR- SDU Phn mnh

SAR-PDU

ATM -PDU



70/73

10/1/2007 70


CS PDU for AAL 3/4

- CPI: cho bit n v c s dng trng Basize

- B tag (Beginning )

E tag (Ending)

Btag v Etag ging nhau => pha thu so snh pht hin li- PAD thm vo phn payload l bi ca 4

- AL: thm vo trailer 4 byte

- LI: ch th di

1-65535 0-31 1 2

Payload PAD ALCPI Etag LIBtag BAsize

1 2 1



71/73

10/1/2007 71


CS PDU for AAL 5

- PAD thm vo phn payload l bi ca 4

- CS-UU: thng tin ngi dng - ngi dng trong sut

- CPI: xc nh CPI tung ng l phn chung hay khng

- AP: thm vo trailer 48 byte-LI: ch th di

-CRC : kim sot li

1-65535 0-47 1 42

Payload PAD CPI LICS-UU CRC

1



72/73

10/1/2007 72

PHN 2 : M HNH THAM CHIU GIAO THCMNG B-ISDNMNG B-ISDN




2 5 Cc lp c aoca B ISDN2 5 Cc lp c aoca B-ISDN


73/73

2.5 Cc lp c aoca B-ISDN2.5 Cc lp c aoca B-ISDN

Mt bng iu khin v bo hiu AAL( Control and Signalling plane AAL ).

Mt phng ngi dng. Mt phng qun l

Documents

Mang Tich Hop Da Dich Vu X-Isdn