bctnlvtntlvn (16)

7/31/2019 bctnlvtntlvn (16)

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LUN VN

ti:Xy dng thi quen c schcho tr trong gia nh

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Thnh ph H Ch Minh, thng nm ..


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Mc lc

M U ....................................................................................................................... 5S LC V CC BU IN TRUNG NG ......................................................6TNG QUAN MNG VIN THNG TH H SAU CC BU IN TRUNGNG ...........................................................................................................................6MC TIU V PHM VI CA MNG VIN THNG TH H SAU CC BUIN TRUNG NG ..................................................................................................6Cc hng mc cn thc hin .........................................................................................8Cu trc mng ...............................................................................................................8Cng ngh .....................................................................................................................9

Cu trc phn lp: .......................................................................................................10Cu trc mng ng trc (lp A) ..............................................................................12a. Thit b chuyn mch : ..........................................................................................12Cu trc mng lp truy nhp (lp B) ..........................................................................13CHNG 2 ................................................................................................................192.1. CC NGUYN L QUN L MNG VIN THNG ....................................192.1.4.1.Cc li ch chin lc: .................................................................................... 22

2.1.5.3. Cu trc chc nng TMN: ......................................................................242.1.5.4. Cc khi chc nng ........................................................................................25

Bng 2.1 Mi quan h gia cc khi chc nng vi b phn chc nng .............29

Khi ......................................................................................................................... 30Cc b phn chc nng ...........................................................................................30MAF ........................................................................................................................ 30ICF ........................................................................................................................... 30WSSF ......................................................................................................................30UISF ........................................................................................................................ 30DSF .........................................................................................................................30DAF ......................................................................................................................... 30SF ............................................................................................................................ 30OSF .........................................................................................................................30

M ............................................................................................................................. 30O .............................................................................................................................. 30O .............................................................................................................................. 30- ............................................................................................................................... 30O .............................................................................................................................. 30O .............................................................................................................................. 30O .............................................................................................................................. 30WSF ......................................................................................................................... 30Ch 2 .................................................................................................................... 30Ch 2 .................................................................................................................... 30

- ............................................................................................................................... 30M ............................................................................................................................. 30

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- ............................................................................................................................... 30O .............................................................................................................................. 30O .............................................................................................................................. 30

NEF q3 .................................................................................................................... 30M ............................................................................................................................. 30- ............................................................................................................................... 30- ............................................................................................................................... 30- ............................................................................................................................... 30O .............................................................................................................................. 30O .............................................................................................................................. 30O .............................................................................................................................. 30

NEF qx .................................................................................................................... 30O .............................................................................................................................. 30- ............................................................................................................................... 30- ............................................................................................................................... 30- ............................................................................................................................... 30O .............................................................................................................................. 30O .............................................................................................................................. 30O .............................................................................................................................. 30MF ........................................................................................................................... 30O .............................................................................................................................. 30M ............................................................................................................................. 30O .............................................................................................................................. 30- ............................................................................................................................... 30O .............................................................................................................................. 30O .............................................................................................................................. 30O .............................................................................................................................. 30QAF q3 .................................................................................................................... 30O .............................................................................................................................. 30M ............................................................................................................................. 30- ............................................................................................................................... 30- ............................................................................................................................... 30O .............................................................................................................................. 30O .............................................................................................................................. 30O .............................................................................................................................. 30QAF qx .................................................................................................................... 30O .............................................................................................................................. 30M ............................................................................................................................. 30- ............................................................................................................................... 30- ............................................................................................................................... 30O .............................................................................................................................. 30O .............................................................................................................................. 30O .............................................................................................................................. 30

Bng 1.2 Tu chn b phn chc nng i vi cc khi chc nng .......................30Hnh 1.6 :Chc nng TMN .................................................................................30

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CHNG 2 ................................................................................................................32GII THIU ...............................................................................................................32KIN TRC MPLS V C CH CHUYN TIP CA N ...................................39

3.2. QUN L MNG ........................................................................................... 533.2.1. KIN TRC QUN L MNG ..............................................................533.2.2. SNMP ........................................................................................................ 54

3.2.3. OAM TRN IP .............................................................................................. 563.2.3.1. Ping v ICMP .........................................................................................573.2.3.3. Cc chc nng OAM mi trong IPv6 .....................................................59

3.2.4. OAM TRN MPLS ....................................................................................... 593.2.4.1 Tng quan cc cng vic hin ti .........................................................593.2.4.2. Kt ni LSP ............................................................................................603.2.4.3. MPLS ping .............................................................................................623.2.4.4. Pht hin cc nt li RSVP ..................................................................623.2.4.5. Chuyn mch c bo v .........................................................................623.2.4.6. Ti nh tuyn nhanh ..............................................................................623.2.4.7. MPLS v xp xp lu lng ..................................................................63

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M U

Mng vin thng th h sau Cc Bu in Trung ng c bit di tn giMng truyn s liu chuyn dng ca cc c quan ng v Nhnc, hin nay d n xy dng mng c ng, Nh nc vcc c quan c chc nng ph duyt v c Tng Cng ty Bu chnhVin thng Vit Nam v Cc Bu in Trung ng gp rt trin khai.Mng vin thng th h sau Cc Bu in Trung ng c phm vi rt

rng, ph kn tt c cc tnh thnh trong c nc do vn t rasau khi xy dng xong l phi qun l mng nh th no thiu qu cao nht.

H thng qun l mng l khi c ca mng vin thng. Vi mt h thngqun l tt, mng s hot ng hiu qu, gim thiu s c v tng li nhun,uy tn ca nh khai thc.

Trn c s d n mng vin thng th h sau ca Cc Bu in Trung ng, ti a ra m hnh h thng qun l mng tp trung c kh nng qun l

mng trn phm vi ton quc.

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CHNG 1

GII THIU TNG QUAN V MNG TH HSAU CA CC BU IN TRUNG NG

S LC V CC BU IN TRUNG NG

Cc Bu in Trung ng l mt n v thnh vin ca Tng cng ty Buchnh Vin thng Vit Nam c giao nhim v phc v thng tin cho cc cquan ng, Nh nc. Mng Vin thng Cc BTW hin ang c trinkhai H Ni (CP16) , H Ch Minh (BT78) v 11 tnh Qung Ninh, Hi

phng, Nng, Tha thin - Hu, Cn Th v B Ra - Vng Tu, LaiChu, in Bin, c Lc, Kon Tum, Hu Giang. Ti cc im trn c lpt cc tng i a dch v bng hp (N-ISDN) phc v thng tin cho cc cquan Trung ng v c quan ng, chnh quyn a phng.

T nm 2002, Cc Bu in Trung ng c ng, Nh nc v Tng cngty Bu chnh Vin thng Vit Nam giao nhim v xy dng d n "Xy dngmng truyn s liu chuyn dng ca cc c quan ng v Nh nc", tin xy dng mng vin thng th h sau Cc Bu in Trung ng.

Chng ny s gii thiu mt ci nhn tng quan v mng vin thng th hsau m Cc Bu in Trung ng ang xy dng.

TNG QUAN MNG VIN THNG TH H SAU CC BU INTRUNG NG

MC TIU V PHM VI CA MNG VIN THNG TH H SAU CCBU IN TRUNG NG

Mng vin thng th h sau ca Cc Bu in Trung ng c xy dngda trn d n "Xy dng mng truyn s liu chuyn dng ca cc c quanng v Nh nc" vi mc tiu nhm xy dng mt mng ng trctruyn s liu chuyn dng thng nht cho mng tin hc din rng cng nhcung cp mt s cng thoi cho cc c quan ng v Nh nc. Mng cxy dng phi c tc cao, dung lng ln, da trn cng ngh IP, c ktni vi Internet.

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1.1.1.1. Mc tiu:

Mc tiu c th v cc yu cu t c th hin trn cc mt sau :

o

Xy dng mng kt ni t trung ng n cc tnh/thnh v n tncp qun, huyn, s, ban, ngnh; cung cp cc cng kt ni ti mngtin hc ca cc c quan ng, Nh nc ti cc cp vi tc cao,cng ngh m, hin i, trc tuyn c bit ng nht v giao din;t x, phng c th truy nhp vo mng din rng ca cc c quan

ng, Nh nc thng qua mng cng cng n thit b truy nhpt ti nt mng tnh/thnh ph.

o Trn c s h tng mng truyn s liu chuyn dng s trin khai a

dch v vin thng (thoi, truyn s liu - lin kt mng din rng vmt s dch v khc ty theo yu cu t cc c quan ng, Nhnc cng nh xu hng pht trin ca cng ngh).

o To thnh cc kt ni chiu dc theo kin trc phn cp ca cc cquan hnh chnh Nh nc cng nh tch hp theo chiu ngangmng thng tin din rng ca ng vi mng thng tin din rngca Chnh ph, Quc hi.

o Mng ng trc m bo thng sut, tin cy v an ton.

1.1.1.2. Phm vi:

Trn phng din v phn b hnh chnh ca cc c quan ng, Nh nc,phm vi ca mng vin thng th h sau Cc Bu in Trung ng bao gm :

o Mng truyn s liu chuyn dng ca cc c quan ng v Nhnc phc v vic kt ni mng din rng ca ng, Nh nc trn

phm vi ton quc, t cp trung ng n cp tnh, thnh ph v s,ban, ngnh, qun, huyn.

o Mng cung cp cc cng kt ni ra Internet tc cao ti H Ni vH Ch Minh.

o Mng cung cp cc dch v thoi, video cho cc c quan ng, Nhnc trn phm vi ton quc, t cp trung ng n cp tnh, thnh

ph v s, ban, ngnh, qun, huyn..

1.1.1.3. i tng s dng dch v:

Cc c quan di y l i tng c s dng cc cng kt ni ca mng

truyn s liu chuyn dng cng nh cc dch v gia tng c trin khai trnnn mng chuyn dng (thoi, video, Internet, ....) :

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o Cc c quan ng, Chnh ph, Quc hi cp trung ng.

o Vn phng tnh, thnh y (VPTU), y ban nhn dn (UBND), hing nhn dn (HND), cc s, ban, ngnh ti cc tnh/thnh trnton quc.

o Vn phng huyn/th/thnh y (VPHU, VPTU), y ban nhn dnhuyn/th/thnh (VP UBND huyn/th/thnh) trn ton quc.

Cc hng mc cn thc hin

Mng truyn s liu chuyn dng ca cc c quan ng, Nh nc bao gmcc hng mc sau :

o Cc nt mng cho mng truyn s liu ng trc: ba nt ti HNi, H Ch Minh v Nng.

o Xy dng cc nt mng kt ni t mng truyn s liu ng trcti cc tnh, thnh ph.

o Xy dng cc nt mng ti cc qun, huyn, s, ban, ngnh kt niv nt mng ti tnh, thnh ph.

o Xy dng cng kt ni Internet ti H Ni v H Ch Minh.

o Trin khai dch v in thoi h trung ng (ti mt s tnh cha ctng i in thoi m 80) trn nn mng truyn s liu chuyndng.

o Xy dng h thng bo mt ng truyn.

o Xy dng mi mt s tuyn cp quang/ng, ci to nh trm (tinhng ni khng tn dng c c s h tng hin c).

o Xy dng h thng qun l mng ng truyn s liu chuyn dngtp trung ti H Ni.

Trong cc hng mc trn, hng mc cui cng chnh l ni dung ti cnnghin cu.

Cu trc mng

o Mng ng trc (H Ni, H Ch Minh, Nng) t 155 Mbps.T nt mng ng trc vcc tnh/thnh ph ti thiu t 2Mbps.T tnh/thnh ph v qun, huyn, s, ban, ngnh ti thiu t64Kbps.

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o Ti cc tnh/thnh ph cc cng kt ni vo mng LAN ca VPTUv UBND c tch ring v chy trn cc ung cp quang ringnhng c th truy nhp ln nhau khai thc s liu khi lnh o c

thm quyn yu cu.o i vi cc tnh/thnh ph cha c tng i h I, mng truyn s

liu chuyn dng s cung cp thm mt s cng in thoi cho phpcc ng ch lnh o ch cht ti tnh/thnh v trung ng c thlin lc vi nhau trong mng ring (h 5 s).

o Mng c xy dng cho php phng thc kt ni qua quay s(analog, ISDN) vn c tip tc s dng i vi cc c quan mmng chuyn dng cha vn ti c hay nhng ngi khngngi ti phng lm vic c th ng nhp vo mng ni b qua ccknh truy nhp dnh ring.

o Cc Bu in Trung ng c u tin kt ni vo chuyn mch lica VDC vi tc cao trn cp quang ti H Ni v H Ch Minh phc v nhu cu truy nhp Internet ca cc c quan ng, Nhnc ti hai im ny.

Cng ngh

Mng vin thng th h sau Cc Bu in Trung ng c xy dng datrn cng ngh IP, h tr a phng thc kt ni (cp quang, cp ng) v

bng thng linh hot (trc tip: xDSL, n 64Kbps, n E1, STM1, FastEthernet, Giga Ethernet thng qua giao din kt ni ng nht l cngEthernet; gin tip: quay s qua mng in thoi analog, ISDN).

o S dng cc cng ngh tin tin nh MPLS, VLAN,.... tch ringcc mng din rng ca cc c quan ng, Nh nc ty theo chcnng nhim v ca cc c quan ny.

o H tr a dch v vin thng trn nn IP (thoi, truyn s liu,Internet , EMail, v cc dch v khc) trn c s tng thch vimng in thoi chuyn dng (mng in thoi h trung ng m80) hin c.

o Qun l tp trung t mt trung tm qun l mng duy nht ti HNi cho ton b mng ng truyn s liu, m bo thng sut,an ton, tin cy ca mng ng truyn s liu chuyn dng.

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o S dng cc cng ngh m ha ng truyn tin tin m boan ton cho ng truyn s liu, d liu trn ng truyn, chngmi kh nng c s truy nhp tri php vo h thng ng truyn.

o Vic s dng cc knh vt l ring (tch t knh truyn dn lintnh, ni tnh ca mng cng cng) dnh cho mng ng trc m

bo tnh u tin cao c tnh n ng truyn d phng (tnh vuhi), m bo truyn d liu truyn trong mng chuyn dng, trnhkhi bt c s tc nghn, gin on thng tin no ng thi vn m

bo tit kim u t mc cao nht.

o Trin khai hai cng ra Internet ti H Ni v H Ch Minh: hai cngra Internet ny phc v nhu cu kt ni Internet ca cc c quanng, Nh nc cp trung ng ti H Ni v H Ch Minh. T ccc quan cp a phng (tnh, thnh ph) c th kt ni ra Internetthng qua cc PoP Internet ca mng cng cng ti a phng.

Cu trc phn lp:

M hnh mng din rng ca cc c quan ng v Nh nc c m t trnhnh 1.1.

Hnh 1.1. M hnh mng din rng ca ng, Nh nc

Trong :

o Mc A : Cp Trung ng.

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PA ( Trung ng)

PB (Tnh)Tnh y,UBND

PB (B,Ngnh)

Ban cn sng

PC

(S)

PC(Cc, V, n v tng

ng)

PD(X,

phng)

PC(Qun,

huyn)


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o Mc B : Cp B, Tnh.

o Mc C : Cp S, Ban, Ngnh, qun, huyn, th hoc Cc, V, n vtrc thuc B.

o Mc D : Cp x, phng.

Cu trc phn lp ca mng th h sau Cc Bu in Trung ng nh hnh1.2.

Hnh 1.2. M hnh mng theo cu trc phn cp

Trong :

o Lp chuyn mch li: t ti H Ni, H Ch Minh, Nng lm nt tp trung lu lng cho cc tnh trong vng , c kt nivi tc STM-1 (155Mbps). Cc nt chuyn mch lp ny cu vi nhau cu trc 2 hng chn (1+1) m bo an ton.

o Lp truy nhp: Kt ni v lp chuyn mch li qua cc cng n xE1, Fast Ethernet (100 Mbps) hoc STM-1 (ty theo lu lng d liuv kh nng b tr knh truyn dn).

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Chuyn mchli (HNI)

Chuyn mchli (DNG)

Chuyn mchli (HCM)n x STM-1( n x 155Mbps)

n x E1, Fast Ethernet, STM-1

..

n x 64Kb n x E1 xDSL GigaEthernet

FastEthernet

Lp li

Lp truy nhp

Lp u cui

Mng LANca cc c quan ng, Nhnc cc cp TW, tnh,huyn ( tc kt ni theoyu cu )

Cng Ethernet

Mng LAN

STM-1

Lp truy nhp (ti cc tnh/ thnh ph)


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o Lp u cui: Bao gm cc u cui t ti pha mng ca cc cquan ng, Nh nc; kt ni v lp truy nhp thng qua knh n xE1,xDSL, STM-1, FastEthernet hay Giga Ethernet khi c yu cu. Lp u

cui cung cp cc giao din kt ni thng vo HUB, LAN Switchca mng LAN ca cc c quan ng, Nh nc vi tc 10 Mbps,100 Mbps hay 1000 Mbps (GE)

o .

o Lp Extranet (cung cp cng ra Internet t mng ni b) : vic cungcp kt ni ra Internet do 02 PoP t ti H Ni v H Ch Minh mnhim.

o H thng qun l gim st mng (NMS): t ti H Ni c kh nnggim st, vn hnh, tnh cc, .... ton mng truyn s liu ni b vmng cung cp cng kt ni Internet, bn cnh h thng qun lmng cng phi h tr kh nng gim st, vn hnh t xa cho cc trmti cc nt mng mc B, C theo m hnh khng s dng ngi trcthng xuyn. y chnh l mc tiu ca lun vn.

Cu trc mng ng trc (lp A)

Mng ng trc bao gm cc trung tm H Ni, H Ch Minh v Nng

bao gm:a. Thit b chuyn mch :

a. L cc chuyn mch nhiu lp h tr cc giao tip 10/100/1000Mbps, chuyn mch a tng 2/3/4 v chnh sch lu lng htr tt nht cho cc dch v trung tm d liu .

b. m nhim chc nng chuyn mch lu lng mc cao, ngthi cung cp cc cng kt ni cho cc trung tm d liu ca

cc c quan ng, Nh nc (hosting), u trc tip vo lpmng B ca khu vc H Ni, H Ch Minh, Nng.

b. B nh tuyn ng trc ( Backbone-Router ):

a. Cung cp kh nng kt ni gia cc nt mng trung tm vi nhau(u cho 1+1), kt ni v lp mng B.

b. To thnh mt backbone gia cc nt mng trung tm (chuynmch IP lp li ), tc kt ni l STM-1 tr nn.

c. nh tuyn mc ng trc.

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Hnh 1.3. M hnh mng ng trc

Cu trc mng lp truy nhp (lp B)

Nh m t trn, lp truy nhp s bao gm cc thit b m nhim ccchc nng sau :

o Kt ni v lp mng ng trc.

o Chuyn mch ni b ca khu vc (tnh/thnh s ti).

o Cung cp mt s cng in thoi.o Cung cp cc giao tip kt ni n lp mng C.

a. Lp mng B ti H Ni, H Ch Minh, Nng

Lp mng B ti H Ni, H Ch Minh, Nng c phn tch y lthuc mng Cc BTW nhm phc v kt ni cho cc c quan cp trungng phn bit vi phn mng phc v cho cc c quan cp tnh/thnh, ...

C mt s im khc bit so vi mng lp B ti cc tnh/thnh khc l:

o Mng ti H Ni, H Ch Minh, Nng da trn cu trc vngRING cp quang hin c ca Cc Bu in Trung ng phc vnhu cu kt ni ca cc c quan ng, Nh nc, Quc hi ng tiH Ni, H Ch Minh, Nng.

o Cung cp cc cng kt ni v mng ti cc tnh/thnh ( y lpmng B ca H Ni, H Ch Minh, Nng m nhim mt phnchc nng ca lp li nhm phn chia ti x l trn mng).

o

u trc tip vo thit b chuyn mch ca lp li thng qua cng100/1000 Mbps.

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IP/MPLSII

Nng

H NiHH

Tp. H Ch MinhTT

STM-1SS

STM-1SSSTM-1SS

LAN SwitchLL

InterPoP-RouterI


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Trong :

Trung k kt ni t Access Router n tng i ti H Ni v H Ch Minhgm 2 nhm :

o Nhm 1: kt ni cho php cc cuc in thoi vo/ra t mng inthoi bn ngoi (PSTN, cc my h 5 s Cc BTW ca tng iMD110 hin c) vi cc my in thoi h 5 s do mng truyn sliu ni b cung cp.

o Nhm 2: cho cc kt ni vo mng truyn s ni b qua truynhp gin tip (analog/ISDN). Cc kt ni ny c th c p dngi vi c quan c mng LAN nh hay cha kp chuyn sang s

dng kt ni mi cng nh cho ngi dng i cng tc sang aphng khc c th truy nhp v mng LAN ca mnh.

Hnh 1.4. M hnh kt ni mng lp B ti H Ni, H Ch Minh

b. Lp mng B tnh/thnh ph khc

T hnh 1.5, c th lit k cc thit b thuc lp mng ny nh sau:

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Core LAN Switch

IP-MUX

RING cp quang

B tp trungDSLAM

DSLAM

DSLAM

DSLAM

DSLAMIP-MUX

cng xDSL

cng FE/GE

LeasedLine

n cctnh/thnh

nxE1

Mng ng trc

Access Router

TiMD110

Soft Switch

Thoi/video


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B nh tuyn (Uplink/Access Router): nh tuyn cho khu vc,kt ni vlp mng trn. Tc kt ni c th l nxE1, E3, Fast Ethernet, STM-1.ng thi l Router truy nhp, cung cp kh nng kt ni n lp mng C,

cng nh cho php cc kt ni thng qua cng analog vo mng truyn sliu ni b.

Chuyn mch LAN (LAN switch): m nhim nhim v chuyn mch chophn mng, cung cp cc dch v trung tm d liu cng nh h tr cc cngkt ni tc cao (FE/GE).

Thit b truy nhp:

o Thit b DSLAM : cung cp cc cng xDSL.

o Thit b IP-MUX : cung cp cc cng nx 64Kbps, 2 Mbps cho ktni v cc nt mng xa thng qua truyn dn ni tnh.

o Thit b cung cp cc cng in thoi analog.

Tc kt ni t nt mng thuc lp mng ny (lp B) v lp ng trc tithi im ban u l n x E1, tuy nhin ty theo yu cu v bng thng camng my tnh cc c quan ng, Nh nc cng nh kh nng b tr knhtruyn dn ca Ngnh, c th nng cp ln tc cao hn (E3, STM-1, ...) mkhng cn phi thay th bt c thit b no (ch cn thay i bng mch giaotip kt ni c kh nng h tr tc cao hn).

1.1.1.4. Cu hnh mng truyn s liu ti lp C

Ti cc nt mng lp C c mt s phng thc kt ni sau :

1. kt ni vo cc mng LAN ln ( VPCP, VPTW, VPQH hay UBND-HND/VPTU ca cc tnh/thnh,... ) s dng kt ni trn cp quangtc cao ( nu cha c tuyn cp quang th xy dng mi ), cc thit

b u cui s dng cc thit b chuyn i quang /in nh Gigabit

Interface Converter hay Fast Ethernet Converter.

2. Vi cc s, ban, ngnh, qun, huyn ni th hay khong cch ph hpv c th b tr c i cp ng th dng cc thit b xDSL ktni.

3. Vi cc im mng lp C xa nt mng lp B hay phi s dng knhtruyn dn ni tnh tc n x 64 - 2Mbps th dng cc thit b kt cuimng (NTU) kt ni.

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Hnh 1.5. M hnh kt ni mng lp B ti cc tnh/thnh khcMt s giao din h tr cc kt ni thng qua cng quay s in thoi(analog/ISDN) truy nhp vo mng ni b, giao din ny c dng chocc c quan cha kp chuyn sang s dng h tng truyn thng mi hay chonhng ngi dng di ng ( v d i cng tc xa c quan), c th kt ni vmng my tnh ca c quan mnh thng qua cc cng truy nhp s dng quays in thoi. Sau khi kt ni thnh cng vo mng truyn s liu ni b,mng s to ra mt knh kt ni o n mng din rng ca c quan tng

ng (ca VPTW hoc VPCP ) v t ngi dng phi nhp tip cc thngtin xc thc thc s kt ni vo mng my tnh ca c quan mnh ).

1.1.1.5. Kt lun

Nh trnh by trn, ta c th khi qut v mng vin thng th h sau caCc Bu in Trung ng nh sau:

Cng ngh:

o Giao thc: TCP/IP.

o Cng ngh cho mng ng trc: cng ngh MPLS.

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B nh tuyn(Uplink-AccessRouter)

Thit b Chuyn mch

Thit b truy nhp( Access Devices)

Modulethoi

xDSL, FE,.... in thoi Truy nhp quay s, LL,...

n x E1( c th nng ln E3hay cao hn )

Mng ng trc


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Lun vn tt nghip

o Cng ngh cho mng truy nhp:

Qua cp quang FE/FO tc 100/1000 Mbps i vi VPCP,VPTW, VPQH, cc b, c quan ngang b, tnh/thnh y, UBNDtnh/thnh ph.

Qua modem xDSL tc 2Mbps i vi cc S, Ban, Ngnh.

Qua WAN (NTU) tc nx64 Kbps ti cc qun, huyn.

Giao din kt ni u l Ethernet.

Hnh 1.6. M hnh kt ni mng lp C

K thut:

o

Mng ng trc gm 3 nt mng ti H Ni, H Ch Minh, Nng. Ti H Ni v H Ch Minh cn c thm cc tng i chuynmch mm cung cp kt ni thoi/video v ti y cng cung cpthm cc kt ni Internet phc v hnh chnh cng.

o Mng truy nhp ti cc tnh, thnh kt ni v cc core PoP ti ccmin tng ng.

o Mng kt cui: Cung cp kt ni n ngi s dng.

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Lp mng B

xDSL orleaselin

e

NTU hoc xDSL modemNN

Router hoc FE/GEConverterCC

Mng in thoicng cng.

Ngi dng s dngkt ni quay s inthoi kt ni

(analog/ISDN)

Kt ni mng vo mngTSL qua mng in thoicng cng (PSTN).


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1.1.2. CHC NNG CA H THNG QUN L MNG TH H SAUCC BU IN TRUNG NG

Mc tiu ca lun vn l xy dng c h thng qun l mng th h sauCc Bu in Trung ng trn nguyn tc qun l tp trung t mt trung tmduy nht. Cc yu cu v h thng qun l mng ny nh sau:

o Qun l s c: quan tm n cc s kin mng li nh l cc cnhbo v cc qu trnh cn thit x l chng.

o Qun l ti nguyn: qun l cu trc ca tt c cc cc lp ca mngkhi c thay i cc ti nguyn thit b v cc phn mm.

o Qun l cu hnh: sp t cc ta nguyn ln ton b mng li v

qun l s cung cp, di chuyn, thay i, nh tuyn li khi c hnghc hay tc nghn

o Qun l truy cp v an ton: kim sot s truy cp vo mng lii vi cc i tng c php.

o Lu tr, sao lu d liu: m bo s an ton d liu.

V mng th h sau Cc Bu in Trung ng c xy dng trn nn tngcng ngh IP/MPLS nn trong cc chng tip theo s trnh by r v cc

cng ngh ny cng nh cc cng ngh qun l trong mng IP/MPLS.

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CHNG 2TNG QUAN V H THNG QUN L MNG

TMN

2.1. CC NGUYN L QUN L MNG VIN THNG

Mng vin thng ngy cng tr nn a dng v c ph bin rng ri. Trongsut nhng nm 90 ngi ta trng i mng vin thng cng vi h thng

phn mm c s s dng hng ngn phn t mng thng minh s tin trintng theo cc dch v m li gim c gi thnh duy tr hot ng v qunl mng. T nm 1988 ITU-T cng b mt s khuyn ngh v nhng thtc, cu trc, giao din tiu chun tp hp thnh b khuyn ngh M.3000 - chnh l mng qun l vin thng TMN, mt gii php v ang c trinkhai rng ri.

TMN cung cp nhng thng tin v chc nng qun l mng nh: iu khin

hot ng, qun l, vn hnh trong mi trng a phng tin, phc tp camng vin thng. Chc nng ca TMN c th c chia ra lm hai loi chnhl chc nng c bn v chc nng m rng.

Phn ny s cp ti mi quan h gia TMN v mng vin thng; cu trc,cc giao din chun v phn b ca TMN.

Chng hai s xem xt v h thng qun l mng TMN v nh gi xem hthng qun l mng TMN c thch hp vi vic xy dng h thng qun lmng cho mng th h sau ca Cc Bu in Trung ng hay khng. Trong

mi mc u c cc so snh v nh gi v s ph hp .2.1.1.

QUAN H GIA TMN V MNG VIN THNG

TMN c th dng rt n gin l mt kt ni gia h iu hnh (OperatingSystem) ti mt thit b vin thng no , hoc dng rt phc tp l mngkt ni nhiu h iu hnh vi nhiu h thng vi cc thit b u cui khcnhau. Trn hnh 2.1 biu din mi quan h gia mt mng TMN vi mng

vin thng TN m n qun l.

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Mt mng qun l c th cung cp cc chc nng qun l v s lin lc giah iu hnh (OS) v cc phn khc nhau ca mng vin thng. TMN cngcung cp chc nng qun l v lin lc ti cc TMN khc hay cc thc th

tng ng TMN h tr kh nng qun l mng ton quc hoc quc t.Mng vin thng bao gm cc loi thit b tng t, s nh thit b tng i,truyn dn, thit b u cui, thit b kim tra bo dng, trong mng qunl cc thit b ny u c xem l phn t mng (NE Network Element).

Mt cch tng qut, TMN l mt mng ring c lp v mt logic vi cqun l, giao tip vi mng vin thng mt s im nhn hay gi thngtin iu khin hot ng ca n. TMN s dng cc thnh phn ca mngvin thng cung cp cc thng tin ca mng.

Hnh 2.1: Quan h gia TMN v mng vin thng

2.1.2. CC LNH VC NG DNG CA TMN

Theo khuyn ngh M.3010, sau y l mt s v d v cc mng, cc dch vvin thng v mt s thit b chnh c th qun l bi TMN:

o

Cc mng cng cng v mng ring bao gm cc mng a dch vISDN bng rng v bng hp (bao gm c ATM), cc mng thng

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Ti TMNkhc

Mng vin thng

Chuynmch

H thngtruyn dn

H thngtruyn dn

Chuynmch

Chuynmch

Mng thng tin s liu

H thngiu hnhH thng

iu hnhH thngiu hnh

Trmlm vic

TMN


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tin di ng, cc mng thoi ring, cc mng ring o v cc mngthng minh.

o Bn thn TMN.

o Cc thit b truyn dn (cc b ghp knh, cc b phi lung, thitb chuyn knh SDH)

o Cc h thng truyn dn s v tng t (cp kim loi, cp siquang, v tuyn, v tinh)

o Cc h thng lu tr.

o Cc h iu hnh v thit b ngoi vi ca chng.

o Cc b iu khin nhm, my ch, cc b x l ph cn, cc mytnh ln.

o Cc tng i s v tng t.

o Cc mng WAN, LAN, MAN.

o Cc mng chuyn mch gi v chuyn mch.

o Cc h thng v thit b u cui bo hiu bao gm cc imchuyn tn hiu (STP Signal Transfer Point) v c s d liu thi

gian thc.o Cc dch v vin thng v cc dch v km theo.

o PBXs, truy nhp PBX v u cui ngi s dng (khch hng).

o Cc u cui ngi s dng ISDN.

o Phn mm c cung cp bi cc dch v vin thng hoc lin quanvi cc dch v vin thng, phn mm chuyn mch, ng dn,cs d liu bo hiu.

o Phn mm ng dng hot ng trong cc my tnh ln (siu mytnh) bao gm c cc ng dng cung cp cho TMN.

o Cc h thng lin quan (cc module o kim tra, cc h thngngun, iu ha nhit , cc h thng cnh bo ca mt to nh,)

Nh vy, cn c vo cc ng dng ca TMN ta thy rng TMN ph hp vivic xy dng h thng qun l mng ca Cc Bu in Trung ng. Tuynhin, xem xt xem c th p dng hay khng cn phi nghin cu cc c

trng khc ca mng qun l vin thng TMN.2.1.3 MC TIU C BN CA TMN

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Mc tiu c bn ca ca TMN l cung cp mt c cu t chc cho qun lvin thng. Ngoi ra cc mc tiu xy dng TMN l:

o T mt hoc mt vi h thng qun l, ngi iu hnh c th qunl nhiu mt cc loi thit b, mng, dch v phn b rng ri.

o Cc c ch bo mt v ton vn d liu nhiu mc nh qun l hthng, cc chc nng lin lc bi v TMN c th cho php truy cpv iu khin t cc ngun c coi l bn ngoi TMN.

o Tng thch vi cc ng dng c bn ca m hnh OSI.

o Dng k thut x l phn b hng i tng (ODP) vi nhn lcc i tng qun l cc ti nguyn trong mi trng TMN bi

mi trng qun l vin thng phn b.2.1.4. LI CH CA VIC S DNG TMN

Vic trin khai mng qun l vin thng TMN mang li cc ch li sau ycho cc nh khai thc, cho khch hng v c i vi cc nh sn xut cungcp thit b:

2.1.4.1.Cc li ch chin lc:

- Lin kt cc nh sn xut, cung cp thit b.

- Tc ng ln n cc hoch nh v chnh sch trong kinh doanh.

- Thc hin tt cc chc nng bo v, bo mt cho mng.

- Cung cp kh nng iu chnh k hoch khai thc v kinh doanh.

2.1.4.2.Cc dch v cho khch hng c ci thin:

- Cht lng dch v c nng cao.

- Chuyn giao sn phm nhanh hn.

- Theo di v p ng tt cc yu cu ca khch hng.- Khch hng c th tham gia vo vic qun l dch v.

2.1.4.3.Gi thnh cc dch v v thit b c gim i:

- Cc thit b c chun ho.

- Phn chia li c s h tng.

- Kim tra v thit k chi tit.

2.1.4.4.Tng li nhun kinh doanh:

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- Qun l cht ch mng khch hng.

- Bn li cc h thng.

- Cc gi tr c ti ci thin.Vic p ng cc tiu chun t c cc li ch trn ph thuc vo:

- Tnh nng v c im ca cc phng tin c cung cp trong hthng qun l.

- Kh nng gim st, kim sot cc b phn ca mng qun l.

- C cu t chc v phng thc iu hnh c xy dng khai thcvic qun l mng.

2.1.5. CU TRC MNG TMN2.1.5.1. Cc yu cu v cu trc TMN:

- Ti thiu ho thi gian hot ng qun l i vi cc s c trn mng.

- Kh nng iu khin theo cc hng ca vic vn hnh mng.

- Cung cp c cu c lp ti thiu ho nh hng nguy hi i vivic bo mt.

- Xc nh v tr, nguyn nhn v ni dung ca cc li mng.

- Cung cp dch v h tr v s lin kt vi khch hng.

2.1.5.2. Cu trc ca TMN:

i vi cu trc tng quan ca TMN khi lp k hoch v thit k c 3 xuhng cu trc sau y c nghin cu xem xt, l:

- Cu trc chc nng TMN: phn b cc chc nng trong TMNcho php khi to cc khi chc nng m t mt TMN s c to

thnh t t hp cc khi chc nng ny. nh ngha v cc khi chcnng v cc im lin quan gia cc khi chc nng s dn ti cc yucu i vi cc tnh nng giao din c khuyn ngh i vi TMN.

- Cu trc thng tin TMN: Da trn c s i tng l nguynnhn c bn p dng kt ni h thng m OSI. OSI v nguyn lX500 l c s a ra nguyn tc TMN v c m rng thchhp vi mi trng TMN khi cn thit.

- Cu trc vt l TMN: trnh by cc giao din thc v cc v d

v cc thnh phn vt l i vi TMN.

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2.1.5.3. Cu trc chc nng TMN:

TMN cung cp cc phng tin truyn ti v x l thng tin lin quan nvic qun l cc mng vin thng. Cu trc chc nng ca TMN c datrn mt s khi chc nng ca TMN. Cc khi chc nng cung cp choTMN cc chc nng gip cho vic thc hin cc chc nng qun l TMN.Chc nng truyn thng d liu DCF c s dng chuyn i thng tingia cc khi chc nng TMN. Cc khi chc nng khc nhau in hnh cth l mc gii hn v phm vi thc hin ti cng im chun. Chc nngc cung cp bi cc khi chc nng ca TMN s c trnh by chi tithn trong cc b phn chc nng cu thnh TMN. Cc khi chc nng caTMN c minh ho nh hnh 2.2.

Hnh 2.2: Cc khi chc nng TMN

Trong :

OSF: Operation Systems Function Chc nng h thng vn hnh

MF: Media Funtion: Chc nng trung gian

WSF: Work Station Function Chc nng trm lm vic

NEF: Network Element Function Chc nng phn t mng

QAF: Q Adaptor Function Chc nng tng thch Q

: ng bin chc nng TMN.

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WSF

MFMMM

NEFQAF

OSF

TMN


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2.1.5.4. Cc khi chc nng

* Khi chc nng iu hnh (OSF):

OSF cung cp chc nng lp k hoch v qun l cho mng TMN. OSF x lthng tin lin quan n vic qun l vin thng nhm gim st/phi hp v cth iu khin cc chc nng vin thng. Hin ti c rt nhiu OSF cn thitcho vic hot ng ca TMN, cc t chc chun ho ang c gng nh racc loi OSF c th c thc hin bi cc h thng vt l. Theo tiu chunM.3010 ca ITU th c 4 loi OSF cung cp chc nng qun l cc lp: lpkinh doanh BML, lp dch v SML, lp mng NML v lp qun l cc thnh

phn mng NEML.

* Khi chc nng phn t mng (NEF):- NEF l mt khi chc nng thng tin vi TMN nhm mc chc gim st v/hoc c iu khin. NEF cung cp cc chc nngvin thng v h tr c yu cu bi mng vin thng ang cqun l.

- NEF gm cc chc nng vin thng l cc vn qun l.Cc chc nng ny khng phi l mt phn ca TMN nhng i dincho TMN thng qua NEF. Phn ca NEF cung cp s biu th ny

trong vic h tr TMN l mt phn bn thn TMN trong khi bnthn cc chc nng vin thng l nm ngoi NEF.

* Khi chc nng trm lm vic (WSF):

WSF cung cp phng tin din gii thng tin TMN cho ngi s dng vngc li. WSF chu trch nhim chuyn i thng tin gia im chun TMNv im chun khng thuc TMN ng vi tr nh mt cng giao tip, dovy mt phn ca khi chc nng ny nm ngoi ng bin.

* Khi chc nng trung gian (MF):Khi MF cho php cc khi chc nng khc trong TMN trao i thng tin vinhau khi giao din v im tham chiu gia chng khng ging nhau. Nicch khc MF c nhim v nh cc cng lm nhim v chuyn tip. Theo cctiu chun M30/3010 ca ITU khi MF cn c nhim v x l v trao ithng tin qua li gia OSF v NEF (hay QAF) m bo s tng thch cathng tin gia cc khi chc nng gn vi MF. Mt s v d v chc nng caMF.

Truyn ti thng tin

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Chuyn i cc th tc

Chuyn i cc bn tin v tn hiu

Phin dch a ch nh tuyn

Lm b tp trung

X l thng tin

Thc hin lnh

Lu tr, sa cha, lc, t ngng v iu chnh li thng tin

* Khi chc nng tip hp Q (QAF):

Khi QAF c s dng kt ni b phn ca TMN (nh NEF hoc OSF)vi bn ngoi khng thuc TMN. Nhim v ca QAF l chuyn i thng tingia im chun TMN vi im chun khng thuc TMN, do vy mt phnca khi chc nng ny nm ngoi ng bin.

2.1.5.5. Cc b phn chc nng TMN:

Mt s b phn chc nng c xc nh l phn t to nn cc khi chcnng ca TMN v c xc nh trong mc ny. Bng 2.1 ch ra bng cch

no cc b phn chc nng ny c t hp thnh cc khi chc nng khcnhau. Bng 2.2 ch ra mi quan h ca cc b phn chc nng vi cc khichc nng.

* Chc nng p dng qun l (MAF):

MAF din t phn chc nng ca mt hoc nhiu dch v qun l TMN nh trnh by trong khuyn ngh M 3020 v c tng qut ho trong khuynngh M.3200. MAF c th c c tnh ho bi cc kiu khi chc nng ca

n, v d MF-MAF, OSF-MAF, NEF-MAF v QAF-MAF. iu khin cc dch v qun l TMN hay phi hp tng tc gia MAFtrong cc khi chc nng khc nhau th cn c s gip cc b phn chcnng khc. Mi tc ng qua li c bit l chc nng qun l TMN linquan n mt hoc nhiu cp MAF phi hp. Chc nng qun l TMN linquan c nhm li thnh tp hp chc nng qun l TMN v c trnh bytrong khuyn ngh M.3400.Tp hp chc nng qun l TMN ny c th cuthnh tt c cc chc nng qun l TMN c cung cp bi mt MAF ring

bit.

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Chc nng h thng vn hnh Chc nng ng dng qun l (OSF-MAF): Cc chc nng ng dng qun l ny rt quan trng v l mt

phn ca OSF. Chng c di chc nng t n gin n phc tp nh l:

Tr gip vai tr ca qun l v Agent trong vic truy nhp nthng tin i tng c qun l.

Cng thm gi tr vo thng tin ban u, v d tp trung d liu, sali cnh bo, phn tch ch tiu cht lng, thng k

Tng tc vi thng tin n, v d ti cu hnh t ng, bm li

Cc chc nng khc (ang tip tc nghin cu).

Chc nng phn t mng- Chc nng ng dng qun l (NEF- MAF):Cc chc nng ng dng qun l ny trnh by trong QAF, ch yu htr vai tr nh qun l v tc nhn (Agent) ca n. Cc kha cnh khcvn ang tip tc nghin cu.

Chc nng tng thch Q - Chc nng ng dng qun l (QAF-MAF):Cc chc nng ng dng qun l ny trnh by trong QAF,ch yu htr vai tr nh qun l v tc nhn ca n.Cc kha cnh khc vn angtip tc nghin cu.

Chc nng trung gian Chc nng ng dng qun l (MF-MAF): Ccng dng qun l ny c biu th MF trong vic h tr chc nngchuyn i thng tin. V d v cc chc nng nh vy l:

m bo t hp d liu thng qua th tc trung gian,

Tp trung, ti nh dng v tnh hiu lc ca d liu,

To ngng gii hn, nh tuyn/ti nh tuyn d liu,

m bo rng chc nng chuyn i thng tin c thc hin ph

hp vi c quyn truy nhp ca cc i tng s dng TMN* Chc nng chuyn i thng tin (ICF):

ICF c s dng gia cc h thng trung gian nhm cung cp c ch chuyni thng tin gia cc m hnh thng tin vi cc giao thc ti c hai giao din.Cc m hnh thng tin ny c th hoc khng th c nh hng i tng.

* Chc nng tr gip trm cng tc (WSSF):

WSSF h tr cho khi chc nng (WSF) bao gm c truy nhp d liu v

thao tc, dn chng v khng nh hot ng, truyn dn thng bo v chedu s tn ti ca NEF v OSF khc i vi i tng s dng WSF truyn

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thng vi OSF ring. WSSF cng c th h tr trong vic iu hnh WSF vtruy nhp i vi vic iu hnh OSF.

* Chc nng tr gip giao din i tng s dng (UISF):

UISF chuyn i thng tin trong m hnh thng tin TMN ti nh dng c thhin th i vi giao din ngi my v chuyn i li vo i tng sdng n m hnh thng tin TMN. UISF chu trch nhim v t hp thng tint mt hoc nhiu on c mt hoc nhiu OSF, ng thi UISF cn c thcung cp chc nng tng t nh MAF v ICF.

* Chc nng h thng th mc (DSF):

B phn chc nng DSF a ra mt h thng th mc phn b kh dng ton

cu hoc ni ht.Thut ng th mc c s dng y trong mt nghachung.N khng ng cho mt trng hp ring no v thc hin cu trc dliu kt hp vi thng tin ny.Chc nng yu cu c th thc hin vi c sd liu lu tr i tng c qun l ,i tng trong th mc

* Chc nng truy nhp th mc(DAF):

B phn chc nng ca DAF c kt hp vi tt c cc khi chc nng cnthit truy nhp ti th mc. N c s dng truy nhp ti v/ hoc duytr thng tin lin quan TMN biu th thng qua cc chc nng h thng thmc (DSF).

* Chc nng bo mt (SF):

B phn chc nng bo mt cung cp cc dch v an ton cn thit cho cckhi chc nng tho mn chnh sch bo mt v/hoc yu cu ca ngi sdng. Tt c dch v bo mt m khi chc nng c th c phn thnh 5dch v c bn: Xc nhn, iu khin truy nhp, tin cy d liu, t hp dliu v an ton nh trnh by trong khuyn ngh X.800.

* Khi chc nng truyn thng bo (MCF):

MCF c kt hp vi tt c cc khi chc nng c giao din vt l. N cs dng v c gii hn, cho s thay i thng tin qun l cha ng thng

bo tng xng vi n. MCF hp thnh ngn giao thc cho php kt ni cckhi chc nng ti chc nng thng tin d li DCF. MCF c th cung cpcc chc nng hi t giao thc cho giao din khng phi tt c 7 lp OSI c tr gip. Ph thuc ngn giao thc c tr gip im tham chiu,cc loi MCF khc s tn ti. Khi mt khi chc nng c kt ni hai loigiao din cn c hai loi MCF cung cp s chuyn i giao thc.

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Khi chc nng Cc b phn chc nngOSF d) OSF-MAF (A/M), WSSF, ICF, DSF, DAF, SFWSF UISF, DAF, SF

NEFq3a)

NEF-MAF (A), DSF, DAF, SFNEFqx a) NEF-MAF (A), DSF, DAF, SFMF d) MF-MAF (A/M), ICF, WSSF, DSF, DAF, SFQAFq3 b) d) QAF-MAF (A/M), ICF, DSF, DAF, SFQAF qx c) QAF-MAF (A/M), ICF, DSF, DAF, SF

Bng 2.1 Mi quan h gia cc khi chc nng vi b phn chc nng

A/M Agent/Manager : Tc nhn/Qun lDAF Directory Access Function : Chc nng truy cp th mc

DSF Directory System Function : Chc nng h thng th mcICF Information Conversation Function : Chc nng chuyn i thng tinMCF Message Communication Function : Chc nng truyn thng ipMAF Management Application Function : Chc nng ng dng qun lSF Security Function : Chc nng bo mtUISF User Interface Support Function : Chc nng h tr giao din ngi sdngWSSF WorkStation Support Function : Chc nng h tr trm lm vic

a) NEF cng bao gm cc ngun vin thng v h tr bn ngoi TMNb) Khi QAF q3 c s dng trong vai tr qun l, cc im tham chiu q3nm gia QAF v OSFc) Vic s dng QAF qx trong vai tr qun l l nghin cu su hnd) MAF(A/M) ngha l chc nng ng dng qun l trong vai tr tc nhnhoc qun l.

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KhiChc nng

Cc b phn chc nng

MAFCh 1

ICF WSSF UISF DSF DAF SF

OSF M O O - O O OWSF Ch 2 Ch 2 - M - O O

NEF q3 M - - - O O ONEF qx O - - - O O OMF O M O - O O OQAF q3 O M - - O O OQAF qx O M - - O O O

Bng 1.2 Tu chn b phn chc nng i vi cc khi chc nng

M: Mandatory :Bt bucO : Optional:Tu chn- : Khng cho phpCh 1 : MAF c xem xt thm vo cc hot ng tc nhn hoc qunl v c th mu thun vi cc nh ngha ISOCh 2 : Cc chc nng ny c th xem l mt phn ca UISF

Nh trn ta thy v mt chc nng TMN2.1.5.6. Chc nng thng tin d liu DCF ca TMN

Cc khi chc nng TMN s s dng chc nng truyn thng d liu (DCF) chuyn i thng tin. Vai tr ch yu ca DCF l cung cp cc c chchuyn i thng tin. DCF c th cung cp cc chc nng nh tuyn, chuyntip v phi hp hot ng. DCF c th cung cp phng tin chuyn tithng tin lin quan n qun l vin thng gia cc khi chc nng qun l.DCF cung cp cc lp 1 n 3 trong m hnh chun OSI.

Hnh 2.3. Chc nng TMN

2.1.5.6. M hnh qun l TMN

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Cc b phnchc nng

TMNDCF

MCF MCF

Khi chc nng TMN Khi chc nng TMN

Cc b phnchc nng

TMN

Thng tin tng ng2 chiu

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CHNG 2

S LC V CNG NGH IP V MPLS

GII THIU

Nh ni chng trc, mng th h sau ca Cc Bu in Trung ngda trn nn tng cng ngh IP v MPLS do trong chng ny gii thiuv cc cng ngh tim nng nh IP, MPLS.

Tm hiu kin trc IP v tng th l hiu r nn tng ca c ch chuyn tipv nh tuyn, iu ny to nn mt c s su hn c th hiu r lm saocc b nh tuyn (Router) chuyn tip cc gi d liu thng qua mng IP vcch thc m chng s dng cc a ch.

Trong chng ny cng s trnh by tng i k v kin trc MPLS v sosnh n vi kin trc IP, bi v y l mt cng ngh kh mi. Thnh phniu khin giao tip vi cc Router khc to ra cc ng lin kt gia ccrouter trong mng. Cc ng lin kt ny c phn bit vi nhau bi mtnhn. Thnh phn chuyn tip c cc nhn trong tip u ca gi tinMPLS v chuyn gi tin n cc ng lin kt tng ng.

2.1. S LC V KIN TRC IP

Phn ny miu t v kin trc phn lp IP khi so snh vi m hnh by lpOSI - nh trong hnh 2-1. Cc thnh phn ca lp ng dng trong m hnhTCP/IP (Application layer) s c miu t trong hnh 2-2.

Hnh 2-1:So snh gia m hnh by lp OSI v kin trc ngn xp IP

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Mng Internet (v c ARPANET) c pht trin trc khi c m hnh OSIv cc kinh nghim thu c khi xy dng cc mng ny c nh hngquan trng n m hnh OSI.

Bi v kin trc tip u ca gi tin IP c chun ha vo cui th ktrc, rt nhiu dch v mi c pht trin cho nn tng ny. Hnh 1-2a ra miu t v kin trc ca gi tin chuyn mch IP.

Hnh 2-2:Kin trc IP vi v tr ca thng tin SNMP v ICMP

Khi xem xt cc ng dng hnh trn c th thy c mt s lin quan nmt lp thp hn lp ng dng, v d nh Ping, iu ny l gii ti sao lpng dng ca m hnh TCP/IP li m rng, nh trong hnh 2-1.

2.1.1. TNG QUAN V B NH TUYN

Chuyn tip cc gi tin ti cc a ch ch khc nhau c l l phn ct yunht ca mng Internet, trong khi nh tuyn l hnh ng chuyn ccthng tin qua mt lin mng (internetwork) t mt ngun ti mt ch. Theocch ny, t nht l truyn trong mt mng cc b, cn li cc gi tin thngc truyn t mng ny qua mng khc. Tin trnh thu nhn cc gi tin quacc mng khc nhau c thc hin bi cc Router.

Mt Router c th c xc nh nh l mt tp cc thit b m c dng lin kt cc mng d liu khc nhau. Trong nhng nm va qua Router

c b xung thm nhiu tnh nng mi. Chng c th c thm cc chc nngcao cp nh gim st lu lng, m c th c c bng cch s dng giaothc SNMP.

Router xc nh im mng k tip m gi tin cn i qua chuyn tip gitin n ch ca n. Router phi c kt ni vi t nht l hai mng khcnhau v xc nh a ch ch no nh tuyn mt gi tin bng cch ca ch ca gi tin. iu ny l gii ti sao router c t cng ra(gateway) ca mng.

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cc Router c th lin h vi nhau, IETF a ra chun RIP (RoutingInformation Protocol) chia x thng tin nh tuyn gia cc router vinhau. Giao thc RIP yu cu router gi ton b bng nh tuyn ca n ti

router ln cn theo chu k 30 giy. Tt c cc router c th c nh ngha chia x cc thng thin ny v tt c chng cp nht bn trong vng qun lca chng cng theo chu k 30 giy.

2.1.2. NH TUYN V CHUYN TIP IP

nh tuyn v chuyn tip c s khc nhau. Chuyn tip l qu trnh ly gitin t mt giao din v gi n ra trn mt u ra xc nh, trong khi nhtuyn l qu trnh xy dng ln cc bng m cho php cc u ra ng ca gitin c th c xc nh.

C hai phng php nh tuyn l nh tuyn trc tip v nh tuyn gin tip.nh tuyn gin tip l khi cc my ch phi gi d liu thng qua mt routerti mt mng khc, trong khi nh tuyn trc tip l khi cc my ch trongcng mt mng gi d liu cho nhau. Chng ta cng c nh tuyn tnh vnh tuyn ng. nh tuyn tnh l khi nh khai thc mng cu hnh cc bngchuyn tip ca router nhn cng. nh tuyn ng l khi cc router tnh tons mng t phn tiu ca gi tin v tm ra ng router k tip gi gi tinti. Phng n ny ch yu c dng nu cc my ch c cc a ch IPngu nhin.

hiu cng vic nh tuyn v chuyn tip c thc hin nh th no, hyxem xt m hnh c ba my tnh trong mt mng LAN nh, tt c u nm mt phn on a ch IP. Chng c a ch thuc lp C: 128.39.202.*, v do c th cho php ti 254 nt trn mng. Du sao * l mt s bt k t 0 n254. Mi mt giao din mng u c a ch MAC ring ca n (48 bit) , vd :4A-CE-87-44-4C-2A.

Hnh 2-3: Mt mng my tnh in hnh

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hnh 2-3, ta xem xt mt mng c 3 my ch (host). Nu my A mun gimt gi tin IP ti my tnh C thng qua Ethernet, A cn phi bit a ch IPca my C. Giao thc ARP ( Address Resolution Protocol) c s dng

khm ph ng cc a ch ny.nh tuyn trc tip l khi cc gi tin c gi trong cng mt mng bngcch s dng ARP. Mc nh ca ARP l cho php mi my ch trn mtmng to ra mt bng nh x gia cc a ch IP v a ch MAC. Ni cchkhc ARP gi mt bng a ch IP ni b v cc a ch Ethernet tng ng.

Nu module ARP khng bit a ch IP ca my C th n s pht qung b gitin trn mng v C s p ng li A vi a ch IP ca n, ARP s cp nht

bng d liu v bt u gi gi tin n a ch IP .

nh tuyn gin tip c s dng khi c mt Router ti cng ra (gateway)gia cc mng. Ch rng t gateway c th c cc ngha khc nhng tronglun vn ny ni miu t Router nh mt cnh ca i vo mt mng khc.Bng cch thm vo mt Router, iu ny c mt t trong hnh 2-4.

Hnh 2-4: Hai mng my tnh vi mt Router

Router R trong hnh 2-4 chuyn tip cc gi tin gia cc mng. lm iuny, n cn hai giao tip mng, mi giao din s nghe (listening) trn mimng. Nu A mun gi mt gi tin ti C, u tin n cn gi gi tin ti R, vti lt mnh R s chuyn tip gi tin ti C. iu ny c thc hin bngcch lm cho A s dng a ch Ethernet ca R m c th thu c bng cchs dng ARP v quan trng hn v a ch IP ca C.

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S dng bng nh tuyn c cu hnh nhn cng gi l nh tuyn tnh, tuynhin n yu cu rng cc giao tip mng c cc a ch IP c cu hnh tnhv n cng yu cu cc giao tip mng khng c chuyn khi mng ban

u. Nu phi chuyn mt my tnh ra khi mng th bng nh tuyn cnphi c cp nhp nhn cng.

nh tuyn ng s dng cc giao thc thng tin nh tuyn c bit tng cp nht bng nh tuyn vi cc router khc trong mng m c cu hnh chia x thng tin vi nhau. Cc giao thc ny c nhm li vi nhauthnh nhm cc giao thc IGP (Interior Gateway Protocol) hoc EGP(Exterior Gateway Protocol). Cc giao thc IGP c s dng phn bthng tin nh tuyn bn trong mt vng qun l (MD- Management Domain).

Mt vng qun l l mt tp cc router bn trong mt vng c qun tr bimt ngi c thm quyn. Cc v d ca giao thc IGP l OSPF (OpenShortest Path First) v RIP.

nh tuyn tnh c mt s u im khi so snh vi nh tuyn ng. u imc bn l kh nng d on c trc. Bi v nh khai thc mng tnh tonc bng nh tuyn, v ng i ca gi tin gia hai im ch lun lunc bit mt cch chnh xc v do c th c iu khin mt cch chnhxc, hn na bi v khng c giao thc nh tuyn ng no c s dng,

nh tuyn tnh khng bt cc router hoc cc lin kt mng chu thm bt kmt ti no na, nhng i vi mng c kch thc ln, bng tn ginh chovic cp nht s liu nh tuyn tng ln mt cch nhanh chng. Tng kt linh tuyn tnh d dng trin khai vi cc mng c kch thc nh. Nh khaithc mng n gin ch cn ni vi mi Router lm sao lin kt vi ttc cc phn on mng khc m n khng kt trc tip.

2.1.3. MT N MNG

Bng cch s dng php ton logic AND gia mt n mng (netmask) v ach IP, giao thc IP c th tnh ton xem liu a ch ch c th c gi timng ni b hoc thng qua mt gateway. Mi khi thit lp mt a ch IPcho mt giao tip mng th cng cn phi ch ra netmask. V d, trongWindows 2000a ch netmask mc nh l 255.255.255.0. Chng ta s khngi vo chi tit vic ny c thc hin th no v lm sao s hiu mng v shiu ca cc my ch tng ng vi a ch IP c tm thy.

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Hnh 2-5: Ba mng c kt ni vi nhau

Hn = Host, Rn = Router

Trong hnh 2-5 miu t ba mng c kt ni vi nhau s dng cc kiung kt ni khc nhau, nh Ethernet (ETH), Giao tip d liu quang phn

b (FDDI) v im -im (PPP). Cc router chuyn tip cc gi d liu TCPt H1 ti H8 nh miu t trong hnh 2-6. Nh ta thy cc gi tin IP c thc gi trn cc dng lin kt khc nhau v do l c lp vi lp lin kt.

Hnh 2-6 : Miu t giao thc no m cc lp s dng kt ni gia H1 tiH8 trong hnh 2-5. Ba router tng ng ba bc nhy t H1 ti H8.

Ch rng tt c tt c cc gi tin IP bao gm cc thng tin cho mngchuyn tip gi tin ti ch ca n v vic tm kim cc a ch s c thchin ti tt c cc router. Tuy nhin, do n khng c mt c ch thit lp thng bo cho mng phi lm g khi c gi tin n. Mt my ch gi cc gitin v mng s c gng mc cao nht (best-effort) chuyn chng ti chmong mun. Thut ng best-effort c ngha rng nu c li g xy ra v gitin b mt, mng s khng lm g c v n lm ht sc. Cc gi tin c thn khng ng theo trt t, hoc chng c th c truyn nhiu ln, iu

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ny lm cho cc giao thc lp cao hn phi lm thm mt s cng vic. Gicho cc router cng n gin cng tt l mt trong nhng mc tiu chnh camng IP.

2.1.4. CHUYN TIP KHUNG D LIU

Mt khung d liu c gi t mt my ch ngun ti mt my ch ch, cth thng qua mt vi router trn qung ng truyn a. Bt k mt nodeno d l my ch hay router, u tin c gng thit lp xem liu n c ckt ni ti cng mng vt l ca my ch. N thc hin iu ny bng cchs dng php ton AND gia netmask v a ch IP. Nu nt ca a ch chkhng c ni vi mng ni b, n cn phi gi khung d liu ti router.

Ni chunng, mi nt s c s la chn trong vi tuyn, v sau n chn citt nht hay t nht l c hi c th chuyn gi tin ti gn a ch ch hn.Cc router tm ng "hop"k tip bng cch tham kho trong bng chuyntip ca n. Bng chuyn tip v mt khi nim l mt danh sch cc cp nh miu t trong bng 2-1.

NetworkNum NextHop

1 R32 R1

Bng 2-1: V d v bng chuyn tip cho Router R2 trong hnh 2-5.

Trong hnh 2-5 chng ta c mt v d v bng chuyn tip ca Router R2. Ccrouter tm kim s hiu mng trong tip u gi tin, tm kim n trong bngchuyn tip v gi gi tin n "hop"k tip. gim khi lng thng tin, IPa ra h thng hai cp vi cc mng cp trn v cc nt cp di ca

bng.2.1.5. CC M RNG CA IPv6

IPv6 c mt nh dng tip u n gin hn so vi IPv4. Rt nhiu chcnng khng cn thit trong tip u ca IPv4 c b i i vi IPv6.iu ny dn ti kt qu l hiu nng ca Router c tng ln. im khcnhau cn bn gia hai phin bn IP l 16 byte a ch ngun v ch v cctrng ty chn trong phn tip u ca IPv4 c chuyn t vo phntip u m rng trong IPv6. Ngoi ra cng c th c rt nhiu tip u mrng khc trong IPv6. Cc tip y ny khi c mt trong IPv6 th phi c

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t theo mt trt t nht nh. Mt s n gin ha khc ca IPv6 so vi IPv4l phn tip u ca n lun lun c di c nh.

C phn tip u chnh (main-header) v phn tip u m rng ca IPv6 uc trng NextHeader. Trng ny bao gm mt th nhn dng kiu ca tipu m rng k tip. Sau phn tip u m rng cui cng l mt tip u calp chuyn vn (transport-layer) (v d: TCP) v trng NextHeader s baogm mt th nhn dng cho giao thc ca lp cao hn .

C su kiu tip u m rng trong IPv6 l:

o Hop-by-Hop Options

o Routing

o Fragment

o Destination Options

o Authentication

o Encapsulating Security Payload

KIN TRC MPLS V C CH CHUYN TIP CA N

2.1.6. KIN TRC MPLSMPLS l vit tt ca thut ng Chuyn mch nhn a giao thc (Multi-

Protocol Label Switching) trong t multi-protocolc ngha rng phngphp chuyn mch ny p dng c cho tt c cc giao thc lp mng chkhng phi l ch ring IP. MPLS c tc dng gn kt chuyn mch phi ktni IP (connectionless IP) ti cc mng hng kt ni (connection-orientednetworks). MPLS cng s hot ng o trn mi giao thc ca lp lin kt.

Nguyn l ca MPLS l tt c cc tin c ch nh mt nhn (label) v cc

gi tin c chuyn tip dc theo mt ng chuyn mch nhn (LabelSwitched Path-LSP) trong mi router trn ng i ca gi tin thc hincc quyt nh chuyn tip gi tin da trn ni dung ca nhn gn trn gi tin.Cc router c bng chuyn tip ca mnh, cc bng ny c ch mc hatheo gi tr ca nhn u vo (incoming label) . y l im khc bit so vic ch chuyn tip IP.

Cng ngh MPLS ng gp mt s a dng cc tnh cht mi cho kin trcmng cc lp thp. V d nh l m bo hiu nng mt cp nht nh

nh tuyn trong mt mng b nghn hoc to cc ng hm IPcho cc

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mng ring o da trn mt mng (network-based VPN). MPLS c kh nngto cc knh xuyn sut (end-to-end) tng t nh cc knh o (VirtualCircuit -VC) nh trong ATM. MPLS cng cung cp cc c tnh xc nh v

hiu nng nh x l lu lng (traffic engineering) trn bt k mt h tngtruyn thng no. Cc kh nng ny cho php gim s cn thit ca cc mngoverlay v cc c ch iu khin lp 2.

Thng thng chng ta thng c nhiu kinh nghim v giao thc lp lin ktca Ethernet nhng i vi cc giao thc khc nh ATM, FrameRelay th lic t hiu bit hn. Thc s l khng cn thit i su phn tch tt c cgiao thc lp lin kt m MPLS tng thch bi v trong lun vn ny chngta ch yu tp trung vo Ethernet, din gii thm v kh nng ca MPLS

ti s im s lc v thc hin MPLS trn ATM.Lp mng cung cp cho chng ta t la chn hn. Hin ti hu nh ch c ccti liu v IP/MPLS, mc d MPLS c th p dng cho tt c cc giao thclp mng khc nhau nhng trong lun vn ny ch miu t cng ngh ny trnkha cnh tng ng vi IP. L do l cc tiu chun quc t cng nh cc sn

phm thng mi ca cc nh cung cp thit b hu nh ch gii quyt cc giiphp da trn giao thc ny.

Kin trc ca MPLS c ch ra trong IETF RFC 3031. MPLS c thamkho n nh mt "Lp chm" (shim layer). Lp chm ny c ngharng nh trong hnh 1-7 th MPLS nm gia lp 2 v lp 3 khi quy chiu vim hnh OSI v v thc cht MPLS ch c tc dng lm cho cc lp ny gnkt nhun nhuyn vi nhau hn.

Hnh 2-7: So snh gia m hnh OSI vi TCP/IP v MPLS

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Khi nim c bn ca chuyn mch nhn thc s rt n gin. Hy ly mt vd v vic gi mt bc th in t t mt ngi dng n mt ngi khc,trong cc mng s dng cp dch v "best-effort" nh IP, th phng php

gi bc th ny n ch hon ton tng ng nh vic gi mt bc thqua Bu chnh vi gi thit l khng s dng m ZIP ca Bu cc nhn v

bc th ny c a ch nhn l duy nht. Cng vic y l xc nh a chch v a ra phng n lm sao gi bc th n ngi nhn cui cng.

i vi chuyn mch nhn th s vic c khc. Thay v vic dng ton b ach ch cung cp u vo cho cc router a ra quyt nh chuyn tip thch c mt nhn c gn vo gi tin. Tng t nh trong dch v Bu chnhth gi tr ca nhn c t vo ging nh m ZIP ca Bu cc nhn v phn

sau ca a ch nhn c s dng bi Bu cc nhn chuyn l th tingi nhn. Trong cc mng my tnh nhn c t phn tip u ca gitin v ton b gi tin IP tr thnh payload. Cc b nh tuyn by gi ch sdng nhn thay v s dng a ch IP nh hng lu lng v pha a chch (xem hnh 1-8).

Hnh 2-8: Hot ng ca MPLS

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Cc router c h tr MPLS c gi l Router chuyn mch nhn (LabelSwitch Routers-LSRs). LSR u vo (ingress LSR) l ni m gi tin i vomng MPLS. N thm tip u MPLS vo gi tin IP v gn thm mt nhn.

LSR u ra (egress LSR) l ni m gi tin IP ri khi mng MPLS v tipu MPLS c loi b khi gi tin. C LSR u vo v LSR u ra l ccnt bin (edge nodes) kt ni mng MPLS vi cc mng khc. Cc LSR qugiang (transit LSRs) cng cn c gi l LSR bn trong nhn gi tin t ccMPLS bin v s dng tip u MPLS to ra cc quyt nh chuyntip. N cng thc hin vic tro i nhn o (label swapping).

C hai c ch nh tuyn MPLS l : nh tuyn tng chng (hop by hop) vnh tuyn thng. Trong c ch nh tuyn tng chng, cc LSR to ra cc

ng chuyn mch nhn (Label Switch Paths-LSPs) t LSR u vo tiLSR u ra bng cch trao i thng tin vi nhau mt cch ngang hng. Ccthng tin trao i ny c lu trong bng nh tuyn ca LSR. Theo phng

php ny cc LSR to ra mt ng i hp l nht. Trong khi nh tuynthng c s khc bit nh ch ton b ng i hay mt phn ng i mcc LSR s dng i ngang qua mng t bin bn ny ti bn kia c nhngha thng bi LSR u vo v cc LSR s c xy dng da trn tuyn csn ny.

Khi cc LSR thc hin vic chuyn tip cc gi tin, n tch ly nhn hin tica gi tin MPLS ti mi mt hop v s dng n nh mt ch mc tmtrong trong bng chuyn tip ca n. Khi tm thy mt ch mc u vo tngng trong bng th LSR p dng nhn u ra cho ch mc ny i vi gi tinMPLS. Sau gi tin c gi qua giao tip c xc nh trong bngchuyn tip ca LSR. Cc gi tin MPLS thuc v mt LSP s c chuyntip theo cng mt cch bi tt c cc router trn LSP . Mt cch n ginvic chuyn tip v ch mc ha da trn cc bng chuyn tip s lm tng tc

x l chuyn tip bn trong mng MPLS v do ci thin c cc ctnh tr v trt ca lu lng.

MPLS cho php mt h thng cp bc cc nhn c bit n nh l mtngn xp nhn (label stack). V do n c kh nng c cc LSPs khc nhauti cc cp khc nhau ca ngn xp nhn. Tnh nng ny lm tng kh nngm rng ca LSP. N cng c th cho php t cc LSP nh cc LSP ln hn.i vi cc nhn theo h thng cp bc trng ngn xp (stack-field) ca tipu MPLS (c trnh by phn sau) c t l 1 nu nhn di

cng , v c t l 0 nu khng phi l di cng. Hnh 2-9 gii thchr hn v h thng cp bc ca nhn.

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Hnh 2-9: Mt v d v cp bc ca nhn trong MPLS

Cc router R1 v R5 thuc v hai LSP khc nhau. Cc s 1 v 2 l su cangn xp. R1 v R5 l cc router bin v R2, R3, R4 l cc router trong. Vimc ch l chuyn tip nhn th R1 v R5 l ngang hnh ti cp bin v R2,R3, R4 l ngang hng ti cp ni b. Khi R1 nhn c mt gi tin vinhn c su l 1 ch ti R5, n s tro i nhn ca gi tin bi mt nhntng ng m s c s dng bi R5. Cng bi v gi tin ny phi i quaR2, R3, R4 cho nn R1 s y vo gi tin thm mt nhn mi v do vy su ca ngn xp by gi l 2. Chnh v th chng ta thy c hai LSP, mtti cp 1 t R1 ti R5 v LSP th 2 t R2 ti R4.

Tip u MPLS c t gia tip u lp 2 v tip u lp 3. Mt v d vtip u lp 2 v lp 3 l Ethernet v IP. v tr ca tip u MPLS v nhdng ca n nh trong hnh 2-10.

Hnh 2-10: V tr v nh dng ca tip u MPLS.

Tip u MPLS di 32 bt v c bn trng. Tip u MPLS c ch ra hnh 11 v bao gm cc trng sau :

Trng nhn c di 20-bits cha gi tr thc ca nhn

MPLS. Cc gi tr t 0 n 15 c dnh cho cc chc nng c bitnhng ch mt s gi tr c nh ngha:

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o IPv4 Explicit NULL Label (value 0).

o Router Alert Label (value 1).

o

IPv6 Explicit NULL Label (value 2).o Implicit NULL Label (value 3).

o OAM Alert Label (value 14)

Trng Exp/QoS c di 3-bits l bn cht l mt trngc a ra da trn thc t gii quyt cc thut ton cho xp hng vhy b gi tin khi n c truyn qua mng.

Trng ngn xp c di 1-bit (trng S) xc nh y ca

ngn xp khi ngn xp c dng. S l "0" khi nhn khng phi y cangn xp v l "1" khi n y ca ngn xp.

Trng thi gian sng di 8 bit (time-to-live: T) l mt saochp ca trng TTL trong tip u ca gi tin IP n c tng ln khi gitin i qua mi chng.

Phng n "Lp chm " nh nu phn trn c s dng cho cc cng nghlp 2 m cc cng ngh ny khng th a cc nhn vo trong phn tip uca mnh. Cc cng ngh lp 2 ny ch yu l ch kiu kt ni ngoi tr

i vi ATM v FrameRelay. i vi ATM v Frame Relay, cc nhn ccha trong tip u lp lin kt ca chng. Trong ATM, nhn c th ccha trong trng VCI (virtual circuit identifier) hoc trng VPI (virtual

path identifier). Cng nh th, i vi Frame Relay, nhn c th c chatrong trng DLCI (Data Link Connection Identifiers) ca tip u FrameRelay.

2.1.7. THC HIN MPLS TRN ATM

Chng ta s xem xt vic thc hin ca MPLS trn ATM, nhng trc hthy tm hiu s lc v ATM.

Cc t bo ATM bao gm mt tip u c di 5 bytes v ti c di 48bytes. truyn mt thng tin c di ln hn 48 bytes c chuyn xungt cc lp trn, IP chng hn, thng thng ATM chia cc thng tin ny thnhcc phn nh hn, cng vic ny gi l phn mnh. Vic phn mnh thng tinc thc hin bi lp AAL (ATM Adaptation Layer ), lp ny nm gialp 2 v lp 3. Tip u AAL bao gm cc thng tin cn thit ni n ca

cc gi tin c th lp rp li cc thng tin b phn mnh.

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Mt n v d liu theo giao thc AAL5 (PDU) s c chia ra thnh ccphn c di 48 byte v cc on 48 bytes ny cng vi mt tip u ATM to thnh mt t bo ATM. Khi tt c cc t bo ATM thuc v mt PDU

n ch hoc n im cui ca mng ATM th chng s hp li vi nhauthnh mt PDU nh u vo.

Hnh 2-11: ng gi cc gi tinc gn nhn trn lin kt ATM

Khi mun s dng ng gi cc gi tin c gn nhn ca MPLS trn ATM,ton b ngn xp nhn s c cha trong AAL5 v nhn mc trn cng s

c cha trong trng VCI/VPI ca tip u ATM (xem hnh 12). L doca vic cha cc nhn trong c AAL5 PDU v tip u ATM ch yu l do su ty ca ngn xp. Khi cc t bo ATM n cui ca LSP chng sc rp li. Nu c nhiu nhn hn trong ngn xp nhn th AAL5 PDU sli c phn mnh v nhn m trn cng ca ngn xp nhn s c tvo trong trng VCI/VPI ca tip u ATM.

Cho n thi im ny chng ta thng s dng thut ng bng nh tuyn vbng chuyn tip (forwarding tables and routing tables) ch cc bng cha

cc thng tin tng ng cho vic nh tuyn v chuyn tip gi tin. Kin trcMPLS s dng cc tn khc cho cc bng ny: C s thng tin chuyn tipnhn (Label Forwarding Information Base- LFIB) v C s thng tin nhn(Label Information Base-LIB). LIB bao gm tt c cc thng tin nhn mLSR cn phi thu thp c t cc LSR ln cn ca n, theo kha cnh vhng i ca cc khung th LFIB s dng mt tp con cc nhn cha trongLIB cho chuyn tip gi tin hin ti.

L cn thit xc nh mt cch chnh xc cc gi tin no c nh x ti

mi LSP. iu ny c thc hin bi xc nh FEC (ForwardingEquivalency Class) cho mi LSP. FEC ch ra tp cc gi tin IP m c nh

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x ti LSP . Mi mt FEC c xc nh bi mt tp ca mt hay nhiuthnh phn FEC, trong mi thnh phn xc nh mt tp cc gi tin c thc nh x ti LSP tng ng. C mt vi kiu FEC thnh phn c nh

ngha ; thnh phn FEC a ch tip u l tip u a ch c di t 0 titon b di ca a ch. Mt a ch IP ph hp vi tip u a ch trongFEC l a ch IP c phn u ging tip u . Mt FEC thnh phn khc la ch my ch (Host Address). Thnh phn ny l a ch y ca mych. Cc nhn s c gn cho FEC trn ton b LSP. Nhn ny khng nthun ch ph thuc vo FEC m cn c th biu din cho t hp cc gi tinFEC v cc gi tin th hng u tin hoc cp dch v (CoS).

2.1.8. THNH PHN IU KHIN

Thnh phn iu khin c nhim v phn phi cc thng tin nh tuyn giacc LSR v cc th tc m cc router ny s dng chuyn cc thng tinny thnh cc bn tin nh dng LFIB. Cc bn tin LFIB s c s dng bicc thnh phn chuyn tip khi tin hnh chuyn tip cc khung tin MPLS.

C mt s tng ng kh ln gia thnh phn iu khin ca kin trcnh tuyn trc y v thnh phn iu khin ca chuyn mch nhn. Thnh

phn iu khin ca MPLS bao gm tt c cc tnh nng k tha t cc giaothc nh tuyn c dng trong thnh phn iu khin trc y nh OSPF,BGP v PIM. Theo ngha ny cc thnh phn iu khin ny to thnh mttp con ca thnh phn iu khin MPLS. thm vo cc th tc cn thitcn thiu mt LSR c th :

o To cc lin kt gia cc nhn v FEC.

o Thng bo ti cc LSR khc v lin kt m m n to ra.

o Tn dng c hai c ch trn xy dng v duy tr cc LFIB.

thc hin vic lin kt gia cc nhn v cc FEC c hai phng php.Kiu lin kt th nht c bit n nh l phng php lin kt cc b vch xy ra khi router to ra lin kt cho nhn u vo (incoming label) mtcch cc b. Kiu lin kt th hai l lin kt xa, khi router nhn c thngtin lin kt nhn t mt LSR khc v lin kt nhn c to bi LSR .

Thnh phn iu khin chuyn mch nhn dng c hai phng php lin ktcc b v lin kt xa nh v bng LFIB ca n vi cc nhn i vo v ira. thc hin c cng vic trn c hai cch tri ngc nhau:

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o Cc nhn t lin kt cc b tr thnh nhn i vo (ingoing labels) vcc nhn t lin kt xa c s dng nh cc nhn i ra - y llin kt nhn theo dng i xung (downstream label binding).

o Cc nhn t lin kt xa tr thnh nhn i vo v cc nhn t lin ktni b c dng nh l cc nhn i ra - y l lin kt nhn theodng i ln (upstream label binding).

gii thch thm v cc lin kt ny, cn phi hiu r thut ng dng ixung (downstream) v dng i ln (upstream) . Lung cc gi tin c gi tLSR ti ln (upstream LSR) v pha LSR ti xung (downstream LSR) - Xemhnh 2-12.

Hnh 2-12: Lin kt nhn dng i xung v i ln.

Hai phng php lin kt nhn khc nhau c gi tn tng ng vi ccLSR thc hin cng vic ti ln hay ti xung. Mt s lin kt nhn l nh xgia mt nhn cha trong gi tin v mt FEC c th m gi tin thuc v.Hnh 2-12 c minh ho hai kiu lin kt nhn. Trong kiu lin kt nhn dngti xung, cc nhn u ra trong bng chuyn tip c to bi LSR ti

xung, vi kiu lin kt nhn th hai, vic lin k c thc hin bi LSR tiln v do gi l lin kt nhn theo dng ti ln, nhn ny tr thnh nhnu vo trong bng chuyn tip.

Giao thc phn tn nhn (Label Distribution Protocol-LDP)l mt c chc bit n nhiu nht cho php cc LSR phn tn cc lin kt FEC ticc LDP ngang hng ca n. Nhng cng c mt s giao thc khc cho php

phn tn nhn nh BGP, PIM v RSVP. Trc khi hai LSR c th thc hinmt kt ni LDP, chng cn phi thc hin vic xc nh cc LSR ln cn.

Vic ny c lm theo cch LSR s pht theo chu k mt tin pht dng :Hello Message ti cng UDP ti tt c cc router trn subnet m thuc v

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nhm multicast. Tt c cc LSR nghe trn cng UDP ny v nh vic nhnc tin phtHello Message n nhn bit c cc LSR ln cn ca n. Khimt LSR bit c a ch ca mt LSR khc nh c ch ny, n thit lp

mt kt ni TCP ti LSR . Ti thi im ny mt phin lm vic LDP songphng c thit lp gia hai LSR.

Trc khi c th trao i cc nhn, th c mt phin khi ti LDP m cc LSRngang hng tha thun mi nhau ch trao i no c dng. C mt sch cho vic trao i cc lin kt nhn FEC. Hai ch la chn ch yul ti xung theo nhu cu (downstream-on-demand) v i ngc li l tixung t nguyn. Ti xung theo yu cu l khi LSR pht tn mt lin ktnhn FEC p ng li mt yu cu xc nh t mt LSR khc, trong khi

ti xung t nguyn l pht tn cc lin kt nhn m khng cn phi c yucu xc nh t bt k t mt LSR no.

Mt bn tin LR (Label Request Message) c s dng bi mt LSR ti lnnh kt qu ca vic pht hin mt FEC mi, xc nh mt cch r rng nyu cu LSR ti xung ch nh v bo li cho bit mt nhn cho FEC ny.LSR ti xung lun lun phi thc hin vic lin kt ny cho cc kt ni tiln. FEC c truyn ti LSR ti xung trong LRM. LSR nhn c bn tinLR phi p ng li vi bn tin LM (Label Mapping Message) vi mt nhn

x nh cho nhn c yu cu hoc vi mt bn tin thng bo xc nh rngti sao n khng th p ng c yu cu ny. Cc nhn ny ch c nghamt cch cc b, c ngha rng nhn ny ch c ch v c lin quan trn mtlin kt n l, gia cc LSR lin k. LSR ngang hng ti lt mnh li gimt bn tin LR ti LSR ngang hng ca n nu n cha c mt nh x notrong LIB ca n xc nh ng i ti chng k tip. Chng k tip (nexthop) l mt trng trong LFIB miu t router k tip chuyn tip cc gitin c gn nhn v pha LSR u ra (egress LSR). Cc router ny c

xc nh theo thuth ton tm ng i ngn nht hoc ng i c chi phthp nht . Bng cch nu trn LFIB c chuyn ti cc LSR trn mng.

Vic thit lp mt LSP m c trnh by phn trn hon ton c lp vivic thit lp iu khin LSP. Trong phng php th hai, thit lp mtiu khin LSP, LSR u vo v u ra khi to vic ci t LSP. Vic chnh nhn c iu khin theo mt cch c th t t LSR u ra ti LSR uvo ca LSP. l mt bn tin LR phi c gi ti mi LSR dc theong i ca gi tin t LSR ti ln ca LSP . Khng c mt lin kt nhn

no c th c ch nh trc kh bn tin ny n c LSR u ra. Bn tinLM by gi c th c gi theo ng c dnh sn v pha LSR u

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vo. Vi mi LSR trn ng i lin kt nhn c ch nh v c thmvo LFIB ca n.

Sau y chng ta s tm hiu LIB c pht tn trn MPLS nh th no. Nh nu trn LIB bao gm tt c cc thng tin nhn m LSR cn phi hc tcc LSR ti xung ln cn ca n c theo yu cu v t nguyn . Thng tinny c th l tip u a ch FEC (FEC Address Prefix), Nhn dng LSR lncn (Neighbor LSR Identifier), a ch IP ca cc LSR ln cn v cc lin ktcc FEC ti nhn. Bi v LIB cng bao gm thng tin khng bt buc, v vys c cc mc cha cc ng i khng phi l tt nht v s khng cdng cho vic chuyn tip gi in. LIB khng c dng nh x nhn uvo ti nhn u ra.

Cc phng php c trnh by trn y l cc thnh phn iu khin mcho php s thit lp trng thi chuyn tip d liu gia cc LSR lin k chda trn thng tin trong bng nh tuyn hoc t mt h thng iu khin.

Nhng cc phng php ny khng c kh nng thit lp trng thi chuyntip d liu ti tt cc LSRs dc theo mt tuyn xc nh v kh nng d trti nguyn dc theo mt tuyn. Cc iu ny v mt s tnh cht khc tothnh nn tng ca nh tuyn cng bc. C hai phng php t ccc LSP da trn cng bc l : RSVP xp t lu lng (RSVP Traffic

Engineering :RSVP-TE) v LDP nh tuyn cng bc (CR-LDP). Cc giaothc bo hiu ny cho php MPLS iu khin ng i ca mt gi tin bngcch xc nh r rng cc router trung gian v tuyn truyn c tnh ton timt thi im ti mt im bin ca mng. Cc cng vic theo cch nyc thc hin kh ging nhau trong c hai c ch v vy sau y s ch trnh

by thm v phng php CR-LDP.

CR-LDP s dng bn tin LR trong LDP thit lp vic nh tuyn cngbc, trong LDP c m rng vi cc gi tr di kiu (Type-length-

values :TLVs) mi thm vo so vi cc LDP TLVs chung. TLV l mt bnmiu t i tng c dng trong mt vi giao thc. cc TLV cho LDP miny c gi l cc TLV nh tuyn cng bc (Constrained-based RoutingTLVs :CR-TLV). Khi mt LSR mun to mt CR-LSP, bn tin LR phi chat nht l LSPID TLV v cng c th cha mt hoc nhiu CR-TLV trongtrng cc gi tr ty chn ca n. LSPID TLV cung cp cho CR-LDP mtc tnh xc n m c th c s dng sa i LSP. Khi s dng CR-LDP n c th xc nh mt cch r rng vic nh tuyn v ti nguyn no s

c cp khi LSP c thit lp.

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2.1.9. THNH PHN CHUYN TIP

Hnh 2-13: Cu trc ca LFIB

Thnh phn chuyn tip lit k cc mc ca LFIB tm ra cch lm saochuyn tip cc khung MPLS i vo ti LSR k tip. LFIB nh miu t

phn trn c pht tn b thnh phn iu khin.

LFIB ca mt LSR bao gm cc mc theo tun t, trong mi mc bao gmmt nhn u vo v mt hoc nhiu mc con. Mi mc con bao gm mtnhn u ra, mt giao din u ra v a ch chng k tip (xem hnh 2-14).Cc mc con khc nhau trong mt mc chnh li c th c nhiu hn mt mccon na iu khin vic chuyn tip ti nhiu a ch. Hn na i vithng tin iu khin gi tin s c chuyn tip ti u, mt mc trong

bng chuyn tip c th bao gm thng tin lin quan ti cc ti nguyn nom gi tin c th c s dng. Thng tin ny v d nh l hng i u ra

c bit no m gi tin c xp vo.Mt LSR c th ch duy tr mt bng chuyn tip n hay cho mi giao tipca mnh n li c mt bng chuyn tip ring. Vi kh nng th nht, viciu khin mt gi tin c xc nh n thun ch bi nhn c cha tronggi tin . Trong khi vi la chn th hai, iu khin gi tin c xc nh

bi khng ch bi nhn cha trong gi tinm cn bi giao tip m trn gitin ti . Mt LSR c th s dng la chn mt hoc hai hoc mt t hp chai.

Mt tnh cht quan trng ca thut ton chuyn tip c dng bi chuynmch nhn l mt LSR c th nhn c tt c cc thng tin cn thit chuyn tip gi tin cng nh quyt nh xemti nguyn no m gi tin cth dng ch trong mt ln truy nhp b nh duy nht, bi v cc l do sau :

a) Mt mc d liu trong bng chuyn tip bao gm tt c cc thng tincn chuyn tip gi tin cng nh quyt nh ti nguyn no m gitin c dng.

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b) Nhn c cha trong gi tin cung cp ch mc tm mc d liutng ng trong bng chuyn tip s dng cho vic chuyn tip gi tinny.

Kh nng nhn c c thng tin chuyn tip v thng tin v ti nguyndnh cho gi tin trong mt ln truy nhp b nh lm cho chuyn mchnhn tr thnh mt cng ngh c tc chuyn tip d liu cao so vi cccng ngh trc n.

2.1.10.V D V NH TUYN TRONG MPLS

Mt v d v nh tuyn d liu trong MPLS minh ha hot ng c bn caMPLS khi nh tuyn. Bng cch s dng cc giao thc nh tuyn IP quy

c v LDP cc LSR to nn cc bng nh tuyn c b xung thm vi ccnhn c gi l cc LIBs . Trong hnh 2-14 cc nt mng A, B, C, v D lcc my ch khng c cu hnh vi MPLS, LSR1 l LSR u vo, LSR2 lLSR qu giang v LSR3 l LSR u ra.

Hnh 2-14: Tro i nhn v chuyn tip trong MPLS

LSR1 trong hnh 2-14 nhn mt gi tin IP t nt A trn giao tip 0,c xc

nh a ch gi n l nt C . LSR1 l LSR u vo v n thc hin vic tmkim mc ph hp c di nht gia a ch ch trong gi tin Ip v cc tipu trong trong LIB ca n. Cc th tc lin kt FEC ti nhn trong LIB can cng c thc hin. Theo cch ny nhn ban u cho gi tin IP c tmthy v tip u ca nhn c ng gi vo gi tin IP. Cc c tnh chuyntip khc nh router chng tip theo v giao tip i ra c tm trong LFIBca LSR1. Gi tin c gn nhn s wocj chuyn vi nhn 3 ti LSRchng tip theo (l LSR2) trn giao tip

u ra s 2.

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Khi LSR2 nhn c gi tin n ch x l phn tip u nhn. N tch lynhn v s dng gi tr ly c tm kim ch mc theo ct nhn vo (labelIN column) trong LFIB ca n. N tm thy nhn u ra tng ng cho nhn

u vo 3 l "7" v n thc hin thay th nhn u vo ny bng gi tr canhn u ra trong phn tip u nhn sau chuyn tip gi tin ti LSR3 trngiao tip 2. y chnh l vic chuyn mch nhn .

LSR u ra cng ch thc hin vic x l i vi tip u nhn v tm kimnhn u vo trong LFIB ca n. LSR3 pht hin rng n l u ra ca LSPv router chng k tip li chnh l n v vy n b tip u nhn ra khi gitin n. Phn cn li ca gi tin chnh l gi tin u vo ca LSR1 nhn vc chuyn tip nt C qua giao tip 2.

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CHNG 3MT S CNG NGH QUN L MNG P

DNG TRONG MNG IP V MPLS

3.1. GII THIU

Trong chng ny chng ta s i su phn loi mt s chc nng v vn hnh

v bo dng (Operation And Management - OAM) c hoc c xutcho IP v MPLS.

Trc ht, chng ta s m t v mt c ch qun l mng c th c s dngcho c cc mng IP v MPLS. V nh ngha qun l mng l mt gii php gim st v kim tra mng li pht hin li. Giao thc qun l mngn gin (Simple Network Management Protocol - SNMP) c pht trincho mc ch ny . SNMP c dng nhn cc thng tin t cc Router

bng cch truy nhp vo cc MIB (Management Information Bases) khc

nhau ca chng cc nt trn mng.Tip theo, mt s phn loi cc c ch OAM cho IP v MPLS s c trnh

by. Bn thn IP khng c mt c ch no kiu nh vy, nhng cc m rngca IP nh ICMP (Internet Control Message Protocol), Ping, Traceroute vMIBs l cc chc nng chnh c s dng cho cng ngh ny. Ngc liMPLS c cc phng n cho rt nhiu c ch OAM khc nhau.C ch xcminh kt ni LSP cho php pht hin cc li khc nhau trn cc LSP v xut mt s cc nh dng gi tin khc nhau. MPLS ping, Traceroute v pht

hin nt li - RSVP l cc phng php khc pht hin li. Chuyn mchbo v v ti nh tuyn nhanh cho php vic truyn a gi tin qua mngmt cc tin cy, trong khi x l lu lng MPLS v MPLS SNMP MIB lcc c ch thay th khc cho php gim st mng mt cch hiu qu.

3.2. QUN L MNG

3.2.1. KIN TRC QUN L MNG

Trong mt h thng qun l mng c hai thnh phn chnh l my ch qun l(Manager) v cc tc nhn (Agents). My ch qun l c hai chc nngchnh: thu thp v hin th trc quan thng tin. N thu thp thng tin t cc

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tc nhn v s dng cc c ch khc nhau xp xp v nht ra cc d liu clin quan. Cc tc nhn c trch nhim truyn a thng tin v phn cnghoc phn mm. Mt cch tng th, cc tc nhn c dng cho mc ch

lm tc v nh gim st s dng lu lng, tnh trng ca cc thnh phnc ni vo mng v cc hot ng tng t.

Hnh 3.1. Kin trc mt h thng qun l mng

Nh hnh 3.1, h thng qun l mng NMS (Network Management System)lin h vi cc thit b khc nhau trn mng v nhn cc thng tin MIB(Management Information Bases) t cc tc nhn SNMP ca cc thit b ny.

3.2.2. SNMPc pht trin t nm 1998, SNMP tr thnh phng n chung cho vicgim st cc mng IP. SNMP c kh nng m rng, cho php cc nh cungcp thit b khc nhau d dng thm cc chc nng qun l mng vo trongcc thit b hin c ca h. SNMP chy trn cng ca giao thc UDP.

Chin lc ngm trong SNMP l gim st cc trng thi ca mng ti bt kmt cp c ngha no v mt chi tit bng cch kim sot theo kiu xoayvng tm kim cc thng tin ng ra c cc gii php qun l tt nht

c th. Mt s lng gii hn cc bn tin c pht i mt cch ch ng(traps) xc nh thi im v tiu im ca vic kim sot xoay vng. Vicgii hn s lng cc bn tin ch ng pht i nhm nht qun mc tiu lmn gin v ti thiu ho lu lng truyn trn mng to ra bi cc chc nngqun l mng.

Ni mt cch khc SNMP l mt tp cc cc quy tc m lm cho cc thit bphn cng nh l my tnh v router c th d theo theo cc thng k khcnhau cho php o cc c im quan trng nh s gi tin nhn trn mtgiao tip. Cc thng tin khc nhau m SNMP nhn c c lu trong cc

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c s d liu khc nhau, c gi l MIB (Management Information Base).SNMP l mt giao thc lp ng dng v c dng gn nh ch dnh ringcho cc mng TCP/IP.

3.2.2.1. Kin trc MIB

C tng i nhiu cc dng MIB khc nhau, cho rt nhiu cc kha cnhkhc nhau ca vic vn hnh mng cng nh th hin cc loi thit b khcnhau. Khi s dng SNMP c th kt ni ti cc MIB ny, nh v cc bin caMIB v gi ra cc gi ny cng nh sa i chng. cc bin ca MIB cnh ngha bi mt th xc nh i tng (Object Identifier-OID) m thc ral mt h thng a ch c cp bc, nh mt h thng dch v tn vng DNS(Domain Name Service) . OID s dung mt h thng cc s, trong s utin l gc ca h thng cp bc v s th hai l nhnh, v..v.. . Hy xem v ddi y, a ch ca MIB sysDescr l 1.3.6.1.2.1.1.1. Din dch ra nh sau :

.iso(1).org(3).dod(6).internet(1).mgmt(2).mib(1).system(1).sysDescr(1).

Ta c th thy gc y l ISO v cc i tng con c xc nh theong s ca n. Hnh 3.2 m t r hn v vn ny:

Hnh 3.2. Cy OID

Ngy nay SNMP trn cc thit b mng ang tr thnh mt yu cu gn nhbt buc. Internet l mt trong nhng ng dng n l s dng SNMP. SNMPqua UDP/IP c xc nh nh l mt giao thc ca tiu chun Internet("Internet Standard" protocol). Do , c th c vn hnh qua Internetv qun l c th mt thit b phi h tr SNMP qua UDP/IP.

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3.2.2.2. An ninh mng

truy nhp ti cc tc nhn SNMP, SNMP s dng phng thc Yu culy (Get-Request) v s c chp nhn hoc b t chi ty theo mt khum n dng truy nhp ng hay sai. Mt khu ny c nh ngha nh lmt chui nhm ch c (Read-only Community String). Thng thng, mtkhu mc nh l cng cng. Cc nh khai thc thng thay i mt khu mcnh thnh chui nhm ch c gi cc thng tin ny ch ring cho cc nhvn hnh mng. Ta cng c th nh ngha b lc IP, i vi mt s thit b,cho kt ni SNM ci thin an ton cho mng.

Ngoi ra SNMP cng dng phng thc yu cu thit lp (Set-Request) thit lp hoc thay th mt s bin ca MIB thnh mt gi tr xc nh. Ccyu cu thit lp ny c bo v bi chui nhm ch vit (Write CommunityString).

SNMP cng nh ngha by li SNMP, n l mt ngtt mt thit b ti mtbn giao tip SNMP v trng thi ca thit b. Cc by li c th xc nhng lin kt tt/xu v thng bo v tnh trng ca ngun cung cp. Cc

by li ny ci thin kh nng thu nhn s liu ca SNMP, bi v mt s byli khng c pht hin khi h thng NMS gi yu cu SNMP theo mt chuk nht nh.

3.2.3. OAM TRN IP

cung cp chc nng OAM trn IP nh khai thc h thng c th s dngcc phn mm khc nhau hoc cc kch bn dng sn gim st mng. Ccgii php v phn mm yu cu thng tin t cc router v cc switch bngcch s dng cc lnh ping, traceroute v SNMP. SNMP c th kt ni ti ccloi MIB khc nhau m bao gm cc thng tin nh ti ca b x l, ti lulng, v..v...

Hnh 3.3. OAM trn IP

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My tnh trn hnh 3.3 thu thp cc thng tin v lu tr cc thng tin nytheo mt chu k nht nh. Cc thng tin ny l u vo cho cc tin trnh xl pht hin li hoc cc bt thng trn mng.

3.2.3.1. Ping v ICMP

Mt c ch ph dng nht c s dng xc nh xem cc router hoc ccnt trn mng c th kt ni c khng l s dng lnh Ping. Ping o tr haichiu gia ngun v ch.Ta cng c th xc nh thi gian p ng ca cch thng khc nhau bng cch s dng chng trnh nh ny. N s dng cctrng ICMP xc nh cc gi tr li tng ng:

Mt s trng ICMP

Kiu

3

M

0 = Mng khng ti c

1 = Host khng ti c;

2 = Giao thc khng ti c;3 = Cng khng ti c;

5 = Tuyn ngun b li.

Kiu

8 cho bn tin echo;

0 cho bn tin p ng echo.

M

0

Bng 3.1: Bn tin ICMP khng ti c ch (type3) v bn tin ICMP Echo(Reply Message)

ICMP l mt giao thc iu khin bn tin v bo co li m hot ng giathit b mng v cng vo. N s dng cc khung tin v thc t n l mt

phn ca gi tin IP (xem hnh 2.2). Cc bn tin c gi li my ch c yucu, v khng c iu chnh bi cc routers. l cch tt nht xemliu cc thit b trn mng c on-line hay khng.

ICMP c rt nhiu cc bn tin li m c th xc nh c my ch l :

o Khng th kt ni ti c(c th bi v kt ni b li).

o Qu trnh ghp li cc gi tin b li.

o Thi gian sng ca gi tin (TTL) t gi tr 0.

o Tng kim tra tip u IP b li.

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o .....

C mt s kiu bn tin ICMP l :

0 - Echo Reply.3 - Destination Unreachable

4 - Source Quench.

5 - Redirect.

8 - Echo

11 - Time Exceeded

12 - Parameter Problem

13 - Timestamp)

14 - Timestamp Reply

15 - Information Request

16 - Information Reply

Tt c chng u c chc nng xc nh xc nh cc li v s ln p ng.

3.2.3.2. IP MIB

Bi v cc nt mng m chng ta cn phi d theo xc nh trng thi cphn tn, ty chn duy nht ca chng ta l s dng mng qun l mng.iu ny c ngha l chng ta cn mt giao thc cho php chng ta c v cvit cc thng tin trng thi trn cc nt mng khc nhau.

Cc bin MIB thng thng ch duy tr cc thng tin v phn cng xc nhcho mt thit b theo yu cu. Cc hng sn xut c mt lat cc thng tin mc th c gim st cho cc thit b ca h.

Mt s bin MIB tiu biu l:o sysUpTime : bin h thng cha thi gian k t ln h thng c

khi ng li ln cui cng.

o ifNumber: bin giao tip cha s giao din mng.

o ipDefaultTTL : bin IP cha gi tr thi gian sng mc nh .

o ipInReceives: s gi tin nhn c.

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3.2.3.3. Cc chc nng OAM mi trong IPv6

Trong IPv6 h tr cho vic t ng cu hnh a ch cc my ch v ccrouters. C hai kiu t ng cu hnh a ch :phi trng thi (Stateless) and ctrng thi (stateful). Phng php phi trng thi c s dng khi mt sitekhng quan h c bit vi chnh xc cc a ch cc my ch c dng, vv vy chng l duy nht v c kh nng nh tuyn ng. Phng php nhtuyn c trng thi c dng khi mt site yu cu s iu khin cht ch hnthng qua cc s ch nh a ch chnh xc. c hai phng thc t ng cuhnh a ch trn c th c s dng ng thi.

T ng cu hnh phi trng thi khng yu cu bt k mt s cu hnh nhncng cc my ch no, ti thiu (nu c) s cu hnh cc router. C ch phitrng thi cho php my ch to ra cc a ch ca ring n bng cch s dngmt t hp thng tin cc b v thng tin c cung cp bi cc router. Ccrouter cung cp cc tip u xc nh cc subnet lin kt vi mt kt ni,trong khi my ch to ra mt "Th nhn dng giao tip", th ny l nhndng duy nht cho mt giao tip trn mt. Mt a ch c to ra trn c st hp c hai. Nhng trc khi mt a ch cc b mi c s dng, mych phi m chc rng khng c my ch no khc ang s dng a chny.

Trong m hnh t ng cu hnh c trng thi, cc my ch nhn cc a chca cc giao tip v/hoc thng tin cu hnh v cc tham s t mt my phcv khc . Cc my phc v duy tr mt c s d liu bm theo cc a ch c cp cho cc my ch.

3.2.4. OAM TRN MPLS

3.2.4.1 Tng quan cc cng vic hin ti

Cng vic ang c trin khai v OAM trn MPLS mi ch dng ch yu

mc bn tho ch cha phi l cc khuyn ngh hoc cc tiu chun. ITU-T xut bn bn d tho Cc yu cu v chc nng OAM cho cc mng MPLScung cp cc y nn tng chc nn

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