Nghiên cứu vấn đề điều khiển lưu lượng trong mpls

Danh muc cac hinh Hinh 7.1 Mgng lot core MPLS Hinh 7.2 Mot vi du ve dinh tuyen rdng budc Hinh 7.3 Tdc nghen gdy ra bdi ky thuat chon dudng ngdn nhdt Hinh 7.4 Gidi phdp cho vdn de sir

DAI HOC QUOC GIA HA NOI

Chu nhiem de tai: Ths Pham Thj Hong

DAI HOC Ql.OC GIA HA NCI TRUNb lAfvi IHOIMG TIN I H U VIEN OOO6000004^

Hanoi 2010

1 MUC LUC

1 Muc luc 1

2 Bang giai thich cac chu viet tat 2

3 Danh sach nhihig nguoi tham gia thuc hien de tai 7

4 Danh muc cac bang so lieu g

5 Danh muc cac hinh

.X , ,

8

6 Tom tat cac ket qua nghien cuu chinh cua de tai q

7 BAG CAO TONG KET

7.L Dat van de

7.2 Tong quan cac van de nghien cuu

7.3 Muc tieu va Noi dung Nghien cuu cua De tai

7.4 Dja diem, thoi gian va phuang phap nghien ciru

7.5 Ket qua nghien cuu

7.6 Thao luan

7.7 Ket luan va kien nghi

7.8 Tai Heu tham khao

10

10

2 Bang giai thich cac chu' vi§t tat:

AS Autonomous System

ATM Asynchronous Transfer Mode

BGP Border Gateway Protocol

BTT Bidirectional Traffic Trunk

CR- Constraint Routing Label Distribution

LDP Protocol

CSPF Constraint Shortest Path First

DS Differentiated Services

DSCP DS Code Point

DiffServ Differentiated Services

EGP Exterior Gateway Protocol

L-LSP EXP-Inferred-PSC LSP

FEC Forwarding Equi\'alence Class

FF Fixed Filter

FR Frame Relay

IETF Internet Engineering Task Force

IGP Interior Gatew a> Protocol

ILM Incoming Label Map

IP Internet Protocol

IPOA IP over ATM

lntSer\ Integrated Ser\ ices

IS-IS Intermediate S>stem-Intermediate

He tu tri Che dp truyen khong ddng bp Giao thuc Cong bien gidi Luu lupng 2 chieu trung ke Giao thuc phan phoi nhan gidi han tuyen

Gidi ban Cac dich vu phan biet Diem ma hda DS Cac dich vu dupc phan biet Giao thi'rc cong Ext

l u ) e n chu)en mach nhan EXP Ldp chuyen tiep tuong duong Lpc dupe CO dinh

Khung Relay Lyc lirang kiem soat cdng nghe Intem Giao thuc edng Int

Anh xa nhan loi \ ao Giao thi'rc Internet

Cac dich \ u tieh hpp

I le thong tuc ihdi

Internet Service Provider

Label Distribution Protocol

Label-only-inferred-PSC LSP

Label Switching Path

Label Switching Router

Next Hop Label Forwarding

Entry

Multi-Field

Multi Protocol Label Switching

Open Shortest Path First

Per-hop Behavior

PHB Scheduling Class

Quality of Service

Routing Information Protocol

Resource Reservation Protocol

Virtual Circuit Identifier

Virtual Path Identifier

He thdng tiic thdi

Nha cung cap dich vu Internet

Giao thtic phan phdi nhan

Nhan LSP

Tuyen chuyen mach nhan Router chuyen mach nhan Ldi vao chuyen tiep nhan Hop tiep theo

Da trudng Chuyen mach nhan da giao thuc

Tuyen ngan nhat

Ldp lap lich PHB Chat lupng dich vu

Giao thuc thdng tin tuyen

Giao thuc dy trir tai nguyen

Chia xe Giao thuc dieu khien truyen tin

3 Danh sach nhirng nguai tham gia thyc hien de tai (hoc ham, hoc vi, co quan cong tai

• Chu tri de tai :

Ho vd ten : Pham Thi Hdng Nam Z , nit- ~

Ndm sinh: 1/1981

Chuyen mdn ddo tgo : Dien tu - Vien thdng

Hoc hdm, hgc vi: Thgc sT

Chirc vu: Cdn bd gidng day tgi bd mdn He thdng Vien thdng

Ca quan cdng tdc : Khoa Dien tie Vien thdng Tnrdng Dgi hoc Cdng nghe

• Cac can bo tham gia

Co quan cong tac Dai hpc Cong nghe DHQl

Ha noi Nguyen Qudc Tuan

Bui Truna Ninh

I hon a

Dai hpc Cong nghe DHQ(

Ha noi Dai hpc Cong nghe DHQI

Ha noi Dai hpc Cong nghe DHQI

Ha noi

4 Danh muc cac bang so lieu

5 Danh muc cac hinh

Hinh 7.1 Mgng lot (core) MPLS

Hinh 7.2 Mot vi du ve dinh tuyen rdng budc

Hinh 7.3 Tdc nghen gdy ra bdi ky thuat chon dudng ngdn nhdt

Hinh 7.4 Gidi phdp cho vdn de sir dung ky thudt liru lugng

: Thii tuc khdi phuc mgng 2'tuyen

.• Md hinh todn hoc cua mgng 2 tuyen

.• Mo hinh 3D MDP khoi phuc mgng

.• Trgng thdi dich chuyen Markov (0, 0, 0)

." Trgng thdi dich chuyen Markov (0, x2, 0)

Hinh 7.10 : Trgng thdi dich chuyen Markov (0,M, 0)

Hinh 7.11 : Trgng thdi dich chuyen Markov (xl, 0,0) 19

Hinh 7.12 : Trgng thdi dich chuyen Markov (M, 0, 0) 19

Hinh 7.13 : Trgng thdi dich chuyen Markov (xl, x2, 0), khi xl+ x2 < M 20

Hinh 7.14: Thiet lap tuyen ngugc 23

Hinh 7.15: Phdt hien loi tuyen 23 Hinh 7.16: Thiet lap tuyen du phdng 25

Hinh 7,17 : Dinh tuyen lgi 25

6 Tom tSt cac ket qua nghien cuu chinh cua de tai

6.1 Ket qua khoa hoc

• 02 bao cao khoa hpc tai cic hpi nghi Quoc te to chuc trong nudc

6.2 Ket qua Crng dung

• San pham cdng nghe:

Chua cd

• Kha n i n g ung dung thuc te ciia cac ket qua:

- Cho cac mang NGN

- Cho cac mang khdng day the he 3,5G khac (HSDPA)

6.3 Ket qua dao tao

• San pham dao tao

• Dai hpc: 02 khda luan tot nghiep sinh vien Dai hpc chat lupng cao

• Bo xung tai lieu eho giao trinh

- Bd xung mpt phan kien thuc cho giao trinh giang day Dai hpc lien quan den mang NGN

6.4 Ket qua ve tang cw&ng item IIFC cho dan vj

• Ket qua bdi dirdng cdn bd: Giup cac can bp tang cudng kha nang nghien cuu tii

can cac phuong phap nghien cuu cac giao thuc mang mdi dya tren mo phong

• D6ng gop cho \"iec tang cudng trang thiet bj:

Khong nhieu

7 BAO CAO TONG KET

7.1 Dat van de

May nam gan day, cung vdi sy phit trien cua cic cdng nghe mang, ngudi

ta mdi nhan thay rd rang la mang vien thdng, mang may tinh deu mong mudn

su dung cac dich vu dya tren IP Cac dich vy dya tren IP (chu yeu la cac dich vu Internet, dich vu gia tri gia tang ) la cac dich vu phd bien ca sd deu cd the thyc hien noi thdng cic mang khic nhau;

Giao thuc IP thyc te da trd thanh giao thuc mang cho Internet nhung giao

thiic nay tdn tai nhiing nhupc diem cd hiiu cua nd nhu i) khdng ddm bdo chdt lugng dich vu vi ban than nd la giao thiic truyen khdng lien ket va ii) tdc do chuyen tiep tin thdp do phai xii If tieu de Idp mang nham djnh tuyen - tim tuyen

ndi tdi tram dich

Sy phat trien cua mang vien thong can phai dinh tuyen va chuyen mach toe

dp cao cho cac dich vu dya tren IP nham dam bao bang thdng trong mang loi de truyen du lieu, thoai va video vdi QoS chap nhan dupc Chinh nhirng dieu dd da lam cac nha quan tn mang da va dang tim mpt phuong thiic chuyen mach cd the phoi hop uu diem cua IP va ATM de dap ling nhu cau phat trien cua mang ludi trong giai doan tiep theo, trong do cd viec nghien ciiu cong nghe chuyen mach nhan MPLS

Cdng nghe MPLS la ket qua phit trien cua cdng nghe chuyen mach IP dung CO che hoan doi nhan nhu cua ATM de tang tdc dp truyen gdi tin ma khdng can thay doi cac giao thiic dinh tuyen cua IP MPLS tach chiic nang cua IP thanh hai phan rieng biet: chiic nang chuyen gdi tin va chiic nang dilu khiln Ben canh

su-do, MPLS cung hd trp viec quan ly de dang ban

Trong nhiing nam gan day, MPLS da dupc lya chpn dl don gian boa va tich hop mang trong mang Idi Nd cho phep cac nha khai thac giam chi phi, don gian hoa viec quan ly luu lupng va hd trp cic djch vu Internet Quan trpng hon ca,

nd la mpt budc tien mdi trong viec dat muc tieu cho NGN vdi cic dich vu thoai, dii lieu vahinh anh

7.2 T d n g q u a n cac v i n d§ n g h i e n CLFU

MPLS la cong nghe thudng dung trong mang loi (core), bdi vi trong mang core la

ma mpi du lieu se dupc dinh tuy^n va chuyen mach va truyen dan tdi mang khac vdi tO( cao nhit, dim bao QoS theo yeu cau dich vu, vi vay mang core chiu mpt tai trpng rat ldn chi su dung cac cdng nghe binh thudng, chi cd mang MPLS cd the dap ling dupc cac yeu khac khe tren

Bo dmh luyen chuyen rnaih nhan loi iCon; LSRl

Wnh 7.1 Miin^ loi (core) MPLS

MPLS ho trp tat ca cac giao thiic dinh tuyen (tinh IGP EGP) Nhung de tri^n khai thuat luu lupng can biet dupe cac thong so tai nguyen mang dieu nay chi dupc thuc hi tren cac giao thiic Link State (OSPF IS-IS)

Mpt cai tiln quan trpng cua MPLS trong ky thuat luu lupng la hd trp "dinh tuyen ra

buoc" Vdi dinh tuvin rang buoc, vin dh su dung tai nguyen va phan phdi luu lupng tro!

mang dupe tdi uu Thue chit "dinh tu>Cm rang buoc" dupe nang cao tir cac giao thuc dn

ixxyin thong thudng Qua trinh thyc hien dinh tu> C^n rang buoc gdm 2 budc:

• Budc 1: boat dpng cua cac giao thuc dinh lu_\in

• Budc 2: qua trinh tinh loan thiet lap tu\en diinu CSPF

7.2.1 Dinh tuyen rang buoc

7.2.1 Djnh tuyen rang buoc

Dinh tuyen rang budc la mpt phuang tien de thyc hien xii Iy ty dpng hoa

ky thuat luu luang, khac phuc duac cac han che cua dinh tuyen theo dich Nd xac dinh cic route khdng chi dua tren topo mang ma cdn sii dung cac metric die thu khac nhu bang thdng, tre, cost va bien dpng tre Giai thuat chpn dudng cd khi nang toi uu hda theo mpt hoac nhieu metric nay, thdng thudng ngudi ta dung metric dya tren sd bop va bang thdng, Chpn dudng ngan nhat trong so tat ca cac dudng cd bang thdng kha dung thoa man yeu cau

600 Kbps ->- 300 Kbps

•>• 200 Kbps

Egress Kot-ter

Kenh 1 Mbpi

Hinh 7.2 Mot vi du ve dinh tuyen rang buoc

Dinh tuyen rang budc cd 2 kieu online va offline Kieu online cho phep cac router tinh dudng cho cac LSP bat ki luc nao Trong kieu offline, mpt server tinh dudng cho cac LSP theo dinh ki ( chu ki cd the dyoc chpn bdi nha quan tri, thudng la vai gid hoac vai ngay ) Cic LSP dupc bao hieu thiet lap theo cic dudng da chpn

7.2.2 Djnh tuyen tucmg minh

Dinh tuyen tudng minh la tap con ciia dinh tuyen rang budc, trong dd sy rang budc la ddi tugng tudng minh Tuyen tudng minh ER la mpt danh sach cic mit triru tupng m i mpt dudng chuyen mach nhan rang budc CR-LSP phai di qua Niit triru tugng cd the la mpt niit hoac mpt nhdm niit N I U ER chi quy dinh mpt nhdm trong sd cic mit ma CR-LSP di qua thi nd dugc gpi la tuyen tudng minh tha long (loose ER) Ngugc lai, nlu ER quy dinh toan bp cac mit tren CR-LSP thi

9

7.2.3 Dieu khi^n luu lirong dua tren MPLS

MPLS-TE dk cap din kha nang dilu khien cua nhiing luong luu lupng trong ma

vdi muc dich giam thieu tic nghen va tao ra miic su dung hieu qua nhat cbo cac phuang t sin cd Luu lupng IP truyin thdng dinh tuyen theo "Hop by Hop" co ban va theo IGP k sii dung ky thuat dudng dan ngan nhat de truyen luu lupng Luu lugng dudng dan IP coi khong dat tdi uu vi nd phu thupc vao thdng tin Link Metric tinb khdng ciing vdi bat ky n hieu biet nao ciia tai nguyen mang sin cd hoac cac yeu cau cua luu lugng can thiet de ma tren dudng dan dd Su dung ky thuat dudng dan ngin nhat cd the gay ra cac van de sau :

^ Dudng dan ngan nhat tii cac tai nguyen khac nhau chong lan len mpt so link, g

ra tie nghen tren cac link dd

^ Luu lupng tu mpt nguon di tdi mpt dich cd the vugt qua dung lugng ciia ky thi

dudng dan ngin nhat, trong khi mot dudng dan dai hon giua hai Router dd dupc dugc; dung khong diing miic

Ky thuat luu lupng trong pham vi MPLS phat sinh tu nhu cau khai thac mang de cur cap mpt CO sd ha tang mang dang tin cay va dua ra su thyc hien nhat quan cho mang F thuat luu lugng cho phep ngudi khai thac mang kha nang dinh tuyen lai luong luu lugng dudng dan cost thap nhat "least cost" dugc tinh toan boi cac giao thiic djnh tuyIn va nhui dudng dan vat ly it bi tac nghen trong mang do Va ket qua la eo sy gia tang rit manh n trong nhu cau ve tai nguyen mang va su canh tranh giiia cac nha cung cip Ky thuat li lugng da tro thanh ling dung hang dau eho MPLS Muc dich eua ky thuat luu lupng laph

su dung hieu qua \ ao tai nguy en mang gidi ban

Trong hinh 7.3 ed hai dudng dan tir Router C tdi Router E dugc bieu thj boi cac duor dan 1 \a 2 neu mpt Router chpn mpt trong cac dudng din theo ky thuat dudng dan ngi nhat tir C tdi E ( C-D-E) thi sau do no se mang tit ca luu lugng cua dich eho E thong qi dudng din Dung lupng luu lupng eu6i eung tren duang din dd co the gay ra tic nghe trong khi mpt dudng din khac (C-F-G-H-E) khong duge su dung De toin'the mang^ho

dpng hieu qua nhdt no cd the thilt kl nham tha> doi mpt xai phan s6 (fraction) eua luu \m

tir link nay toi link khae Trong khi ta co eost duong din C-D-L ngang bang vdi cost duc^

din C-F-(;-H-E nhu la N iee tiln lai gdn hon va\ su cdn hang tai se gay can tro nlu khonel

Trong hinh 7.3, cd hai dudng dan tir Router C tdi Router E dugc bieu thi bdi cac dudng dan 1 va 2, neu mpt Router chpn mpt trong cac dudng dan theo ky thuat dudng dan ngan nhat tir C tdi E ( C-D-E), thi sau dd nd se mang tat ca luu lugng cua dich cho E thong qua dudng dan Dung lugng luu lugng cudi ciing tren dudng dan dd cd the gay ra tac nghen, trong khi mot dudng dan khac (C-F-G-H-E) khdng dugc sir dung, De toan the mang boat dpng hieu qua nhat nd cd the thiet ke nham thay ddi mpt vai phan sd (fraction) cua luu lugng tir link nay tdi link khic Trong khi ta cd cost dudng dan C-D-E ngang bang vdi cost dudng dan C-F-G-H-E nhu la viec tien lai gan hon vdi sy can bang tai se gay can trd, neu khdng the cd dugc mpt Topo mang chat che Cac dudng dan ciia dinh tuyen tudng minh, dugc thyc hien sir dung MPLS, cd the dugc sir dung de hieu ban va mem deo han ciia viec dinh dia chi van de nay

De giai quyet van de dieu khien luu lugng dua vao mpt thyc te la cac nhan

va cac dudng dan Label-switched cd the dugc thiet lap mpt each da dang ciia each kieu dieu khien khic nhau Vi du, kieu dieu khien luu lugng cd the thiet lapmpt dudng dan Label-switched tir B tdi C tdi F tdi G tdi H tdi E (dudng dan 1) va mpt dudng dan khac tir A tdi C tdi D tdi E (dudng dan 2) nhu dugc chi ra d hinh 7.4

Router D Router A

link-state IGP Theo yeu cau de dilu khien dudng dan LSP dat hieu qua moi LSP co dugc gan mpt hoac nhieu hon cic thupc tinh Nhiing thupc tinh nay se xem xet trong du dan may tinh de cho LSP Cic thupc tinh nay va y nghia ciia chiing dugc long ket nhu sau

^ Bandwidth: Dp rpng bang thdng du trir tdi thieu cua dudng dan cho LSP d thiet lap dpc theo dudng dan dd

^ Path Attribute: Mpt thupc tinh dupc quyet dinh la dudng dan ciia LSP co tb

Manually specified hoac Dynamically hay khdng thi dupc tinh bdi Constraint-Based roulii

^ Setup Priority: Thupc tinh nay se quyet dinh la LSP nao se tao ra tai ngu]

khi nhieu LSP hoan thanh cho nd

^ Holding Priority: Thupc tinh nay se quyet dinh la mpt tai nguyen dugc giir

mpt thiet lap LSP thi se dupc uu tien trudc bdi mpt LSP mdi hay khong

^ Affinity (Color): Viec quan ly die trung die tinh ciia mdt LSP

^ Adaptability: Cd hay khong viec chuyen mach LSP tdi mpt dudng dan toi hon khi no tro nen cd san

^ Resilience: Thupc tinh se dupc quyet dinh hay khong de djnh tuyen lai LSPl dirdng dan cd anh hudng do loi

Kha nang cua MPLS la cung cap viec dinh tuyen ro rang, boat dpng qua bat ky ir phuong tien nao va cd the tap hgp so lieu thong ke nhirng LSP dl dl nghi nd la thich h cho cung edp kha nang ky thudt luu lugng

IETF dua ra gia thiet ve 2 giao thu'c khac nhau cho vice danh rieng tai nguyen tro pham vi cu the la MPLS, dinh tuyIn dua tren sy rang budc Constraint-Based Routing, da

su dung giao thirc phdn phoi nhan LDP (CR-LDP) vd giao thiic danh rieng tdi nguyen RS^

de cung cdp cho ky thudt luu lugng trong pham vi miln MPLS

7.2.4 Phan tich thuat toan

• Mieu td md hinh

Trong cdc mang MPLS, khi ed mpt lien kit hay mpt tram bj ldi thi ede ludng luu lug qua tuyen chira lien kit bi 16i thi cae cupc gpi hoac la bi ngin quang (dropped) hoac lapl djnh tuyen lai nlu eon eo tuyIn du phong Khi tuy In bj ldi duge nhd lai ngirdi ta cd thexc xet hoac la tra lai tuy In dd luu lugng nguyen thuy ban ddu Mot tiln tiinh Markov qu) djnh (A Markox Decision Process - MDP) dupc lua chpn de xem xet mot cdch tdi uu M lieu tra lai luu lugng cuoc gpi tir tuyIn du phong tro lai tuyIn ban ddu la nhu thi nao (b

nhieu ??) P Aukia \1\ da dua ra dl xudt nhu sau

Kha nang ciia MPLS la cung cap viec dinh tuyen rd rang, hoat dpng qua bat

ky mpt phuang tien nao va cd the tap hgp sd lieu thong ke nhimg LSP, de de nghi nd la thich hgp cho cung cap kha nang ky thuat luu lugng

IETF dua ra gia thiet ve 2 giao thiic khac nhau cho viec danh rieng tai nguyen trong pham vi cu the la MPLS, dinh tuyen dya tren sy rang budc Constraint-Based Routing, dang sir dung giao thiic phan phdi nhan LDP (CR-LDP), va giao thiic danh rieng tai nguyen RSVP de cung cap cho ky thuat luu lugng trong pham vi mien MPLS

7.2.4 Phan tich thuat toan

• Mieu td mo hinh

Trong cac mang MPLS, khi cd mpt lien ket hay mpt tram bi ldi thi cic ludng luu lugng qua tuyen chira lien ket bi loi thi cic cupc gpi hoac la bi ngan quang (dropped) hoac la phai dinh tuyen lai neu cdn cd tuyen dy phdng Khi tuyen bi loi dugc nhd lai, ngudi ta cd the xem xet hoac la tra Iai tuyen dd luu lupng nguyen thuy ban dau Mpt tien trinh Markov quyet djnh (A Markov Decision Process -MDP) dugc lya chgn de xem xet mpt each tdi uu viec lieu tra lai luu lugng cupc gpi tu tuyen dy phdng trd lai tuyen ban dau la nhu the nao (bao nhieu ??) P Aukia [7] da dua ra de xuat nhu sau

• Md hinh tuyen A'2

Tir [1, 3, 4, 5], ngudi ta da cau hinh trudc tao ra tuyen dy phdng trong mang

de khoi phuc tuyen mpt each nhanh nhat, Vi the mpt md hinh 2 tuyen (ma chimg dugc coi nbu 2 tuyen song song vdi nhau) ndi giira tram nguon S vdi tram dich D Tuyen nguyen thuy (tuyen so cap) dugc gpi la P va tuyen thii cap (tuyIn dy phdng) dupc gpi la B Mdi cupc gpi dugc gii thiet la chiing cd ciing mpt dan vi bang thong (trudng hgp tong quit thi moi cupc gpi se cd bang thdng khong nhu nhau, nhung se dugc de cap sau nay) Tuyen so cap P cd the bi Ioi hay bi gian doan do mpt tram hay mpt lien ket bi diit Sau khi Idi xay ra, tat ca cac cupc gpi qua tuyen dd se dugc di chuyen tir tuyen so cap P tdi tuyen dy phdng B TuyIn

so cap dugc nhd lai sau khi toan bp hay mpt phan luu lupng cac cupc gpi qua dudng dy phdng B se dugc di chuyen trd Iai dudng so cap P (xem hinh 7.5, trong dd - LHS: trudc khi hdng ; MID: sau khi hdng ; RHS:sau khi nhd Iai)

n

dugc chuyen lai ve tuyen so cap P vdi mpt chi phi nhat dinh (mui ten xanh luc o hinh 7 luu lugng dugc chuyen la cd ban, thudng bj gidi ban bdi cdng suit cua tuyen so cap P hi

cua tuyen thir cap B neu luu lugng d tuyen P ldn hon d tuyen B, mot sd nhirng cupc gpi

bi loai bd trong luc ddi hudng ldi nhu vdy luu lupng cdn lai sau khi tuyen so cap hoi pl

se van la hiiu han va nhu the, chiing ta se chi xem xet trudng hpp gidi ban tren la cong s; ciia tuyen so cap bdi trudng hpp gidi ban tren la cong suat tuyen thir cap cung tuong tu

• Cdc dgi lugng vd cdc luu y

• M: Dung lupng ciia tuyen nguyen thiiy (so cap) xac djnh so cupc gpi toi da cot

chiem giir

• / / : Toe dp loi eua tuyen so cap

• /// -• Toe dp nhd lai tuyen so cdp Thdi gian nhd lai trung binh la (p-1),

• / ; Toe dp cupc gpi den

• jU- T Thdi gian phuc vu cupc gpi trung binh cua cac cupc gpi

.A.-I

,^'X^ " " ^ - - ^ 7 ^ ,

ITinh ~ 6 • Mo hinh loan hoc cua mang 2 iiivSn

• Cl.- Giu trpng so toe dp cupc gpi qua tuyIn so cap P

• Cy- Giu trpng so toe dp cupc gpi qua tuyIn du phong B

• C/A-/+ C2X:: Giir trpng so cdc cupc gpi tir S tdi D Trpng s6 dupe gia djnh la mot ha

tuyen tinh cua cdc cupc gpi hien hdnh dang chiim giCr

• em: Di chu>en trpng s6 tie dp cupc gpi Di chuyen trpng sd dupe gia djnh la mgl h^

tu>en tinh eua tong s6 cac cupc gpi dang dupc di chuyen cm

• (A-/, A-:, p,): Trang thai hien hdnh trong do Xj xj Id cdc cupc gpi chiim giir tren tuyeni

edp P N a tuyen du phong B va p, la trang thai hien hanh cua^uyen so cdp Khi p, =' luyen so cap lam Nice vd khi p^ - 1 thi tuyIn so edp bj 16i (dirt)

Co hai mat phang trong hinh 7.7 Mat phang thir nhdt khi p, = 0 dilu nav cd nghia tu>en so cdp lam Mee u3t Lue ddu tien ngudi ta gia djnh eo v cuoc goi qua tuyIn so cap

Xf: Tdc dp ldi cua tuyen so cap

Pf: Tdc dp nhd lai tuyen so cap Thdi gian nhd lai trung binh la (p-l)/

X : Toe dp cupc gpi den

p-l: Thdi gian phuc vu cupc gpi trung binh cua cac cupc gpi

« j p = @ ZD o /;

j ' - , n ' l

^ X = n + -(-.: V ;

D Hinh 7.6 : Mo hinh todn hoc ciia mang 2 tuyen

• c/.- Giir trpng sd tdc dp cupc gpi qua tuyen so cap P

• C2: Giir trpng sd toe dp cupc gpi qua tuyen dy phong B

• C/Xy+ C2X2: Giu trpng so cac cupc gpi tir S tdi D Trpng sd dugc gia dinh la

mpt ham tuyen tinh cua cac cupc gpi hien hanh dang chiem giir

• cm: Di chuyen trpng so toe dp cupc gpi Di chuyen trpng sd dupc gia dinh

la mpt ham tuyen tinh cua tdng so cac cupc gpi dang dupc di chuyen zm

• (xi, X2, Pf): Trang thai hien hanh, trong dd x/, X2 la cac cupc gpi chiem giir

tren tuyen so cap P va tuyen du phdng B, va pf la trang thai hien hanh ciia

tuyen so cap Khi pf = 0, tuyen so cap Iam viec va khi pf = I thi tuyen so cap

bi loi (diit)

Cd hai mat phang trong hinh 7.7 Mat phang thii nhat khi pf ^ 0, dieu nay

cd nghia la tuyen so cap lam viec tot, Luc dau tien , ngudi ta gia dinh cd y cupc

gpi qua tuyen so cap B va khong cd cupc gpi nao qua tuyen dy phdng B Khi P bj Ioi (bi diit), cac ludng dupc di chuyen tir P tdi B Vi the trang thai cua he thong

thay ddi tir (y, 0, 0) thanh (0, y, 1) vdi tdc dp dich chuyen la X/ Khi P dupc nhd lai vdi tdc dp pf, ngudi ta phai ra quyet dinh xem cd bao nhieu cupc gpi se dugc

di chuyen trd lai P Trang thai cua he thdng Iai thay doi tir (xi, X2, 0) trong dd Xi + X2 < y (tiiy thupc vao cd dich vu nao da dupc hoan thien tren B trong khi nhd lai cac tien trinh ciia P) Khi tuyen so cap lam viec tot trd Iai, ngudi ta cd thi gia dinh lai cd them mpt sd cupc gpi mdi den hoac di tren ca P Ian B

15

Do dd p.d.f f^iT) = re-''.T>0 vdi tat ca gia tri cua x z Ky v(

El T] = r rre-'dr = - Trang thai va dilu khien tai thdi diem t bdt ky dupc dinh ng

S) y

bdi x(i) va r(/) tuong irng va khong doi giiia cac chuyen giao

Chung ta su dung cac dinh nghia sau:

- t/, la thdi gian chiem ciia chuyen giao thir k (t,, = 0)

r^ I t^ -r^._,: khoang thdi gian chuyen giao thir k

x^ ~ x(/r): chimg ta cd x{(} = \^ vdi /^ <t<t^^^

- Zk Z z(k): chiing t a c d r(/) = ^ vdi t^ <t <t^^^ r - (a, J.r, /;,} e {O.ll'

Chiing ta xem xet mpt ham chi phi cd dang:

Y\m^{[ cCx{t).'z{t))dt\

Trong do c la mpt ham cho trudc (ham djch chuyen va/hoac ham giir) dupc mo trong phdn trudc Tuong ty vdi bai loan thdi gian rdi rac mpt chinh sat

Z = |z„,Z| | trong dd Zk la mpt trang thai anh xa ham den cdc dieu khien v

Zk(x)GZ{x) vdi tat ca gia tri x Vdi z dieu khien dupc dp dung trong khoar

Chiing ta sir dung cac dinh nghia sau:

- tk la thdi gian chiem cua chuyen giao thii k {to = 0)

- '^k=t,,- ^i_,: khoang thdi gian chuyen giao thir k

Xk = x(k): chiing ta cd x(/) = x^ vdi /^ < / < /^^i

chinh sach Z = |zo,Zi, } trong dd zk la mpt trang thii anh xa ham den cic

dieu khien vdi zk(x) e Z(x) vdi tat ca gia tri x Vdi z , dieu khien dupc ip dung trong khoang [^^,^^^+1) la Zk(xk)

Do trang thai khdng doi giira cac chuyen giao (nghia la trong thdi gian / " ' ) , ham chi phi dugc cho bdi:

Trong dd, mot tien trinh Markov thdi gian lien tuc vdi chi phi

\™^^^E\r c{x(t\z{t))dt\vk toe dp chuyen giao y se tuong duong vdi

mpt tien trinh Markov thdi gian rdi rac vdi chi phi long-run tren mpt giai

Trong hinh 7.9 , tir trang thai hien thdi (0 X2 0), cac su kien co the den ducn^ dan so cdp P la sy kien den ciia 1 luong mpt that bai va sy kien di tir duong dy phorij

Nhu thdy trong hinh 7.10 khi xj - M tdt ea eae su kien den cua luong deu bj kh(

d dd\ chiing ta khong xet den trudng hgp khi ma cac luong bi nghen ludng dugc dii tuyen den dudng du phdng Chi eo the xay ra cac su kien di \ a that bai Cl

Nhu thay trong hinh 7.10, khi X2 = M, tat ca cac sy kien den ciia luong

deu bi khoi d day, chiing ta khdng xet den trudng hgp khi ma cac luong

bi nghen ludng dugc dinh tuyen den dudng dy phdng Chi cd the xay ra

cac sy kien di va that bai Cbo YQM o- ^r "•"^/^' chiing ta cd:

Hinh 7.10 : Trang thdi dich chuyen Markov (OM, 0)

iv) 0 < Xl < A/, A:^ = 0, pf= 0

Hinh 7.11 cho thay khdng cd Iuong nao tren dudng dy phdng B va dudng so cap P khdng bi lap day bdi cic ludng, cd cac sy kien thit bai, sy

kien den va di Vdi tdc dp dau ra long la Y.^^.o^ - ^ + ^f+x^jj, ^ chimg ta

CO

19

luu tru hoac that bai Khong co su can bang luu lugng a day Cho

Hinh "" 13 : Markov Iransitions of the slale (xl x2, 0) khi xl + x2 < M

• Ap dung giai thudt dieu khien lint lugng trong mgng MPLS

Tir eae mo hinh todn hpc tren trong cac giai thudt thyc te cdn dam bao rang tdt ea cac Im lugng mang phai dugc djnh tuyen mpt each hieu qua ddng tin cdy vd cd chat lugng djch vi (QoS) cao Hon niia luu lugng eua mang dupe phdn phoi mpt cdch hieu qua trong cac la nguyen mang Trong mang MPLS, ky thudt luu lupng mang su dung ky thuat tim duani cudng birc ngan nhdt (CSPF) thay vi OSPF trong cac mang IP trudc dd de thuc hien diei khien luu lupng CSPF tim dudng di cho dir lieu can cir \'ao ede dieu kien dinh tuyen duara Tu\en nay c6 the khong phai la tuyen ngan nhdt nhung it nghen hon tuyen ngan nhat Djn, luyen tudng minh la mpt tap hpp con eua eae tuy en cudng birc thdng thudng dudi dieu kie cudng birc nhu la mpt tuyen tirdng minh Mot tuyen tirdng minh la mpt LSP ma nd gui d lieu tren mpt tuyen nhdt djnh thong qua mien MPLS

Trong mang MPLS, dang thong tin trao doi giua cac tuyen phu thupe vao giao thuc ba hieu se duge su dung Cd bon phuong thirc duge xae djnh nhu sau 1111: Giao thirc phdn phi

///rt/i 7 / J • Trgng thdi dich chuyen Markov (xl, x2, 0), khi xl + x2 < M

• Ap dung gidi thuat dieu khien luu lugng trong mgng MPLS

Tir cac md hinh toan hpc tren, trong cic giai thuat thyc te can dam bao rang tat ca cic luu lugng mang phai dugc dinh tuyen mpt each hieu qui, ding tin cay

va cd chat lugng dich vu (QoS) cao Han nira, luu lugng cua mang dugc phan phdi mpt cich hieu qua trong cac tai nguyen mang Trong mang MPLS, ky thuat luu lugng mang sir dung ky thuat tim dudng cudng biic ngan nhat (CSPF) thay vi OSPF trong cac mang IP trudc dd de thuc hien dieu khien luu lugng CSPF tim dudng di cho du lieu can cii vao cac dieu kien dinh tuyen dua ra Tuyen nay cd the khdng phai la tuyen ngan nhat nhung It nghen ban tuyen ngan nhat Dinh tuyIn tudng minh la mpt tap hgp con ciia cac tuyen cudng biic thong thudng dudi dilu kien cudng birc nhu la mpt tuyen tudng minh Mpt tuyen tudng minh

la mpt LSP ma nd giri du* lieu tren mpt tuyen nhat dinh thong qua mien MPLS

Trong mang MPLS, dang thdng tin trao ddi giu:a cac tuyIn phu thupc vao giao thirc bao hieu se dugc sii dyng Cd bon pbuang thirc dugc xac dinh nhu sau [11]: Giao thirc phan phoi nhan (LDP), giao thirc dinh tuyIn cudng birc vdi LDP

21

Thdi gian gian doan djch vu = Thdi gian do loi + thdi gian thong bao den toan

mang + Thdi gian tinh toan dU phdng + Thdi gian chuyen tiep ludng lUu lu'dng

• Cdc ca che khdi phuc tuyen trong mgng MPLS

Khoi phuc tuyen trong MPLS la co che trong dd luu lugng dang dugc truyen tai dugi

chuyen tiep cho mpt tuyen mdi dupc gpi Id tuyen dy phdng khi ma tuyen hien tai xay ra loi

Qua trinh ndy nham ddm bao thong tin truyen dan khong bj mdt Tuyen dy phdng dugc tinl

loan vd thiet lap dua vdo co che khoi phuc 1 rong RSVP-'FE loi cd the dugc phat hien hdi

cdc ban tin Hello hoac trang thai mem RSVP-TL Mot khi ldi dugc phat hien vd thdng bac

den node loi vdo nd sc co gang de thiet lap lai mpt LSP tuong ty Neu LSP nay dugc dinli

tuyen mpt each long leo thi LSR loi vao cd the thu tim mpt tuyen va node ma khae tuyen vdi

node dau vdo va co gang thiet lap mpt LSP tren tuyen mdi de thay the Hay ndi mot each

khac no se co gang thiet lap mpt LSP va de node bien bj loi tinh todn mpl tuyIn mdi tu

node/link den LSR bien Sau khi tuyen mdi dupe thiet lap tdt ca cac luu lugng dugc chuyen

tiep \ao tuyen nay

Co hai loai co che sua tuyen ehiing dupe gpi la eo che sua tuyen loan cue va sua tuy^J

cue bp I

• Sua chua toan cue dupe khoi tao giua ede nodes dau eudi I uyin dupc lya chon la

tuyen dupc tinh loan trudc dd hoac la tuy en dupc tinh todn mot cdch nang dpng lu cac

node bien (bao gom node dau vao vd node dau ra) TuyIn dupe lya chpn Id tuyIn bao

ve cua tuy en dang cd du lieu truyen qua

• Sua chira cue bp dupc su dung de sua ldi tai cac dilm xay ra ldi hoac gan diem xay ra

loi Do \ ay nd giam thieu so lugng mat goi dir lieu Flon thi nira qud trinh sua loi

dugc thuc hien mot cdch cue bp din node or link xay ra ldi do vdy qua trinh khoi phuc

se dien ra nhanh hon

• Mot so md hinh khdi phuc tiivin

Cd rat nhieu mo hinh khoi phuc LSP trong mang MPLS, nhung mo hinh Makam va Haskiij

dupe coi Id mo hinh phii hgp nhdt Mo hinh cua Makam va Haskin dai dien eho hai phuanij

thue khdi phuc tuyen: todn cue xh cue bp Han nira hai mo hinh ndy t6t hem cae md hinli

khoi phuc khde tren phirong dien s6 lupng gdi bj mdt s6 lugng mdt trat ty ^(^^ tin '

i

Khi mpt link hoac mdt node tren tuyen giiia node truyen va node nhan bi ldi, dich vu se bj ngat cho den khi bon budc tren dugc hoan thanh Thdi gian giin doan dich vu la khoang thdi gian giiia bit truyen di cuoi cimg trudc khi ldi xay ra dugc nhan va thdi diem bit dau tien cua dii lieu ma sir dung tuyen dy phdng den dugc bp nhan Tdng thdi gian gian doan dugc tinh toan theo cdng thiic sau:

Thdi gian gian doan djch vu = Thdi gian do loi + thdi gian thong bao den toan mang + Thdi gian tinh toan du* phong + Thdi gian chuyen tiep luong lUu (Udng

• Cdc ca che khoi phuc tuyen trong mgng MPLS

Khdi phuc tuyen trong MPLS la ca che trong do luu lugng dang dugc truyen tai dugc chuyen tiep cho mpt tuyen mdi dugc gpi la tuyen dy phdng khi ma tuyen hien tai xay ra ldi Qua trinh nay nham dam bao thdng tin truyen dan khdng bi mat Tuyen dy phdng dupc tinh toin va thiet lap dya vao co che khdi phuc Trong RSVP-TE, ldi cd the dugc phat hien bdi cic ban tin Hello hoac trang thii mim RSVP-TE Mpt khi ldi dupc phit hien va thong bao den node loi vao,

nd se cd ging de thiet lap lai mpt LSP tuong ty Neu LSP nay dugc dinh tuyen mpt each ldng leo thi LSR loi vio cd the thir tim mpt tuyen va node ma khac tuyIn vdi node dau vao va co gang thiet lap mpt LSP tren tuyen mdi de thay the Hay ndi mpt each khac, nd se co gang thiet lap mpt LSP va de node bien bi ldi tinh toan mpt tuyen mdi tir node/link den LSR bien Sau khi tuyen mdi dupc thiet lap, tit ca cac luu lugng dugc chuyen tiep vao tuyen nay

Cd hai loai co che sira tuyen, chimg dugc gpi la ca che sira tuyen toan cue va sira tuyen cue bp

• Sira chiia toan cue dugc khdi tao giira cac nodes dau cudi Tuyen dugc lya chpn la tuyIn dugc tinh loan trudc dd hoac la tuyen dugc tinh toan mpt cich nang dpng tir cac node bien (bao gom node dau vao va node dau ra) TuyIn dugc lya chpn la tuyen bio ve ciia tuyen dang cd dir lieu truyin qua

• Sira chira cue bp dugc sir dung de sira ldi tai cac diem xay ra 16i hoac gdn dilm xay ra Ioi Do vay, nd giim thieu so lugng mat gdi dir lieu Hon thi nira, qua trinh sira Idi dugc thyc hien mdt each cue bd din node or link xay ra ldi do vay qua trinh khoi phuc se dien ra nhanh hon

23

Mpt khi node S do thay ldi tren tuyen dang van hanh tdt ca luu lugng se dugi

chuyen tilp tryc tilp tren tuyIn dy phdng thay vi tuyen so cdp Mpt dieu dang luu)

niia la khi node S nhdn dugc gdi tin ddu tien tir tuyen ngupc cac gdi tin tiep tuc duo(

giri thong qua tuyIn so cap bi loi Nhirng gdi tin nay se bj tre tren 2 tuyen trong kh:

truyin tren dudng vdng ngugc tir node ddu vdo den LSR cudi cimg tai diem xay ra loi,

Mpt dilm bdt lgi nira la cic gdi tin den tir hudng ngugc se bi trpn vdi cac gdi tin dang

dupc truyin din Do dd cac gdi tin se bj mat trat ty khi qua tuyen dy phdng trong qua

trinh khoi phuc tuyln Diem bdt Ipi cuoi ciing la tai thdi diem xay ra loi cac goi tin

quay vong tren cdc link loi cd the bj mat

ii) Md hinh cita Makam

Trong mo hinh nay [3, 4] tie gid Makam da de xudt mpt phuong phap su dung

cac dudng dy phdng dugc thiet lap tir trudc

Budc ddu tien nha quan trj mang se tinh loan tuyen tdi uu va thiet lap no la

tuyen so cap va chpn tuyen toi uu thir hai ldm tuyen du phdng Sau dd, thong tin se

dugc truyen tren tuyen so cdp

LSR 3 Pre-established

alternaln/e pat

LSR 2

Hinh ~.I6: Thiei lap luven du phong

Khi CO loi xdy ra tren bdt cir lien ket nao tren tuyln so cdp node LSR se gui'

ban tin FIS de danh dau cd loi va chuyen ban tin nay ngugc lai node ddu vao Mpt khi

node ddu vao nhdn dugc ban tin FIS no se chuyen ngugc todn bp luu lupng ddu vao

den tuyen dy phdng Va ciing tai thdi diem dd lien kit ldi tren tuyln so cap se dugc

sua ehira (Hinh ve) ,

Hinh " / ~ Dinh tuven Igi

Phuong phap nay cung cdp hieu qua su dung tai nguyen tot hon la phuong phap Haskin bdi vi dp dai cua tuyen bdo ve dugc sir dung trong qua trinh khoi phuc tuyen nhd ban so vdi md hinh Haskin Tuy nhien nhugc diem ciia mo hinh Makam la luu lugng ma chuyen tiep trong mot khoang thdi gian giira thdi diem do thdy loi va thdi diem ban tin FIS den dupc LSR dau vdo cd the bj mat Hon nu"a nhung gdi tin quay vdng tren tuyen Ioi khi xay ra Ioi eung cd the bj mdt

Link break

7.3 Muc tieu va Npi d u n g Nghien CLFU cua 0 § tai

7.3.1 Muc tieu ciia de tai

• Nghien eiru van de dieu khien luu lugng \ a khoi phuc dudng truyen mang MPLS ba gom ea ly thuyet chung ldn kT thudt dieu khien

• Mo phong \a khao sdt phuong thirc dieu khien luu lugng vd khdi phuc dudng truye

su dung NS-2 Dya tren NS-2 su dung eae chuong trinh tinh todn de khao sat mpis thong so nhu dp mdt mat gdi tin dp mdt trat tu eua gdi tin cua cae phuong thirc khi phuc tuyen Makam va Haskin

• Thiet ke mo hinh mang MPLS ao tai phdng thi nghiem He thdng Vien thong lhu nh

su dung cong nghe MPLS de phuc \u cho ddo tao cho sinh vien ede kiln thirc thircti

7.3.2 Tom tat noi dung nghien cuu cua dc tai

Nghien eiiu ede giai thudt dieu khiC'n luu luone hien ed

+ Tinb toin, md phdng va thir nghiem giai thuat dieu khien luu lupng cho MPLS + De xuat y tudng xay dyng mang MPLS do tai Phong thi nghiem bp mon

7.3.3 Tinh da nghanh va lien nghanh cua de tai:

De tai thyc hien nghien ciru ldp lien ket dir lieu va ldp mang IP trong mo hinh OSI Id chu yeu Giai thuat dieu khien luu lupng lien quan den cac ldp cao hon (cd ldp truyen tin) vd cac ldp dudi hinh thanh nen giao thirc da ldp, cdc tien hanh danh gia thong qua mo phdng dya tren cac ngdn ngii lap trinh bac cao doi hdi sy tham gia ciia nghanh cong nghe thdng tin

7.4.1 Phuang phap luan va phu-ang phap khoa hoc su- dung trong dc tai:

+ Nghien ciiu phdn mem mo phong NS2:

+ Nghien ciru iing dung xu ly thong dn trong truyen thdng,

+ Nghien cuu cac thudt loan , gidi thuat mo phong

7.4.2 Kha nang sii- dung co* sa vat chat, trang thiet bj:

D I tai dy kiln sir dung mpt so trang thiet bj sau cua phdng thi nghiem (PTN) eua bp mon thdng tin vo tuyln, PTN ciia bp mon he thdng Vien thdng va PTN cdc he thong tich hpp thong minh

• Mdy tinh cd nhdn chay tren he dieu hanh Window

• May tinh ehii Unix (Linux) de thuc hien mo phong tren NS2

• Mang Internet va he thong mang ciia VNU

• Cac thilt bi do dac khac nhu Dao dpng ki Volt ke so phan tich pho phdn tich mang

7.4.3 Cac boat dong nghien ciiu cua de tai tai VNU:

• Nghien ciru li thuyet 0

• Dieu tra khao sat 0

• Bien soan tai lieu 0

• Vilt bdo cao khoa hpe 0

• Hoat dpng khac 0

27

(Thilt kl va kiem chirng qua md phdng)

• Chay thu kiem nghiem 0

(Chay thir cac giai thuat tren kit FPGA neu cd)

• Hpi thao (Seminar) 0

7.5 Kit qua nghien CLFU :

7.5 L- Ket qud nghien cmi :

- Da cong bd 02 bdo cao khoa hpc tai hpi nghi Quoc te trong nudc REV*06 va HUT'08

• P.T Hong' Phi-Hung Pham^ Xuan-Tu Tran" and Chui woo Kim' "Analysis am

Evaluation of Traffic-Performance in Backtracked Routing Network-on-Chip HUT-2008 Abstract: VLSI designers recently have adopted micro network-on-chi

(or NoC) as an emerged solution to design complex SoC system under stringer constraints pertaining cost size, power consumption, and short time-to-marke Characterization of on-chip traffics and traffic-performance evaluation are necessar steps bringing comprehensive and effecti\e NoC design This paper presents a analysis and performance evaluation framework of backtracked routing Network-or Chip that provides guaranteed and energy-efficient data transfer Experimental result: under common and application-oriented synthetic traffics, figure out the performanc

in terms of latency and throughput and suggest a tradeoff to developers to ma

applications into a proposed NoC platform Acknowledgment: ** This work was co

supported by the Korea Research Foundation (KRF) and by Vietnam Natiow University Hanoi through research project No QC 07.18"

- Pham T.Hong Nguyen Quoc Tuan Bui Trung Ninh Nguyen Kim Giat

"Perfomance evaluation of some recovery models MPLS " Abstract: The MPL!

technology is a combination of flexible routing in IP and the bight-speed switch i ATM One of the key reasons to employ MPLS in traffic at a failed or congested! rerouted This paper presents and evaluates to\s recovery models: rese\erse baekupt Haskin's model and route guarding or Makam's model by comparing the performanc metrics of these models such as: packets loss ser\iee disruption time, resourc uiili/alion using NS-2 software and specific alaly sis tools

7.5.2 Ket qud ddo tgo cua De tdi:

02 khoa luan sinh vien bac dai hpc tham gia

• Nguyen Kim Ngoan, 'Tath Protect Mechanism in MPLS Netwwork

3 QoS MPLS Network Recovery

QoS MPLS Recovery Mechanisms

Recovery Path Placements

2 MPLS overview

2.1 Architecture MPLS Networks 2.1.1 Physic Layer

2.1.2 Data Link Layer 2.1.3 Network Functions 2.2 MPLS Protocols

2.3 MPLS Operation

29

3 FAILURE DETECTION / NOTIFICATION IN MPLS

3.1 Failure Detection 3.1.1 RSVP-TEHello 3.1.2 RSVP-TE Softie 3.1.3 Haskin model 3.2 Simulation and Analysis 3.2.1 MPLS protocol in the network simulator NS 3.2.2 Results

4 Conclude

7.6 Thao luan

Kit qua thu dupc trong khi thyc hien de tdi da hodn thanh dupc cac npi dung co ba

da dat ra khi dang ki de tai Tuy nhien do pham vi gidi ban ve mat thdi gian nghien ciru( nam) va kinh phi nghien ciru do do de tai chua tim ra hudng di mdi trong ITnh vuc na) Nhung ciing da dua ra mpt mpt so ket qua trong viec danh gia va so sanh kT thudt dieu khie luu lugng trong mang MPLS, cdc ket qua nay da trinh biy trong 2 bao cao khoa hpc tai ca hpi nghj quoc tc hang ddu ve ITnh vyc mang \a Iruyen thong trong khu vue Asia (Re\ \ HUT)

7.7 K i t luan va k i l n nghi

Cae mang khong ddy 3G/4G dang hira hen vice trien khai rpng rai tai Viet nam va trei todn the gidi Khi ra ddi (c6 tinh thuong mai) nhieu van de con phai giai quylt trong d mang loi cua khong ddy 3G/4G dua tren nen tang MPLS do vdy viec tilp tue tim kilm ca giai phap cong nghe irng dung xir li thong tin xu li so tin hieu de tim kilm eae giao thirc mo

la can thiet Day la cong viec vira c6 tinh khoa hpc vira co tinh ddo lao tai trudng Dai ho Cong nghe

7.8 Tai lieu tham khao

[1] D Awduehe et ak .Extensions to RSVP for LSP Tunnels., work in progress, draft-iell mplsrsvp-lsp-tunnel-08 Feb 2001

[21 I Andrikopoulos et al Supporting Differentiated Services in MPLS Networks lEEi Ineternational Workshop on Quality of Service, pp 207 215 1999