hanh. cung nhu tndn khai dc mang da dich vu cd the ho tro ddng thdi TDM. Ethemet.
IP... vdi bing thdng Idn hon da khidn van de tich hop da ldp trd thanh mdi quan tim hidn nay trong linh vuc mdn thdng Cic mang tich hap da Idp cd nhieu uu thd vuat trdi trong vide dap ung nhu du ngiy cang cao vd bang thdng trong tat ca cac mang truyen thdng, chii ydu li nhu du sir dung cic dich vu da phuong tidn trong nhieu Unh vuc vi tren nhieu loal thiet hi khie nhau, bao gdm cdng nghd di ddng 4G. Bai vidt 0di thidu dc kidn tnic trien khai mang tich hop da ldp IP/MPLS tren OTN/WDM.
T O N G Q U A N MANG T I C H HOP DA LOP
Trude khi tta bidu cdc tfty chpn Wdn tnic tridn khai mang tieh hpp da ldp, ta eta ndm rO co sd vd ly do eta bdi tu (tich hpp) cdc Idp mang ndy. 6 ddy chtog ta sd tta hidu vd ldp IP vd ldp WDM (Wavelengtii- division multiplexing) ttong ehdng ngto xdp 0ao thue mdng lOi eiia tod khai thdc.
Ldp IP thftc hidn hai chftc ntog: Djto tiiydn bidn tod eung edp (PE- Provider Edge) vd djto tiiydn tod cung edp (P Provider). Cdc bd djto tiiydn PE hd bp mdt loat cdc 0ao thfte djto tuydn, bao gdm BGP (Border Gateway Protocol), OSPF (Open Shortest Path First), IS-IS (Intermediate System to
Intermediate System) vd cdc chftc ntog cua chuydn maeh toto da 0ao thfte (MPLS) hd bp cdc dich vu tou mang ridng ao (VPN) ldp 3 vd eac dich vu LAN ridng do (VPLS). Ddng thdi, mang Idi IP edn hd bp djto tuydn P. Cdc bO dito tuydn P kdt ndi tdi mdt hode nhidu bd djto tuydn PE. Chtog boat dOng tou mOt bO djto tuydn chuydn maeh toto I^R (Label Switch Router), chju ttach nhidm chuydn maeh cdc tota dupe su dung dd dito tuydn cdc gdi to tai ede nut bd djto tuydn trung 0an tdi cdc dich cudi etog eiia chtog.
Trdn thuc td, cdc chuc ntog dito tuydn PE vd P dupe tildn khai ttpng etog mdt hd thdng, gpi ehung
TAP CHi CNTT&TT KY 1 (9.2012) 2 7
CONG NGHE V I £ N THONG
Service routers Internet
IP-VPN L2VPN access VoIP IPTV
SONETT transport
Private line services
IP peering (comcost
\P T
19 M • Vw f^
pA Transport neti*ork (OT^/WDM) : Wholesale bandwidth
Typical core / backbone network
Hlnh 1: Mang da kip: cdc bO dinh tuygn dich vu, bO djnh t u y ^ 101 va mang truydn tdi
Id "bO djto tuydn Idi'. Vide tieh hpp ndy ldm ttog chi phi ddi vdi ede bO djto tuydn ed bO tod Ita, hd ttp xu ly gdi d tdc dd cao vd thue hiOn ldp Ueh da mftc phftc tap. Mdt khdc, ttong hdu hdt cdc mang IP, mOt gdi to truydn ttong mang tft ngudn tdi dich thutag phdi di qua nhidu bO dito tuydn trung 0an.
Vi vdy, mOt ty Id Ito cdc gdi to truydn qua bO djto tuydn ehi don 0 t o Id ehuydn tidp qua nut dd, ndn ehi ydu cdu thiic hidn ehuydn maeh MPLS thay vi sft dung bd djto tuydn PE ddt tidn.
Trong khi dd, ldp WDM ndm dudi ldp IP thue hidn vai bd cung edp Udn kdt ndi 0aa cdc bO dito tuydn Idi bong mang IP ddi vdi totog khotog cdch Ita vd hd ttp tiuydn tai da djch vu, bao gdm SONET/
SDH, mang luu trft SAN, Carrier Ethernet.... Hidn nay ttong nhidu hd thdng mang, ldp truydn tdi dang dupe chuydn ddi sang mang truydn tal quang OTN (Optical Transport Network) dd cung cdp da djch vu vdi khd ntag khdi phuc djch vu vd edu hito lai Uto hoat hon.
Do dd vide tdi im hda Wdn trie da ldp (Multi-
Layered architecture) thay vi chi tdi uu hda ttog Idp 0up 0am thidu dtog kd chi phi co sd ha ttag mang. Qua dd, 0ftp cae tod mang 0am thidu dp lue vd vide ttog doato thu vd Ipi touto khi chi phi ddu tu thidt bj vd vto hdto mang 0dm. Ngodi ra, mang tieh hpp da ldp edn 0iip cdc tod mang dua ra cdc gdi sto pham vd djch vu mdi toato ehdng vd don 0 t o bong mdi trutag cato b a t o khde Udt hidn nay.
Mang tieh hpp da ldp dat dupe totog muc tidu bdn btag each tdp trung vdo vide hdi tu thue su eho cac Idp mang dd ha thdp chi phi xdy dung vd vta hdto cdc mang truydn thdng.
Nhd vide tich hpp cdc chftc ntog cua cdc ldp mang (IP, MPLS, WDM, OTN) vdo ctog mOt ndn ttog duy todt, cae tod cung edp dich vu vidn thOng cd thd ha thdp chi phi ddu tu ban ddu, chi phi hoat ddng vd ehi phi ttdn ttag bit dft Udu. Hito 1 mito hpa Wdn tnie mto9 ta Idp didn hito.
Vdi Wdn tnic mang ndy, nhd khai thdc co thdm nhidu co hdi dd cdt giam chi phi mang tod:
2 8 I TAP CHi CNTT&TT KY 1 (9.2012)
Gidm ede Udn kdt ndi 0fta cdc Idp IP vd WDM ctog tou cdc 0ao didn cd Udn quan bong mdi Idp.
• Gidm sd lupng cdc budc tody bO dito tuydn.
• Gidm sd lupng ede cdng bO dito tuydn dupe su dung ndi chung bong cdc bO dito hiydn PE hode P.
MO H I N H K I E N TRUC MANG T I C H HQ^P S A L O P
Kien t r u e m^ng t i c h h^p hai ldp
Mdt Wdn true don gito dupe dd xudt eho hOi ti^
quang gdi Id IP bdn WDM (IPoWDM), todm muc tidu Idm 0dm sd Udn kdt ndi 0fta cdc ldp IP vd WDM btag cdch chuydn ddi 0ao didn WDM true tidp vdo bO djto tuydn. Vi vdy, bd djto tuydn Idi kdt ndi qua mdt mang ehuydn maeh budc sdng md khdng cto Idp ehuydn maeh OTN trung 0an ctog tou totog thay ddi tdi kdt ndi hode cdu hito mang IP, 0iip tidt Wdm chi phi ddu tu vd khai thdc.
MOt tidp cto khde eho hOi tu quang gdi Id chia tdch cdc bO djto tuydn Idi thdto hai ndn ttag ridng. 6 ddy, cdc bd djto tuydn PE hd ttp ede djch vu kdt ndi IP vd tdch ede bd djto tuydn P khdi chuydn maeh LSR ndm 0fta mang MPLS, do dd khdng cto su dung cdc bd djto tuydn 101 ddt tidn hd bp tito ntog PE md thay vdo dd Id cdc
bd djto tuydn P ed chi phi thdp hon tal cdc nftt trung 0an.
Trong trutag hpp ndy, cdc bd djto tuydn P ctag cd thd su dtog thdto phto quang WDM tieh hpp, tildn khai MPLS ttdn WDM (MPLSoWDM).
Cd IPoWDM vd Hlnh 2: Ki6n tnic P/MPLS-over-OTN/WDM
MPLSoWDM ddu ldm 0am sd kdt ndi 01ia cdc Idp vd ttong tirong lai MPLSoWDM edn hua hpn cdt 0am chi phi cua ehuydn maeh MPLS. Tuy nhidn vide su dung cdc 0ao didn WDM tieh hpp bong cdc bO djto tuydn PE bode P ctog dem lai mOt sd ban ehd. Do edu hlto bO dito tuydn vta 0ft nguydn ndn khdng ldm 0am sd lupng edng bO dito tuydn. Cudi ctog, tidp cto ndy khdng cd hidu qua bong viOc hd bp mang da djch vu.
Kien true m^ng tieh h^p da I6p IP/MPLS t r d n OTN/WDM
MOt hutag tidp eta khde dd tich hpp da ldp Id tich hpp truydn tai WDM, ghdp kdto OTN vd ehuydn maeh MPLS thdto mOt ndn ttog gdi hOi tu duy todt.
Thuc ehdt ddy chito Id mang tich hpp ba ldp: IP/
MPLS bdn OTN/WDM (IP/MPLS over OTN/WDM), todm khdc phuc dupe totog ban ehd ciia Wdn tnic mang hai ldp (IP/MPLS-over-WDM). Bdi bong Wdn tnie hai Idp, cdc bd dito tuydn 101 dupe kdt ndi qua cdc dutag edp quang vd WDM eung cdp cdc kdto tmydn dta. Do do khi bd sung thdm budc sdng dd ttag thdm dung lupng cua mang dutag true thi se ddi hdi md rdng dung lupng cua ede bO djto tuydn.
Tuy nhidn tiiue td cd khotog 60- 70% cdc bO djto tuydn ndy dupe sii dung chi dd ehuydn tidp luu lupng thay vi thue hiOn ghdp vd xen ludng tou chuc ntog chito eua nd. Cdn ddi vdi cdc mang tieh hpp da ldp IP/MPLS ttdn OTN/WDM, ldp OTN duoc coi tou Idp 0iia tdch ridng cdu hlto Io0c vd vdt ly (Hito 2). Cdc bO djto tuydn IP/MPLS Layer
OTN Layer
WDM Layer
TAP CHi CNTT&TT KY 1 (9.2012) 2 9
CONG NGHE V I £ N THONG
P r e i « n t n i o d e of o p e r a t i o n
P h a s e 1
Routing (IP)
Phase 2
Routing (IP) Routing ([P/MPI£)
Switching (MPLS) ^
Converged MPLS + OTN switching + WDM Switching
IVanspon
Hlnh 3: cac tuy chgn tri^i khai mang mang tich hqD da lOp P/MPLS over OTN/WDM dSi v6i cdc nha cung Cei3 djch vg
IP/MPLS se dupe kdt ndi dua ttdn edu hito Io0c cdn OTN/WDM cimg cdp cdc kdt ndi dua ttdn cdu hito vdt ly. Kdt qua Id khi dich vu ydu edu nhidu hon mdt kdt ndi lo0c tai ldp IP/MPLS ed thd dupe eung edp bdi mOt sd lupng kdt ndi it hon tai ldp OTN/WDM. Qua dd, ldm 0am dtog kd cdc dich vu chuydn tidp md bd djto tuydn Idi phai thue hidn.
Nhu vdy, mang tich hpp da Idp IP/MPLS ttdn OTN/
WDM vfta chc phdp bO dito tuydn 0am tai btag cdch sii dung ehuydn maeh MPLS, vua eung edp btag thdng hidu qua vd don 0 t a boat ddng btag cdch su dung ehuydn maeh OTN, ddng thdi dam bao md rdng btag thdng vdi WDM.
Vide tridn khai mang tieh hpp da Idp IP/MPLS ttdn OTN/WDM ed thd thuc hidn theo ttag 0ai doan thdng qua vide 0di thidu ttog butie chuc ndng mang hOi tu (Hito 3). Trong dd budc ddu tidn Id hdi tu ciia ehuydn maeh OTN vd Oruydn tai WDM vdo mdt ndn ttog tich hpp duy todt, eho phep ede tod khai thdc thidt ldp CO ehd trung kd bo qua bd djto tuydn 0fta
PE/P bode 0fta ede bd djto tuydn P btag cdeh sii dirng cdc 0ao didn phu hpp vd btag thdng vd hidu qua vd Wto td todt.
Chuydn maeh OTN cho phep thidt ldp vd cdu hito lai toato ehdng tft xa, dOe ldp vdi cdc rtog buOc vd ky thudt quang, do dd cho phep don 0 t o hda boat ddng. Trong khi do, tich hpp chftc ntog WDM eho phdp ghdp kdto tdt ea cac trung kd bO dito tiiydn vdo cdc budc sdng 100 Gbps hay 500 Gbps. Do dd tdi da hda dung lupng va khd ntog mo rdng mang WDM. Chuydn maeh OTN etog dd dtog thich tog vdi eac quy trito khai thdc, vta hdto OSS/BSS hidn tai eua tod cung cap djch vu vd eung cdp kha ntag du dota, gidm sdt biOu ntag etag tou dd to cdy md cdc tod cung edp djch vu mong dpi.
Cudi etag, ede bd thdng mang tich hpp da Idp IP/MPI£
ti*n OTN/WDM cd thd tich hpp thdm ehuydn maeh LSR d trung tdm mang MPLS true tidp vdo ldp quang gdi hOi tu, ndm ngang hang vdi cdc bO dito tuydn PE dupe tridn
3 0 I TAP CHI CNTT&TT KY 1 (9.2012)
khai d bidn ciia mang IP vd hd ttp mdt loat cdc dich vu IP, cho phdp tidt WOm chi phi mang btag edeh tich hpp cdc chftc ntag bd dito hiydn P cto thidt vdo bO djto tuydn LSR.
KET LUAN
Ndn ttog mang tich hpp da Idp IP/MPLS ttdn OTN/
WDM eho phdp loai bd hdng ttdm, thdm ehi htog ngto spi quang thutog dupe su dimg eho kdt ndi ttong m?ing. Nd etog 0iip loai bd ede bd djto tuydn trung 0an dd tdi uu hda chi phi ddu tu bO 6inb tuydn. Vide xem xdt vd tridn khai ede tidp eto mang tich hpp da ldp 0up cdc tod khai thdc cd thd tdi uu hda qud trito ntog cdp mang, todm md rOng quy mO, hd ttp thdm cdc dich vu mdi, dd ddp tag tou
edu phdt tridn tuong lai eiia mito.
Tai lif u tham ichao
[1]. MELLE, S., G. BENNETT, C. UOU, C. VILLAMIZAR, AND V. VUSIRIKALA, "Ali&i Wavelength Transport: An Operational and Economic Analysis," (^t\ca\ Fiber Communications/National Rber Optic Engineers Conference, Session NThF2, Anaheim, 0 \ , March 22-27, 2009.
[2].K0MPELLA,K.,ANDP.BEL0Tn, 'Transport netwod<s at a Crossroads: The roles of MFtS and OTN In multilayer networks,"
Optical Fiber CIommunications/Naticnal Fiber Optic Engineers Conference, Session OTuG, Anaheim, CA, March 6 , 2 0 1 1
[3]. MELLE, S., D. PERKINS AND C. VILLAMIZAR, "Network Cost Savings from Router Bypass in Pover WDM Core Networks,"
Optical Fiber Communications/National Fiber Optic Engineers Conference, Session NTiD, Anaheim, CA, Feb. 2 4 - 2 8 , 2 0 0 8
