2.1 Cng ngh IPTCP/IP l h giao thc cung cp cc phng tin lin kt cc mng nh vi nhau to ra mng ln hn gi l lin mng (Internetwork). Cu trc phn tng ca TCP/IP gm 4 tng: Lp lin kt d liu v vt l, lp IP, lp TCP/IP gm hai giao thc TCP (Tranmission Control Protocol) v UDP (User Datagram Protocol) trong TCP cung cp kh nng kt ni cn UDP cung cp kh nng phi kt ni, lp ng dng.

Hnh 2.1 Cu trc phn tng ca TCP/IP

Giao thc IP thc hin truyn thng tin di dng cc n v d liu gi l Datagram. C hai loi khun dng gi tin l IPv4 v IPv6, trong khi IPv4 ang tr ln li thi v bc l nhiu hn ch th s ra i ca IPv6 l mt bc pht trin tip theo trong cng ngh IP c th p ng cho cc yu cu mi.

Hnh 2.2 Truyn ti IP trong MEN

2.2 Cng ngh SDH/SDH-NG Cng ngh SDH hin ti l cng ngh truyn dn c p dng ph bin nht trong mng ca nhng nh cung cp dch v trn th gii. Cng ngh SDH c xy dng trn c s h thng phn cp ghp knh ng b TDM vi cu trc phn cp ghp knh STM-N cho php cung cp cc giao din truyn dn tc t vi Mbit/s ti vi Gigabit/s. c tnh ghp knh TDM v phn cp ghp knh ng b ca cng ngh SDH cho php cung cp cc knh truyn dn c bng thng c nh v c tin cy cao vi vic p dng cc cho ch phc hi v bo v, c ch qun l h thng theo cu trc t-p mng ph hp v c chun ha bi cc tiu chun ca ITU-T.

Hnh 2.3 Truyn dn Ethernet SONET/SDH T trc ti nay cng ngh truyn dn SDH c xy dng ch yu cho vic ti u truyn ti lu lng thoi. Theo nhng d bo v phn tch v th trng mng vin thng gn y, cc doanh nghip c s gia tng mnh m cc loi hnh dch v truyn d liu v c xu hng chuyn dn lu lng ca cc dch v thoi sang truyn ti theo cc giao thc truyn d liu (v d nh dch v thoi qua IP (VoIP).. Trong khi , cc c s h tng mng SDH hin c kh c kh nng p ng nhu cu truyn ti lu lng gia tng trong tng lai gn. Do vy yu cu t ra l cn phi c mt c s h tng truyn ti mi c th ng thi truyn ti trn n lu lng ca h thng SDH hin c v lu lng ca cc loi hnh dch v mi khi chng c trin khai. chnh l l do ca vic hnh thnh mt hng mi ca cng ngh SDH, l SDH th h k tip SDH-NG. Cc cng ngh to ra SDH-NG c tp hp chung trong mt khi nim l khi nim truyn d liu qua mng SDH DoS (data over SDH). DoS l c cu truyn ti lu lng cung cp mt s chc nng v cc giao din nhm mc ch tng hiu qu ca vic truyn d liu qua mng SDH. Mc tiu quan trng nht m cc hng cng ngh ni trn cn phi thc hin c l phi hp h tr ln nhau thc hin chc nng ci t/ch nh bng thng cho cc dch v mt cch hiu qu m khng nh hng ti lu lng ang c truyn qua mng SDH hin ti. iu ny c ngha l mng s m bo c chc nng h tr truyn ti lu lng dch v ca mng hin c v trin khai cc loi hnh dch v mi.

Hnh 2.4 M hnh giao thc trong SDH-NGThm vo , SDH-NG cung cp chc nng m bo cht lng dch v QoS vi mc chp nhn no cho cc loi hnh dch v mi; mm do v linh hot trong vic h tr truyn ti lu lng truyn ti bi cc giao thc khc nhau qua mng. C cu ca DoS bao gm 3 giao thc chnh: Th tc ng khung tng qut GFR (generic framing procedure) K thut lin kt chui o VC (virtual concatenation) C cu iu chnh dung lng ng thng LCAS (link capacity adjustment scheme). C 3 giao thc ny c ITU-T chun ho ln lt bi cc tiu chun G.7041/Y.1303, G.707, G.7042/Y.1305. Giao thc GFP cung cp th tc ng gi khung d liu cho cc dng lu lng khc nhau (Ethernet, IP/PPP, RPR, knh quang..) vo cc phng tin truyn dn TDM nh l SDH hoc h thng truyn ti quang OTN (optical transport network). Giao thc VC cung cp nhng th tc ci t bng thng cho knh kt ni mm do hn so vi nhng th tc p dng trong h thng truyn dn TDM trc . Giao thc LCAS cung cp th tc bo hiu u cui ti u cui thc hin chc nng iu chnh ng dung lng bng thng cho cc kt ni khi s dng VC trong kt ni SDH. u im ca SDH-NG Cung cp cc kt ni c bng thng c nh cho khch hng tin cy ca knh truyn dn cao, tr truyn ti thng tin nh. Cc giao din truyn dn c chun ha v tng thch vi nhiu thit b trn mng. Thun tin cho kt ni truyn dn im -im Qun l d dng Cng ngh c chun ha Thit b c trin khai rng riNhc im ca SDH-NG Cng ngh SDH c xy dng nhm mc ch ti u cho truyn ti lu lng chuyn mch knh, khng ph hp vi truyn ti lu lng chuyn mch gi. Do cu trc ghp knh phn cp nn cn nhiu cp thit b ghp tch, phn chia giao din n khch hng. Kh nng nng cp khng linh hot v gi thnh nng cp l tng i t. Khng ph hp vi t chc mng theo cu trc Mesh. Kh trin khai cc dch v ng dng Multicast Dung lng bng thng ginh cho bo v v phc hi ln Phng thc cung cp kt ni phc tp, thi gian cung ng kt ni di. 2.3 MPLS/VMPLS2.3.1 MPLSMPLS l mt cng ngh ng vai tr then cht trong cc mng th mc d cng ngh ny khng c thit k dnh ring cho th trng mng th.

Hnh 2.5 Truyn ti cng ngh MPLS trong MENNguyn l hot ng ch yu ca thc hin trong cng ngh MPLS l thc hin gn nhn cho cc loi gi tin cn chuyn i ti cc b nh tuyn nhn bin LER, sau cc gi tin ny s c trung chuyn qua cc b nh tuyn chuyn mch nhn ng LSR. Cc ng chuyn mch nhn LSP c thit lp bi ngi iu qun l mng trn c s m bo mt s yu cu k thut nht nh nh l mc chim dng ng thng, kh nng tc nghn, chc nng kin to ng hm.Nh vy, s hot ng chuyn mch cc LSP cho php MPLS c kh nng to ra cc kt ni u cui ti u cui nh i vi cng ngh ATM hoc Frame Relay v cho php truyn lu lng qua cc tin ch truyn ti khc nhau m khng cn phi b thm cc giao thc truyn ti hoc c cu iu khin phn lp 2. Nhng chc nng ch yu ca cng ngh MPLS c m t v nh ngha trong cc ti liu ca t chc IETF (RFC 3031, 3032). Phng php chuyn mch nhn ng dng trong cng ngh MPLS cho php cc b nh tuyn thc hin nh tuyn gi tin nhanh hn do tnh n gin ca vic x l thng tin nh tuyn cha trong nhn. Mt chc nng quan trng na c thc hin trong MPLS l thc hin cc k thut lu lng, cc k thut ny cho php thit lp cc ng thng cc thng s thc hin mng c th truyn ti lu lng vi cc cp dch v v cht lng dch v khc nhau (RFC 2702). Mt chc nng quan trong na c cung cp trong MPLS l kh nng kin to cc kt ni ng hm cung cp dch v mng ring o (VPN). Mng thc hin trn c s cng ngh MPLS cho php gim phc tp iu khin v qun l mng do vic truyn ti lu lng xut pht t nhiu loi hnh giao thc khc nhau. Cng ngh MPLS hin ti ang c pht trin theo hai hng: MPlS (Multi Protocol lamda Switching) v GMPLS (Generalized Multiprotocol Label Switching). MPlS tp trung vo xy dng ng dng truyn ti IP qua mng quang, c th l tm kim cc gii php chuyn ti lung lu lng IP vo cc bc sng quang. Trong khi GMPLS tp trung vo vic xy dng nn tng iu khin cho mng MPLS nhm tch hp chc nng qun l ca cc phng thc truyn ti khc nhau nh l IP, SDH, Ethernet trn mt nn tng qun l thng nht.u im MPLS c th p dng ph hp vi hu ht cc cu trc t-p mng (mesh hoc ring). MPLS cho php truyn ti a dch v vi hiu sut truyn ti cao. Chc nng iu khin qun l lu lng trong MPLS cho php truyn ti lu lng cc loi hnh c yu cu v QoS. MPLS cho php nh tuyn gi tin vi tc nhanh do gim thiu vic x l thng tin nh tuyn MPLS cho c kh nng kin to kt ni ng hm. Da trn kh nng ny nh cung cp dch v c th cung cp cc dch v kt ni o (v d nh TLS mc 2, VPN mc 3). MPLS c kh nng phi hp tt vi IP cung cp cc dch v mng ring o trong mi trng IP v kt hp vi chc nng RSVP cung cp dch v c QoS trong mi trng IP (RSVP-TE LSPs)Nhc im Kh nng hi phc mng khng nhanh khi xy ra s c h hng trn mng. Khi trin khai mt cng ngh mi nh MPLS i hi cc nhn vin qun l v iu hnh mng cn c o to v cp nht kin thc v cng ngh mi, nht l cc kin thc mi v qun l v iu khin lu lng trn ton mng. Gi thnh xy dng mng da trn cng ngh MPLS ni chung cn kh t.Kh nng ng dng Cng ngh MPLS ph hp cho vic xy dng mng vi mc tiu truyn ti dch v tch hp v t c hiu sut truyn ti cao, ngha l MPLS ph hp xy dng mng li (core). 2.3.2 VMPLS Mng ring o MPLS lp 3 (MPLS VPN)Kin trc mng ring o MPLS lp 3 da trn RFC 2547 bis, m rng mt s c tnh c bn ca giao thc cng bin (BGP) v tp trung vo hng a giao thc ca BGP nhm phn b cc thng tin nh tuyn qua mng li ca nh cung cp dch v cng nh l chuyn tip cc lu lng VPN qua mng li. Trong kin trc mng L3 MPLS VPN, cc thit b nh tuyn ca khch hng v ca nh cung cp c coi l cc phn t ngang hng. B nh tuyn bin khch hng CE cung cp thng tin nh tuyn ti b nh tuyn bin nh cung cp PE. PE lu ccthng tin nh tuyn trong bng nh tuyn v chuyn tip o VRF. MPLS VPN l mt dng thc thi y ca m hnh mng ngang hng (peer-to-peer). Mng ng trc MPLS VPN v cc vng ca khch hng s trao i thng tin nh tuyn lp 3.

Hnh 2.6 Cu trc mng MPLS VPNu im ln nht ca MPLS/VPN l lm n gin qu trnh vn hnh ca mng cho khch hng trong khi cho php nh cung cp dch v tng cc dch v, mi cho cc dch v gia tng, c li nhun.2.4 GMPLS MPLS c thit k cho cc dch v trong cc mng gi, nhng mt phin bn mi l GMPLS th li c pht trin cho cc mng ton quang, bao gm cc kt ni SONET/SDH, WDM v truyn trc tip trn si quang. GMPLS c kh nng cu hnh cc lung lu lng dng gi v c cc dng lu lng khc.GMPLS m ra kh nng t c s hp nht cc mi trng mng s liu truyn thng v quang. Tuy nhin, vn cn rt nhiu kh khn khi trin khai GMPLS trn cc mng lp t.

Hnh 2.7 Truyn ti GMPLSMPLS v phin bn m rng ca n c th ng vai tr l mt lp tch hp cho cc mng MAN nhm cung cp tnh thng minh v l mt lp keo kt dnh gia mng quang WDM pha di v lp dch v IP. Vi vai tr ny, n c th cung cp chc nng cung cp bng tn im-im, x l v qun l lu lng v khi phc dch v. Hiu qu hn, MPLS c th hot ng nh mt lp thit lp cho cc dch v hng kt ni.2.5 Gigabit EthernetCng ngh Ethernet c xy dng v chun ho thc hin cc chc nng mng lp ng d liu v lp vt l. Cng ngh ny h tr cung cp rt tt cc dch v kt ni im - im vi cu trc t-p mng ph bin theo kiu ring v hub and spoke. Vi cu hnh hub and spoke, trong cc mng c quan, khu vn phng thng trin khai cc nt mng l cc thit b Switch v cc thit b Hub. Nt mng ng vai tr l cng (gateway) kt ni kp (dual home) vi nt mng thc hin chc nng POP (Point Of Present) ca nh cung cp dch v to nn cu trc mng. Cch t chc mng ny xt v kha cnh kinh t l tng i t, b li mng c duy tr mng cao v c kh nng m rng, nng cp dung lng.

Hnh 2.8 Truyn ti Gigabit Ethernet theo cu trc RingMng t chc theo cu trc t-p ring c p dng nhiu v c tnh hiu qu v mt tit kim chi ph u t xy dng mng ban u. Tuy nhin, mt trong nhng yu im ca cu trc mng kiu ny l khng hiu qu khi trin khai thut ton nh tuyn phn on hnh cy (spanning-tree-algorithm); l mt trong nhng thut ton nh tuyn quan trng p dng trong mng Ethernet do nhng hn ch ca c ch bo v v dung lng bng thng hu hn ca vng ring. C th l thut ton nh tuyn phn on hnh cy trong nhiu trng hp s thc hin chn mt vi phn on tuyn trong ring, iu ny s lm gim dung lng bng thng lm vic ca vng ring. Mt im na l thut ton nh tuyn phn on hnh cy c thi gian hi t di hn nhiu so vi thi gian hi phc i vi c ch bo v ca vng ring (tiu chun l 50 ms). Gigabit Ethernet l bc pht trin tip theo ca cng ngh Ethernet, mt cng ngh mng c p dng ph bin cho mng cc b LAN (Local Area Network) hn hai thp k qua. Ngoi c im cng ngh Ethernet truyn thng, cng ngh Gigabit Ethernet pht trin v b sung rt nhiu cc chc nng v cc tin ch mi nhm p ng yu cu a dng v loi hnh dch v, tc truyn ti, phng tin truyn dn. Hin ti cc giao thc Gigabit Ethernet c chun ho trong cc tiu chun IEEE 802.3z, 802.3ae, 802.1w. Gigabit Ethernet cung cp cc kt ni c tc 100 Mbit/s, 1Gbit/s hoc vi chc Gbit/s v h tr rt nhiu cc tin ch truyn dn vt l khc nhau nh cp ng, cp quang vi phng thc truyn ti n cng (half-duplex) hoc song cng (full-duplex). Cng ngh Gigabit Ethernet h tr trin khai nhiu loi hnh dch v khc nhau cho nhu cu kt ni kt ni im - im, im - a im, kt ni a im... in hnh l cc dch v ng kt ni Ethernet ELS (Ethernet Line Service), dch v chuyn tip Ethernet ERS (Ethernet Relay Service), dch v kt ni a im Ethernet EMS (Ethernet Multipoint Service). Mt trong nhng ng dng quan trng tp hp chc nng ca nhiu loi hnh dch v kt ni l dch v mng LAN o VLAN (virtual LAN), dch v ny cho php cc c quan, doanh nghip, cc t chc kt ni mng t cc phm vi a l tch ri thnh mt mng thng nht.u im ca cng ngh Cng ngh Ethernet v Gigabit Ethernet c nhng u im ni bt l: Cng ngh Ethernet c kh nng h tr rt tt cho ng dng truyn ti d liu tc cao v c c tnh lu lng mng tnh t bin v tnh bng n. C cu truy nhp CSMA/CD cng ngh Ethernet cho php truyn ti lu lng vi hiu xut bng thng v thng lng truyn ti ln. Thun li trong vic kt ni cung cp dch v cho khch hng. Khng i hi khch hng phi thay i cng ngh, thay i hoc nng cp mng ni b, giao din kt ni. Theo thng k, c ti 95% lu lng pht sinh bi cc ng dng truyn ti d liu l lu lng Etheret. iu ny xut pht t thc t l hu ht cc mng truyn d liu ca cc c quan, t chc (mng LAN, MAN, mng Intranet) hin ti u c xy dng trn c s cng ngh Ethernet. S ph bin ca cng ngh Ethernet ti lp truy nhp s to iu kin rt thun li cho vic kt ni h thng vi tng thch cao nu nh xy dng mt mng da trn c s cng ngh Ethernet. iu ny s dn ti vic gim ng k chi ph u t xy dng mng. Mng xy dng trn c s cng ngh Ethernet c kh nng m rng v nng cp d dng do c tnh ca cng ngh ny l chia s chung tin ch bng thngtruyn dn v khng thc hin c cu ghp knh phn cp. Hu ht cc giao thc, giao din truyn ti ng dng trong cng ngh Ethernet c chun ho (h giao thc IEEE.802.3). Phn ln cc thit b mng Ethernet ca cc nh sn xut u tun theo cc tiu chun trong h tiu chun ni trn. Vic chun ho ny to iu kin kt ni d dng, tng thch kt ni cao gia cc thit b ca cc nh sn xut khc nhau. Qun l mng n gin Nhc im Nu ch xt cng ngh Ethernet mt cch c lp, bn thn cng ngh ny tn ti mt s nhc im sau y: Cng ngh Ethernet ph hp vi cu trc mng theu kiu Hub (cu trc t - p hnh cy) m khng ph hp vi cu trc mng ring. iu ny xut pht t vic cng ngh Ethernet thc hin chc nng nh tuyn trn c s thut ton nh tuyn phn on hnh cy (spanning-tree-algorithm); l mt trong nhng thut ton nh tuyn quan trng p dng trong mng Ethernet. C th l thut ton nh tuyn phn on hnh cy trong nhiu trng hp s thc hin chn mt vi phn on tuyn trong ring, iu ny s lm gim dung lng bng thng lm vic ca vng ring. Thi gian thc hin bo v phc hi ln. iu ny cng xut pht t nguyn nhn l thut ton nh tuyn phn on hnh cy c thi gian hi t di hn nhiu so vi thi gian hi phc i vi c ch bo v ca vng ring (tiu chun l 50 ms). Khng ph hp cho vic truyn ti loi hnh ng dng c c tnh lu lng nhy cm vi s thay i v tr truyn ti (jitter) v c (latency) ln. Cha thc hin chc nng m bo cht lng dch v (QoS) cho nhng dch v cn truyn ti c yu cu v QoSKh nng p dngCng ngh Ethernet c th ph hp trin khai cho vic xy dng lp mng li truy nhp, m bo thc hin chc nng thu gom dch v, tch hp dch v ti phn lp truy nhp ca mng. iu ny tnh kh thi do do tnh tng thch cao v giao din kt ni v cng ngh i vi khch hng v nh ni trn, mng Ethernet c trin khai hu ht i vi cc mng ni b. Vic p dng cng ngh Ethernet phn lp mng no cn ph thuc vo qui m, phm vi ca mng cn xy dng v cn ph thuc vo cu trc t-p mng c la chn ph hp vi mng cn xy dng.2.6 WDM WDM l cng ngh truyn ti trn si quang xy dng v pht trin t nhng nm 90 ca th k trc. WDM cho php truyn ti cc lung thng tin s tc rt cao (theo l thuyt dung lng truyn ti tng cng c th n hng chc ngn Gigabit/s). Nguyn l c bn ca cng ngh ny l thc hin truyn ng thi cc tn hiu quang thuc nhiu bc sng khc nhau trn mt si quang. Bng tn truyn ti thch hp ca trn si quang c phn chia thnh nhng bc sng chun vi khong cch thch hp gia cc bc sng ( c chun ha bi tiu chun G.692 ca ITU-T), mi bc sng c th truyn ti mt lung thng tin c tc ln (chng hn lung thng tin s tc 10Gbit/s). Do , cng ngh WDM cho php xy dng nhng h thng truyn ti thng tin quang c dung lng gp nhiu ln so vi h thng thng tin quang n bc sng.

Hnh 2.9 M hnh DWDM Hin nay cng ngh WDM c quan tm rt nhiu trong vic la chn gii php xy dng mng truyn ti quang cho mng th. Th trng thng mi xut hin rt nhiu cc sn phm truyn dn quang WDM ng dng cho vic xy dng mng MAN. Cc h thng WDM thng mi ny thng thng c cu hnh c th truyn ng thi ti 32 bc sng vi tc 10Gbit/s v c th trin khai vi cc cu trc t-p mng ring, ring/mesh hoc mesh.

Hnh 2.10 K thut lu lng xp chng

Cng ngh WDM cho php xy dng cc cu trc mng xp chng s dng cc t-p v cc kin trc khc nhau. V d, nh cung cp dch v c th s dng WDM mang lu lng TDM (nh thoi) trn SONET/SDH trn mt bc sng, trong khi vn trin khai mt cng ngh truyn ti d liu (chng hn nh GE over RPR) trn mt bc sng khc. Vic s dng WDM trong MAN l mt phng thc c hiu qu kinh t nht l khi cung trao i lu lng trn mng ln, ti nguyn v cp v si quang cn t. Tuy vy nu s dng cng ngh WDM ch n gin l ghp dung lng SONET/SDH hin ti vi cc ring ngang hng th thc t li khng tit kim c cc chi ph u t (v mi bc sng thm vo li i hi mt thit b u cui ring ti cc nt mng). Hn na vic qun l li tr nn phc tp hn khng c li trong vic cung cp dch v kt ni im - im. gii quyt nhng vn ny, cc nh sn xut cung cp cc thit b WDM cho mng MAN a thm mt chc nng mi cho php qun l lu lng mc quang. iu dn n s ra i ca mt th h cc MSPP WDM mi, y cng l mt loi sn phm mng MAN chnh. MSPP WDM c nhng ng gp quan trng nh: Lu lng c qun l im-im ti mc quang H tr c nhiu loi cng ngh v dch v, c loi hin c v tng lai Cung cp mt nn tng cho vic chuyn i sang mt cng ngh v cu trc mng mi, c bit l cng ngh v cu trc mng ton quang.

u im Cung cp cc h thng truyn ti quang c dung lng ln, p ng c cc yu cu bng n lu lng ca cc loi hnh dch v Nng cao nng lc truyn dn cc si quang, tn dng kh nng truyn ti ca h thng cp quang c xy dngNhc im Gi thnh thit b t.Kh nng ng dng ng dng ph hp cho nhng ni m mng cn thiu v ti nguyn cp/si quang, cn phi tn dung nng lc truyn ti ca si quang. Nng cp dung lng, thay th h thng truyn ti quang hin c ng dng cho nhng ni m cn dung lng h thng truyn ti ln (mng li, mng ng trc).

2.7 Cng ngh mch vng Ring RPRThng 12 nm 2000, IEEE thnh lp mt nhm nghin cu v cng ngh mng vng gi phc hi (IEEE 802.17) nhm a ra cc tiu chun cho giao thc RPR. RPR l mt dng giao thc mi phn lp MAC (Media Acces Control). Giao thc ny c p dng nhm mc ch ti u ho vic qun l bng thng v hiu qu cho vic trin khai cc dch v truyn d liu trn vng ring. Cng ngh RPR c s dng truyn ti cc gi s liu trn mng vng tc hng Gigabit/s.

Hnh 2.11 M hnh truyn ti RPR

Gii php ny s dng cc Router kt ni cap quang vi cng ngh mi RPR h tr IP hoc thm ch MPLS ap ng tt c cc dch v khc nhau. RPR l cng ngh ch o cho mng th th h mi ang c cc hng vin thng ln tp trung pht trin (50 nh sn xut thit b v chip - Cisco, Nortel, Siemens, Redstone, ). Cng ngh ny kt hp tnh u vit ca phng thc bo v ng nh cng ngh SDH cho php kh nng hi phc tuyn cc nhanh mc 50 ms trn c s hai phng thc: phng thc steering v phng thc wrapping. Cung vi kh nng nh a ch kt ni theo a ch (dng a ch MAC) v phn loi lu lng cho cht lng dch v nh cng ngh Ethernet lp 1. RPR s dng vng song hng gm hai si quang truyn ngc chiu nhau, c hai vng ng thi c s dng truyn d liu v iu khin. RPR cho php nh cung ng gim chi ph thit b phn cng cng nh thi gian gim st mng. Trong RPR khng c khi nim khe thi gian, ton b bng thng c n nh cho lu lng. Bng cch tnh kh nng mng v d bo yu cu lu lng, RPR ghp thng k v phn phi cng bng bng thng cho cc node trn vng trnh tc nghn c th mang li li ch hn nhiu so vi vng SDH/SONET da trn ghp knh phn chia theo thi gian. RPR l giao thc lp MAC vn hnh lp 2 ca m hnh OSI, n khng nhn bit lp 1 nn c lp vi truyn dn nn c th lm vic vi WDM, SDH hay truyn dn da trn Ethernet (s dng GBIC Gigabit Interface Converter) ngoi ra, RPR i t thit b a lp n dch v mng thng minh lp 3 nh MPLS, MPLS kt hp thit b ra mng IP lp 3 vi thit b lp 2 nh ATM, Frame relay. S kt hp tin cy v kh nng phc hi ca RPR vi u im qun l lu lng v kh nng m rng ca MPLS VPN v MPLS TE c xem l gii php xy dng MAN trn th gii hin nay.RPR tha k hai c trng quan trng ca mng SONET/SDH. C th kt ni theo cu hnh RING. C th khi phc ng truyn nhanh khi ng cp quang b t