Advanced(Computer( Networks

Transcription

1 dvned(omputer( Networks ontents! ((Multi(Protool(Lel(Swithg)! Lel(swppg! Elements(of(! Lel(swithg! Lel(distriution! Intertion(with(IGP! Trffi(engeerg Prof.(ndrzej(Dud Prolems(with(TM(tegrtion! IGP(limits! very(lrge(rg(tles((the(ore(network! for(every(pket(look(up(more(tht(((entries(! forwrdg(from(the(isp(pot(of(view(l just(fd(the(egress( rer! IP(rg(my(ignore(the(rel(physil(topology(! ISP(n(put((rer(on(the(edge(nd(use(TM/Frme(Rely( Virtul(Pth,(swithes((the(middle! edge(rer(selets(the(pth(sed(on(the(desttion(ddress(! re(look(up(done(only(one((the(isp(network(! ut(still(slility(prolems( IP#over#TM#VPs! TM(loud(visile(to( Lyer(3(Rg! Full(mesh(of(Vs(with( TM(loud(L n(nl)/ IP#over#! TM(network(visile(to( Lyer(3(Rg! Sgle(djeny(possile( with(edge(rer (elimtes(the( nlsqured prolem(of(ip(over(tm(vps 3 4! More(IGP(limits! SPF(lgorithms(send(trffi(on(shred(pth(nd(my(ignore( unloded(lks! even(if(lod(lng(n(e(done((some(ses((igrp)! TM(or(FR(n(use(virtul(iruits,(ut(PPP/SD/DWDM(does( not(! Gols(of(! rese(forwrdg(performne! provide(more(flexiility(thn(igp(rg! expliit(rg,(qos rg! kup(res,(lod(lng,(vpn! multiprotool(l (unifyg(view(t(.5(lyer(l (unified(wy(of( ontrollg(the(underlyg(lyer((network! TM,(FR,(PPP,(SD/DWDM TM(VPI/VI(swithg TM(ells heder(onts(vpi/vi 9 VPI/VI VPI/VI

2 Lel(swppg (elements D Ingress(LER((Lel(Edge(Rer) LSR((Lel(Swith(Rer) Egress(LER((Lel(Edge(Rer) V(tle(t(: VPI/VI VPI/VI Virtul(iruits(opened(( the(followg(order: 4 3 D 7 sr dst * 8.78/5 /7 8/8 9.88/6 /8 FE(L Lel(Mppg d FE xxx /7 /5 yyy /8 d/33 LSP((Lel(Swithed(Pth) 8.78/5 9.88/6 FE((Forwrd(Equivlene(lss) LI((Lel(Informtion(se) 8 (Priples! Lels! gress(ler(lssifies(pkets(to(identify(fe(tht(determes( (lel(serts(the(lel((3(its)! LSR(swithes(sed(on(the(lel(! lel(swppg(l lel(hs(meng(lol(to(one(lsr( (requires(lel(distriution(protool)! egress(ler(removes(the(lel! LSR! onts(li(l swithg(tle(tht(determes(the(pth(( the(network((lsp)! LSP(L similr(to((tm/fr(virtul(iruit! hnge(of(the(forwrdg(prdigm! sted(of(hop(y(hop! LSP(determed(t(entry((funtion(of(FE,(soure,(or(other 9 Forwrdg(Equivlene(lsses! FE(L group(of(ip(pkets(! forwrded((the(sme(mnner,(over(the(sme(pth,(nd( with(the(sme(forwrdg(tretment(! FE(my(orrespond(to(! desttion(ip(sunet! soure(nd(desttion(ip(sunet(! trffi(lss(tht(ler(onsiders(signift(! For(exmple,(ll(trffi(with((ert(vlue(of(IP( preedene(my(onstitute((fe! FE((our(exmples! IP(prefix Forwrdg(Equivlene(lsses (Enpsultion(L PPP(&(LN IP LER IP LSP L L LSR IP LSR Pkets#re#dested#for#different#ddress# prefixes,#ut#n#e mpped#to#ommon#pth L L IP L3 L3 LER IP Lyer##eder (eg.#ppp,#8.3) Lel#Stk Entry#Formt # Shim eders#(sn) n 4#Otets Network#Lyer#eder nd#pket#(eg.#ip) Lel Exp. S TTL Lel:## Lel#Vlue,##its Exp.:# Experimentl,#3#its#(ws#lss#of#Servie) S: ottom#of#stk,###it###(#=#lst#entry##lel#stk) TTL: Time#to#Live,#8#its! FE(=( (suset(of(pkets(tht(re(ll(treted(the(sme( wy(y((rer! onventionl(rg:((pket(is(ssigned(to((fe(t( eh(hop((i.e.(l3(looklup),(((it(is(only(done(one(! (on(ppp(lks(nd(lns(uses(shim(heder! serted(etween(lyer((nd(3(heders t(the(network(gress

3 (Enpsultion(L TM (exmple TM#eder Formt TM SR TM#eder TM##Pylod Option# Option# Option#3 n 5#Otets VPI VI PT LP E Generi#Lel#Enp. (PPP/LN#formt) 48(ytes Lel 48(ytes ( ( Lel omed#lel TM#VPI#(Tunnel) Lel L#5#PDU#Frme#(nx48#ytes) Network#Lyer#eder nd#pket#(eg.#ip) L5#Triler! Top((or((lels(re(onted((the(VPI/VI(fields(of( TM(heder! one((eh(or(sgle(lel((omed(field,(negotited(y(ldp! Further(fields((stk(re(enoded(with( shim heder( sr dst * 8.78/5 /7 * 9.88/6 /7 sr dst * 9.88/6 /8 * 8.78/5 /8 8/8 9.88/6 / (PPP/LN(formt 3 4 d /7 /5 d/8 /5 d/3 /33 /5 /77 /33 /37 FE(skipped((LI /77 pop /37 pop /5 9.88/6 Lel(Distriution(Protool((LDP) Lel(distriution(ensures(tht(djent(rers(hve (ommon(view(of(fe(<d>(lel(dgs Rg(Tle: ddrdprefix((((next(op 47.../8((((((LS IP(Pket Lel(Informtion(se: LelDIn(((((FE(((((LelDOut XX((((((((((47.../8((((((7 Step#3:##LSR#serts#lel vlue#to#forwrdg#se Rg(Tle: ddrdprefix((((next(op 47.../8((((((LS LS LS LS For(47.../8 use(lel( 7 Step#:##LSR#ommunites dg#to#djent#lsr Lel(Informtion(se: LelDIn(((((FE(((((LelDOut 7((((((((((47.../8(((((((XX Step#:##LSR#retes#dg etween#fe#nd#lel#vlue ommon%understndg%of%whih%fe%the%lel%is%referrg%to! Lel(distriution(n(either(piggyk(on(top(of(n(existg(rg(protool, or((dedited(lel(distriution(protool((ldp)(n(e(reted. 5 Lel(distriution! Lel(distriution(is(lwys(done(from(downstrem(to( upstrem! downstrem+unsoliited:( new(re(=>(send(new(lel LS(( LelLFE(dg LS(((! downstrem+on+demnd:( upstrem(lsr(sks(for((lel LS Request(for(dg LelLFE(dg LS 6 Lel(retention Lel(ontrol LS((( X LS LS((( LS Vlid(NextLop LS(( Vlid(NextLop LS Lierl onservtive! Lel(retention(n(e! lierl:( (memorize(ll(lels(from(downstrem(lsr((fster)! onservtive:( memorize(only(seleted(lels((less(memory)( 7 Inomg Lel! Lel(ontrol(n(e Next(op (for(fe) Outgog Lel! ordered:( (LSR(only(ds(nd(dvertise((lel(for(( prtiulr(fe(if! it(is(the(egress(lsr(for(tht(fe(or! it(hs(lredy(reeived((lel(dg(from(its(nextlhop! LSP(formtion( flows from(egress(to(gress! dependent:( LSR(ds((Lel(to((FE(dependently,( whether(or(not(the(lsr(hs(reeived((lel(from(the(nextl hop(for(the(fe(! LSR(then(dvertises(the(lel(to(its(neighor! LSP(is(formed(s(omg(nd(gog(lels(re(splied( together 8

4 Lel(distriution Lel(distriution(exmple(L OSPF! Different(lel(distriution(protools! LDP((Lel(Distriution(Protool)! defed(for(! Extension(of(GP! Extension(of(RSVP! RSVPLTE:(trditionl(RSVP(+(Expliit(Re! RLLDP((onstrtLsed(LDP)! LDP(+(Expliit(Re,( (L IP(prefix M. (L IP(ddress,( (L terfe /LL/L3(L LI(entry, M, N, O M. O. N. M. T. P., M, T 9, N, P OSPF(L rg(tles Lel(dgs O: lol M: lol N: lol : O. : M. : T: M. P: M. O. N. N: lol P: lol : P. : N. : N. T: N. M: N. O: N. M. T. P. M: lol T: lol : T. : M. : M. N: M. P: M. O: M. : /L, /L : /L3, /L4 : /L5, /L6, -/pop M : /L7, /L8, -/pop N : /L9, /L, -/pop O : /L, /L, -/pop P : /L3, /L4 T : /L5, /L6 M. O. N. : /L7 : /L8, -/pop : /L9 M : /L N : /L, -/pop O : /L P : /L3, -/pop T : /L4 M. T. P. : /L5, -/pop : /L6 : /L7 M : /L8, -/pop N : /L9 O : /L3 P : /L3 T : /L3, -/pop Swithg(tles LDP(Protool( UDPLello : /L : /L4 : -/pop M : -/pop N : -/pop O : -/pop P : /L4 T : /L5 /L7-/L /L9--/pop /L--/pop /L--/pop /L4-/L5 /L6-/L4 /L7--/pop /L9--/pop /L3--/pop /L3-/L4 M. O. N. : /L7 : -/pop : /L9 M : /L N : -/pop O : /L P : -/pop T : /L4 M. T. P. /L4--/pop /L4--/pop : -/pop : /L6 : /L7 M : -/pop N : /L9 O : /L3 P : /L3 T : -/pop /L--/pop /L5--/pop 3 UDPLello TPLopen Initiliztion(s) Lel(request(for((FE Lel(dg:(FE(L Lel 4

5 ERLLSP(setup(usg(RLLDP Trffi(Engeerg(with( 6. When LER reeives lel mppg, the ER estlished.. Lel Request messge. It onts ER pth <,,D> LER#. Request messge proessed nd next node determed. Pth list modified to <,D> 5. LSR reeives lel to use for sendg dt to LER D. Lel tle updted 4. Lel mppg messge origtes. LSR# LSR# LER#D 3. Request messge termtes. Demnd D Trffi#engeerg#is#the#proess#of#mppg#trffi#demnd#onto##network Network Topology Ingress! Expliit(Re(setup ER Lel Swithed Pth! RLLDP(n(lso(e(used(to(reserve(resoures! pek(rte,(ommitted(rte,(urst(size Egress 5! Mximize(utiliztion(of(lks(nd(nodes(! Engeer(lks(to(hieve(required(dely! Spred(the(network(trffi(ross(network(lks,(mimize( impt(of(sgle(filure! Ensure(ville(spre(lk(pity(for(reLrg(trffi 6 Unifyg(forwrdg(prdigm G/MPλS( Optil#Lel#Swith Ethernet PPP (SONET,#SD) TM Frme Rely λ Rg# ontrol! (offers(n(endltolend(unifyg(forwrdg(prdigm! (is( multiprotool elow((lk(lyer)(s(well(s(ove( (network(lyer)! provides(for(onsistent(opertions,(engeerg(ross(multiple( tehnologies! llows(opertors(to(ontrol(different(tehnologies(((unified( mnner 7 λ λ λ n λ λ λ n Fri λ λ λ λ λ n λ λ λ n! Optil(networks(suh(s(DWDM! λ is(just(nother(lel(to(distriute(l no(new(protools(required 8 Fts(to(rememer! (llows(flexile(pket(lssifition(nd( network(resoures(optimiztion! Lels(re(distriuted(y(different(protools! LDP,(RSVP,(GP! Lels(hve(lol((LSR)(signife! no(need(for(glol((dom)(wide(lel( llotion/numerg! Different(lk(lyer(protools(my(oLexist((the( sme(lsr 9