A Distributed Model forNextGeneration Router

Nextgeneration (NG)routers, characterized byhigh speedinterfaces, largeswitching capacity andpetabit packet processing spee,d haverecently beendeployed incorenetworks ofworldclass operators. Basedon distributed architectures, theserouters aredesigned withcontrol cardsandlinecards interconnected bya veryhigh-speed switch fabric, whereline cardscontain processing andmemoryresource allowing the sharing ofsomerouteprocessing taskswithcontrol cards. Thetraditional implementation modelofrouter software, where control cardsassumealltheprocessing tasks, istherefore no longerappropriate. Inthispaper,we proposea distributed modelforimplementing router software inordertofully exploit thehardwareplatform ofthenextroutergeneration, taking intoaccount theadditional capacity oflinecards. Themodel corresponds toa distributed architecture withcontrol cards acting assupernodesandlinecardsacting aspeers. Italso provides "direct" communication betweenlinecards, allowing themtocooperate insometaskprocessing without going through control cards. Suchamodelsignificantly increases therobustness, scalability andavailability ofrouters. We alsoinvestigate the proposed distributed modelinthecontext ofdifferent protocols supported byarouter, suchassignaling androuting protocols. Twocasestudies arepresented wherewediscuss theadvantages ofthedistributed modelforOSPFandLDP protocols.