Today’s model of networking primarily concentrates intelligence at the end hosts with the network itself offering a simple“best-effort”,“data agnostic ” communication medium. However, this paradigm has proven to be insufficient to meet todays needs co
thatarepermissible,thecrosslayerinteractionsarekepttractablewithoutmakingtheimplementationoverlyconvo-luted[21].
Alayer2LSP.
ADiffServawarenetwork. AnIntServawarenetwork.
ACoCoNetRouterFrameworkwillperformthenecessarymappingbasedonpolicy,contentandcontext.Forinstance,supposeapacketarrivesatarouterindicatingthatitre-quiresreliabletransfersemantics.Thedataplanechosentothenexthop,inthiscase,couldbeoveraTCPconnec-tion.Likewise,adatapacketindicatingthatitissensitiveinformation(telnetloginsforexample)butcurrentlynoten-cryptedcanberoutedtothenexthopoveranIPSECtun-nelordroppedifnoneisavailable(ifthatisthepolicy).WhereaCoCoNetRouterFrameworkrunsisveryimple-mentationdependent.Forexample,incaseofawirelessadhocnetwork,everyhostisarouterandhencecanpoten-tiallyruna(albeitsimpli ed)CoCoNetRouterFramework.Likewise,inanenterprisesetting,thehostmachineswithintheenterprisewilllikelyrunonlytheCoconetNodeFrame-workwithonlytheexteriorgatewayroutersrunningtheCo-conetRouterFramework.AnetworkserviceproviderwillmostlikelyhaveonlyedgeroutersruntheCoconetRouterFrameworkleavingthecoreoptimizedforfastdata owhandling.TheroleoftheGlobalPolicyDistributionPoint(GPDP)istodisseminateanynetworkwidepoliciesthatneedtobeenforced.Thiscanincludeitemssuchaspref-erentialtreatmentthatneedstobegiventocontentorigi-natingfromaparticulardomain,preferentialtreatmentforaparticulartypeofcontent,anycontentbasedadaptationtechniquesthatneedtobeemployedinthenetworketc.ItisenvisionedthattheGPDPiscontrolledbytheISPtosetforthglobalruleswhiletheLPDPhostedatanenterpriselocationispossiblysharedbetweentheISPandtheenter-prise.ThiscanfurtherbeextendedtosaythattheLDPDisunderlocalusercontrol(basedonuserpoliciesandpref-erences)andcanadditionally,hostuserpreferences.Inor-dertopropagatecontentlevelinformationforpacketsand ows,weproposetotakeoneofthefollowingapproaches. ThemetadatacanbedirectlyencodedintotheIPop-tions eldofanIPpacket(sizeisanissue).Werefertothisas“in-bandtagging”.
IPpacketsusetheIPoptions eldtocarryaspecial32bitidenti er.Thisidenti erisusedtoindicateawellknown(global)e-fulfornon- owbasedone-timepacketssuchastelnetloginorHTTPURLrequest.Werefertothisas“out-of-bandtagging”.
IPpacketsusetheIPoptions eldtocarryaspecialkey.Thiskeyislookedupinadirectoryservicetoidentifythemetadatadescribingthatpacketor ow.Thisisalso“out-of-bandtagging”.Usingastructured6
3.2Network
Level
Figure2.OverlayNetwork
Atthenetworklevel,weenvisionthattherewillbeanoverlaynetworkcomprisedofroutersthatruntheCoCoNetRouterFramework.ClientmachinesrunningourNodeFrameworkcommunicateoverthisoverlay.Theoverlaycomprisesoftwocomponents;
AcontrolplanecomponentthatinvolvesinteractionsbetweentheCoCoNetRouterLayersattheroutingel-ements.
Adataplanecomponentthroughwhichthedatapack-etsare owing.
OvertheCoCoNetRoutercontrolplane,routerscanex-changetraditionalmanagementinformationsuchaslinkstates,bufferlengthsetc.Inaddition,informationsuchascontenttypescurrentlybeinghandled,adaptationscurrentlyavailablecanbeadvertised.Anadditionalkeypieceofin-formationexchangedisthelocalpoliciesthatarecurrentlybeingappliedtoadatastreamthatisbeingrouted.LocalPEPsettingsforagivenstreamor owhaveglobalimpli-cations.Forexample,unlesseveryhopisreliable,adatapacketcannotbereliablyroutedthroughanetwork.Thedataplanecanbeimplementedaseither: AUDPconnectionbetweentworouters. ATCPconnectionbetweentworouters. AnIP-in-IPtunnelbetweentworouters.