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
ContentandContextAwareNetworkingUsingSemanticTagging
SethuramBalajiKodeswaran,AnupamJoshi
DepartmentofComputerScienceandElectricalEngineering
UniversityofMarylandBaltimoreCounty1000,HilltopCircle,Baltimore,MD21250Email:(kodeswar,joshi)@cs.umbc.eduAbstract
Today’smodelofnetworkingprimarilyconcentratesin-telligenceattheendhostswiththenetworkitselfoffer-ingasimple“best-effort”,“dataagnostic”communicationmedium.However,thisparadigmhasproventobeinsuf -cienttomeettodaysneedsconsideringthediversityofap-plicationsanddevicesthatarenetworked.Tooffervalueaddedservicestotheseendusersandapplications,moreandmoreintelligenceneedstobemigratedawayfromtheedgesandintothenetworkinacontrolledandtractablemanner.Inthispaper,wepresentourapproachofutilizingsemanticdatataggingtoprovidecontentlevelinformationfordatastreams owingthroughanetwork.Apolicybasedmanagementmechanismisutilizedwithinthenetworkfab-ricallowingrouterstoreasonoverthecontentandmakeintelligentdecisionsregardingthehandlingofdatapack-ets.Servicedifferentiation,in-networkcontentadaptation,traf cmonitoringandcontroletc.aresomeofthenewser-vicesthatcannowbeofferedbythenetworkinagenericand exiblemanner.Bydeployingourproposedarchitec-ture,anetworkneednolongerbeviewedasasimpledatatransportmediumbutratherasapolicy-controlledintelli-gentpacket/streamprocessorthatcanofferspecializedhan-dlingbasedonapplicationneeds.
presentourvisionofagenericand exibleframeworkthatenablestheincrementaldeploymentofintelligentservicesintothenetworkwiththeaimofoptimizingtheend-userexperiencefornetworkedapplications.Oneofthekeyen-ablersofthisapproachistoprovidenetworkrouterswithvisibilityintothetypeofdatathattheyarecarrying.Thiscontent-levelinformationcanthenbeusedbytherouterstomakemoreintelligentroutinganddatahandlingdeci-sions.Unlikeotherapproachessuchasactivenetworks,ourframeworkreliesonprovidingmetadataforthestreams,leavingtheactualdecisionmakingtotherouters,whicharecontrolledthroughrulesexpressedaspolicies.Apolicyen-forcerisbuiltintothearchitecturetoenforceruleswhichcaneitherbelocalorsystem-wide.Theserulesarespeci edbythenetworkprovidertocontroltraf c owsinthenet-work.Recentadvancesinnetworkprocessorspointtomoreandmoreprocessingpoweravailableatthenetworkrouters,andinmanycases,allowingforlimitedpacketprocessingatlinespeed.Further,industryinitiativessuchas[1]furthermotivatein-networkprocessingforspecializedhandlingofdatastreams.
Foranycontentlabelingsolutiontobeviableinalargescalenetwork,itmustbeboth exibleandgeneric.Havingaproprietarycontentlabelingschemedoesnotscalewellandforceseveryroutingentitytoknowhowtohandleeachcontentprovider’sindividuallabelingscheme.Forthisrea-son,wehavechosentouseRDF[3]asthemechanismtoconveythisinformation.Asdemonstratedinitsapplicationinthesemanticweb,RDF/RDFSisvery exible,genericandhasseenwidespreadacceptanceasadefactometa-datamarkupforwebcontent.ByutilizingRDF/RDFS(orOWLforschemade nition)asthemechanismtomarkup ows/packets,intermediaryintelligentroutingentitiescanusethismetadatatoreasonovertheirexistingknowledge-basetodeterminehowbesttohandleagiven ow.Inaddi-tion,inferencescanbemadetofurther“generalize”or“spe-cialize”agiven ow.Forexample,arouterthatcanpro-videspecializedhandlingforMPEG-4streamscanchoosetohandleaparticularpacketasthoughitwerepartofamul-
1Introduction
ThecurrentInternetwasoriginallydesignedtoprovide“best-effort”datatransportoverawiredinfrastructurewithendhostsutilizingalayerednetworkstacktoproviderelia-bility,qualityofservice,securityetc.foruserapplications.However,theproliferationofinelasticapplications,coupledwithwidespreadmigrationtowardshybridnetworksutiliz-ingwiredandwirelesslinksandtheplethoraofendhostvariantsrangingfromcellphonestoenterpriseserversne-cessitatesthemigrationofmoreandmoreservicesawayfromtheedgesandintothenetwork.Inthispaper,we