rfc3387.Considerations from the Service Management

NetworkWorkingGroupM.EderRequestforComments:3387H.ChaskarCategory:InformationalNokiaS.NagSeptember2002ConsiderationsfromtheServiceManagementResearchGroup(SMRG)onQualityofService(QoS)intheIPNetworkStatusofthisMemoThismemoprovidesinformationfortheInternetcommunity.ItdoesnotspecifyanInternetstandardofanykind.Distributionofthismemoisunlimited.CopyrightNoticeCopyright(C)TheInternetSociety(2002).AllRightsReserved.AbstractTheguidingprinciplesinthedesignofIPnetworkmanagementweresimplicityandnocentralizedcontrol.Thebesteffortserviceparadigmwasaresultoftheoriginalmanagementprinciplesandtheotherwayaround.Newmethodstodistinguishtheservicegiventoonesetofpacketsorflowsrelativetoanotherarewellunderway.However,asIPnetworksevolvethemanagementapproachofthepastmaynotapplytotheQualityofService(QoS)-capablenetworkenvisionedbysomeforthefuture.ThisdocumentexaminessomeoftheareasofimpactthatQoSislikelytohaveonmanagementandlookatsomequestionsthatremaintobeaddressed.1.IntroductionSimplicityaboveallelsewasoneoftheguidingprinciplesinthedesignofIPnetworks.However,asIPnetworksevolve,theconceptofserviceinIPisalsoevolving,andthestrategiesofthepastmaynotapplytothefull-serviceQoS-capablenetworkenvisionedbysomeforthefuture.WithintheIPcommunity,theirexistsagooddealofimpetusfortheargumentthatifthepromiseofIPistobefulfilled,networkswillneedtoofferanincreasingvarietyofservices.ThedefinitionofthesenewservicesinIPhasresultedinaneedforreassessmentofthecurrentcontrolmechanismutilizedbyIPnetworks.Effortstoprovidemechanismstodistinguishtheservicegiventoonesetofpacketsorflowsrelativetoanotherarewellunderway,yetmanyofthesupportfunctionsnecessarytoexploitthesemechanismsarelimitedinscopeandacompleteframeworkisEder,et.al.Informational[Page1]RFC3387IPServiceManagementintheQoSNetworkSeptember2002non-existent.Thisiscomplicatedbythefactthatmanyofthesenewserviceswillalsodemandsomeformofbillingframeworkinadditiontoacontrolone,somethingradicallynewforIP.Thisdocumentintendstoevaluatethenetworkandservicemanagementissuesthatwillneedtobeaddressed,iftheIPnetworksofthefuturearegoingtooffermorethanjustthetraditionalbesteffortserviceinanykindofsignificantway.2.BackgroundThetaskofdefiningamanagementframeworkforQoSwillbedifficultduetothefactthatitrepresentsaradicaldeparturefromthebesteffortservicemodelthatwasatthecoreofIPinthepast,andhadacleardesignstrategytohavesimplicitytakeprecedenceovereverythingelse[1].ThisphilosophywasnowheremoreapparentthaninthenetworkandservicemanagementareaforIP[2].ProposedchangestosupportavarietyofQoSfeatureswillimpacttheexistingcontrolstructureinaverydramaticway.CompoundingtheproblemisthelackofunderstandingofwhatmakesupaserviceinIP[3].Unlikesomeothernetworktechnologies,inIPitdoesnotsufficetolimitthescopeofservicemanagementsimplytoend-to-endconnectivity,butthetransportserviceofferedtopacketsandthewaythetransportisusedmustalsobecovered.QoSmanagementisasubsetofthemoregeneralservicemanagement.InlookingtosolvetheQoSmanagementproblemitcanbeusefultounderstandsomeoftheissuesandlimitationsoftheservicemanagementproblem.QoScannotbetreatedasastandaloneentityandwillhaveitsmanagementrequirementsdrivenbythegeneralhigherlevelservicerequirements.IftheavailabletransportservicesinIPexpand,theresultwillbethefurtherexpansionofwhatisconsideredaservice.Thenowde-factoinclusionofWEBservicesinthescopeofIPservice,whichisremarkablegiventhattheWEBdidnotevenexistwhenIPwasfirstinvented,illustratesthissituationwell.Thisphenomenoncanbeexpectedtoincreasewiththecurrenttrendtowardsmovingnetworkdecisionpointstowardstheboundaryofthenetworkand,asaresult,closertotheapplicationsandcustomers.Additionally,theargumentcontinuesovertheneedforQoSinIPnetworksatall.Newtechnologiesbasedonfiberandwavelength-divisionmultiplexinghavemanypeopleconvincedthatbandwidthwillbesoinexpensiveitisnotgoingtobenecessarytohaveanexplicitcontrolframeworkforprovidingQoSdifferentiation.Howeveruneconomicalitistoengineeranetworkforpeakusage,amajorargumentinthisdebatecertainlyisthecostofdevelopingoperationalsupportsystemsforaQoSnetworkanddeployingthemintheexistingnetworks.JustthefactthatcustomersmightbewillingtopayforadditionalservicemaynotbejustificationforimplementingsweepingarchitecturalchangesthatcouldseriouslyaffecttheInternetasitisknownEder,et.al.Informational[Page2]RFC3387IPServiceManagementintheQoSNetworkSeptember2002today.TheIPcommunitymustbeveryconcernedthattheequalitythatcharacterizedthebesteffortInternetmaybesacrificedinfavorofaservicethathasacompletelydifferentbusinessmodel.Ifthecorenetworkstartedtoprovideservicesthatgeneratedmorerevenue,itcouldeasilycomeattheexpenseofthelessrevenuegeneratingbesteffortservice.3.IPManagementStandardizationManagementstandardizationeffortsintheIPcommunityhavetraditionallybeenconcernedwithwhatiscommonlyreferredtoaselementmanagementordevicemanagement.Recently,neweffortsinIPmanagementhaveaddedtheabilitytoaddressserviceissuesandtolookatthenetworkinmoreabstractterms.Theseeffortswhichincludedalogicalrepresentationofservicesaswellastherepresentationofresourcesinthenetwork,combinedw