实现diffserv qos模型分类标记简介识别流量归类过程通常基于模块3 ont10s04l01.pptx

ImplementtheDiffServQoSModelIntroducingClassificationandMarking

Classification

ClassificationClassificationistheprocessofidentifyingandcategorizingtrafficintoclasses,typicallybasedupon:inginterfaceIPprecedenceDSCPSourceordestinationaddressApplicationClassificationisthemostfundamentalQoSbuildingblock.Withoutclassification,allpacketsaretreatedthesame.

Marking

MarkingMarkingistheQoSfeaturecomponentthat“colors”apacket(frame)soitcanbeidentifiedanddistinguishedfromotherpackets(frames)inQoStreatment.Commonlyusedmarkers:Linklayer:CoS(ISL,802.1p)MPLSEXPbitsFrameRelayNetworklayer:DSCPIPprecedence

ClassificationandMarkingattheLinkLayer

ClassificationandMarking

intheLANwithIEEE802.1QIEEE802.1puserpriorityfieldisalsocalledCoS.IEEE802.1psupportsuptoeightCoSs.IEEE802.1pfocusesonsupportforQoSoverLANsand802.1Qports.IEEE802.1pispreservedthroughtheLAN,notendtoend.

ClassificationandMarkingintheEnterprise

DiffServModel

DiffServModelDescribesservicesassociatedwithtrafficclasses.Complextrafficclassificationandconditioningisperformedatthenetworkedge,resultinginaper-packetDSCP.Noper-flowstateinthecore.ThecoreonlyperformssimplePHBsontrafficaggregates.ThegoaloftheDiffServmodelisscalability.Widevarietyofservicesandprovisioningpolicies.Decoupleserviceandapplicationinuse.Noapplicationmodification.Nohop-by-hopsignaling.Interoperabilitywithpliantnodes.Incrementaldeployment.

IPPrecedenceandDSCPCompatibility

IPPrecedenceandDSCPCompatibilityCompatibilitywithcurrentIPprecedenceusage(RFC1812)Differentiatesprobabilityoftimelyforwarding:

(xyz000)=(abc000)ifxyzabc

(thatis,ifapackethasDSCPvalueof011000,ithasagreaterprobabilityoftimelyforwardingthanapacketwithDSCPvalueof001000)

PerHopBehaviors

Per-HopBehaviorsDSCPselectsPHBthroughoutthenetwork:DefaultPHB(FIFO,ta