IEEE8021Q.ppt

IEEE802.1Q,MediaAccessControlBridgesandVirtualBridgedLocalAreaNetworksPatriciaThaler,NormanFinn,DonFedyk,GlennParsons,EricGray,IEEE802.org/1,March10,2013,Authors,IEEE802.1Q,2,PresentationObjective,Giveanoverviewofthecapabilitiesoftodays802.1QItismuchmorethanspanningtreeprotocoland4KVLANsAlotoftopicscoveredatahighlevelOverallcapabilitiesarediscussedbutdetailsarenotcoveredTodaysnetworksofteninvolveamixtureofL3routingandL2bridgingsometimeseveninthesameboxUnderstandingoftodaysL2wouldbeuseful,IEEE802.1Q,3,Contents,IEEE802.1OverviewBridgearchitectureDataplaneProviderBridges(PB)/Q-in-Q/ProviderBackboneBridges(PBB)/MAC-in-MAC/EdgeVirtualBridging(EVB)ControlplaneRapidSpanningTreeProtocol(RSTP),MultipleSpanningTreeProtocol(MSTP)MultipleRegistrationProtocol(MRP)ShortestPathBridging(SPB)SoftwareDefinedNetworking(SDN)aspectsEnhancementstobridgingof802.11Operation,Administration,andMaintenance(OAM):ConnectivityFaultManagement(CFM)ProtectionswitchingManagementQualityofService(QoS)Enhancedtransmissionselection(ETS)Priority-basedflowcontrol(PFC)CongestionNotification(CN)StreamReservationProtocol(SRP)CreditbasedshaperPreemptionandtimescheduledqueuingPolicingOther802.1standardsnotcoveredbythistutorialLinkAggregationLinkLayerDiscoveryProtocol(LLDP)TimesynchronizationAudiovideobridgingsystemsBridgeportextensionSecuritySummaryReferencesAbbreviations,IEEE802.1Q,4,IEEE802.1Overview,March10,2013,IEEE802.1Q,5,IEEE802.1Q,6,IEEE802ishere:astandardscommitteeformedbytheComputerSociety,akaNesCom,akaRevCom,25IEEESocietiesPEdeviceBEB;CEdeviceC-MACbridge,BEB,BEB,BCB,NetworkVirtualizationIsBasedontheDataPlane,Dataplaneevolutionupto802.1Q-2011itisnotcomplicatedmaythinkoftagstackingProviderBridges(PB,Q-in-Q)ScalabilityOverlayingvirtualnetworks4KVLANproblemsolvedProviderBackboneBridges(PBB,MAC-in-MAC)Scalability24-bitI-SIDasasinglevirtualnetworkIDForgetaboutthe4KVLANproblemSeparationMACaddressspaceseparation(C-MACvs.B-MAC)Servicelayerisseparatedfromtransportlayer(I-SIDvs.B-VID)OverallUniformforwardingkept:basedonDestinationMAC(DA)andVIDL2dataplaneprovidespowerfulvirtualizationTheremaybeseverallevelsoftaggingorencapsulation,IEEE802.1Q,19,VirtualNetworksandOverlays,Virtualnetworknamesdonotboundtheirapplication!Alotofflexibilityisprovided,twoexamplesshownhereUsingallL2virtualnetworkoverlaysCanbeusedindatacenterandcampusnetworkstoo,notonlyinproviderenvironmentIPisanativeoverlayonEthernetIPpayloadcanbee.g.rightafterI-tagHostcanbeaVirtualMachinePBBcanbethecoreofadatacenter,IEEE802.1Q,20,20,ItIsAllAboutMappingofVirtualNetworkstoEachOtheratEdges,AnExternalEntityneedstoperformthemappingontheedgesAlltherestcanbedoneautomaticallybythedistributedcontrolplane,unlesstheExternalEntitymaintainsfullcontrol,seenextsectionIntelligenceisattheedges,CoreBridgesarerelativelydumb,IEEE802.1Q,21,S-VID:ServiceVLANIDI-SID:BackboneServiceInstanceIdentifierB-VID:BackboneVLANIDBEB:BackboneEdgeBridgeCB:CoreBridge,S-VIDI-SIDB-VIDmany-to-onemappings,EdgeVirtualBridging802.1Qbg,IEEE802.1Q,22,EdgeVirtualBridge-abridgeincorporatedintoanendnode(ofteninthenetworkinterfacehardware,hypervisororboth).VirtualEdgeBridge(VEB),orRelaystrafficbetweenVMslikeanexternalBridgeNotrequiredtosupportlearningsinceVMaddressesmaybeconfiguredNotrequiredtosupportanyspanningtreeprotocolasitisalwaysatthebridgednetworkedgeVirtualEdgePortAggregator(VEPA)SendsalltrafficfromVMstotheadjacentbridgeReflectiverelayinexternalBridgereturnsanyframesdestinedtolocalVMsMakesVMtoVMtrafficvisibletoadjacentbridgePoliciesdonothavetobedistributedtotheVEPA,VEB,VEPA,S-Channelsalso802.1Qbg,IEEE802.1Q,23,S-ChannelsarevirtuallinksbetweentheendsystemandtheadjacentBridgeTrafficcarriesanSVLAN-Tag(fromProviderBridging)toidentifyitwithanS-ChannelEachS-ChannelcanhaveasingleVM,aVEBorVEPAattachedNormally,evenwithasingleVMtherewillbea2-portVEBtohandleVLANTaginsertion,removalandtagging,S-Channels,ControlPlane,March10,2013,IEEE802.1Q,24,TopologyLayers(Contexts),IEEE802.1Q,25,PhysicalNetworkTopology,ActiveTopology,StationLocation(MACaddresstopology),VLANTopology,Subset(realornon-real),seeFigure7-1“VLANBridgingoverview”of802.1Qformoredetails,TheDistributedProtocolsforControloftheActiveTopology,IEEE802.1Q,26,RSTP:asinglespanningtreesharedbyalltrafficMSTP:differentVLANsmaysharedifferentspanningtreesSPB:eachnodehasitsownShortestPathTree(SPT)Wearenotlimitedtosharedspanningtreesanymore,RSTP:asinglespanningtreesharedbyalltrafficMSTP:differentVLANsmaysharedifferentspanningtrees,RSTPRapidSpanningTreeProtocol,MSTPMultipleSpanningTreeProtocol,SPBShortestPathBridging,Note:theSpanningTreeProtocol(STP)ishistorical,ithasbeenreplacedbyRSTP,MultipleRegistrationProtocol(MRP),Floodingprotocol(notunlikeIS-ISorOSPF)thatregisters,oneverybridgeport,onesneighborsabilitytotransmitand/orneedtoreceivevariouskindsofdata:MultipleVLANRegistrationProtocol(MVRP):FramesfloodedtoparticularVLANs,e.g.broadcastsorunknownunicasts.MultipleMACRegistrationProtocol(MMRP):MulticastMACaddressesorVLAN,MACpairs.NotnecessarilyIPmulticast.MultipleStreamReservationProtocol(MSRPorSRP):TalkerswantingtosendorListenerswantingtoreceivedataflowswithbandwidth,latency,andcongestionlossrequirements.InsomecasesMRPisbeingsupplantedbyIS-IS.,IEEE802.1Q,27,ControlPlaneOverview,IEEE802.1Q,28,Frameout,Framein,ControlPlane,ExternalAgent,MACBridge,HigherLayerEntities,AVLANisassignedtoacontrolmodeMultiplecontrolmodesmayco-existinthesamenetworkHybridcontrolbydistributedprotocolsandanExternalAgent,e.g.andSDNcontrollerforTEpathsExternalcontrolcanbeanon-802.1protocol:PCE,GMPLSSummaryofcontroloptions,softwaredefinedVLANs,shortestpathVLANs,ExternalAgent,ShortestPathBridging,VLANspace:,Control:,spanningtreeVLANs,MultipleSpanningTreeProtocol,SoftwareDefinedNetworkingAspects,SoftwareDefinedNetworking(SDN)principlesaresupportedby802.1QSeparationofthecontrolplanefromthedataplaneThebridgearchitectureseparatesthecontrolplanefromthedataplane(seepage13)TheExternalAgentisgeographicallyseparatedSeparatetopologiesperVLANAnygivenVLANcanbeassignedtoMSTP,SPB,ExternalAgent,oranyotherstandard-oruser-definedcontrolmethodologyCentralizedcontrollerhavingaviewofthenetworkTheExternalAgentcanbeacentralizedSDNControllerThebridgesmayruntheLinkLayerDiscoveryProtocol(LLDP)802.1ABforretrievalbycontrollerThebridgescanrunIS-IStodistributetopology,whetheranyVLANsareassignedtocontrolbySPBornotProgrammabilityofthenetworkWelldefinedobjectsandfunctionalityforprogrammingthebridges,IEEE802.1Q,29,ShortestPathBridging(SPB),SPBappliesalinkstatecontrolprotocoltoMACBridgingBasedontheISOIntermediateSystemtoIntermediateSystem(IS-IS)intra-domainroutinginformationexchangeprotocolISIS-SPBLeveragestheautomationfeaturesoflinkstate,e.g.auto-discoveryPreservestheMACServicemodel,e.g.deliveryin-orderISIS-SPBoperationLinkstatedatabaseIdenticalreplicaateachbridgeTopologyinformationPropertiesofthebridgesServiceinformationComputationinsteadofsignalingorregistrationprotocolsLeverageMooreslawandtechnologytrendsISIS-SPBspecificationsIEEE802.1aqspecifiesoperationandbackwardscompatibilityprovisionsISISextensionsforSPB(newTLVs)alsodocumentedinIETFRFC6329,IEEE802.1Q,30,SPBOperationModes,IEEE802.1Q,31,AbridgeonlyusesitsownSPTforframeforwardingDestinationMAC+VIDbasedforwardingallowstwooptionstorealizetheSPTs,ISIS-SPB,SPTBridge,SPTASPTC,SPBhastwooperationmodesTheimplementationofthesameprinciplestoforwardingisdifferent,SPBM:SPBMACBackboneMACidentifiedSPTsDesignedtoleveragethescalabilityprovidedbyPBB/“MAC-in-MAC”/NoB-MACflooding/learningManagedenvironments,SPBV:SPBVIDVIDidentifiedSPTsApplicabletoalltypesofVLANsFloodingandlearningPlug&play,LoadSpreading,IEEE802.1Q,32,UsingtheshortestpathautomaticallyspreadstrafficloadtosomeextentFurtherload-spreadingbyexploitingequalcostpathstocreatemultipleSPTSetsUpto16standardtie-breakingvariationstoproducediverseSPTsProvisionedloadspreadingAVLANisassignedtoanSPTSet,AnSPTSet,SPToptionsforBridgeA,AUseCase:ADataCenterwithSPBandSDNControl,SPBandSDNfittogetherandcomplementeachotherVirtualNetwork(VN)1issupportedbySPBMSDNControllerinstantiatestheconnectivityservicetobeprovidedforVN1attheEdgeBridges(EB)SPBMestablishestheconnectivityservicethoroughtheDataCenterNetwork(DCN)VN2issupportedbySDNSDNControllerestablishestheconnectivityservicetobeprovidedforVN2thoroughtheentireDCN,IEEE802.1Q,33,CreateI-SID3,SDNController(ExternalAgent),DCN,SPBFeatures,SinglelinkstatecontrolforlargenetworksHighdegreeofautomationScalability(scalesasIS-IS)Deterministicmulti-pathroutingforunicastandmulticastAddresslearningconfinedtothenetworkedgeFastconvergence(withintherangeof100msec)All802.1standardssupported,e.g.ConnectivityFaultManagement(802.1agCFM)EdgeVirtualBridging(802.1QbgEVB)MetroEthernetForum(MEF)servicesnativelyprovidedE-LINE,E-TREE,E-LAN,IEEE802.1Q,34,OngoingSPBRelatedActivities,DeploymentsMultiplevendorsshippingproductThreeinteropssofar:Alcatel-Lucent,Avaya,Huawei,Solana,SpirentEqualCostMultiplePaths(ECMP)802.1QbpPerhoploadbalancingforunicastSharedtreesformulticastStandardizedFlowHashOAMenablerNewtagtocarryFlowHashandTTLPathControlandReservation(PCR)802.1QcaBeyondshortestpathExplicitpathcontrolLeveraginglinkstateforBandwidthandstreamreservationRedundancy(protectionorrestoration)fordataflowsDistributionofcontrolparametersfortimesynchronizationandscheduling,IEEE802.1Q,35,EdgeVirtualBridgingControl802.1Qbg,IEEE802.1Q,36,EdgeVirtualBridgediscoveryandS-channelconfigurationLinkLayerDiscoveryProtocol(LLDP)802.1ABVirtualMachine(VM)migrationVirtualStationInterfaces(VSI):thenetworkinterfaceofaVMVSIDiscoveryandConfigurationProtocol(VDP)isusedtonotifyanadjacentbridgeofVSIs,EnhancementstoBridgingof802.11802.1Qbz,802.11ak,An802.11mediumisamediumjustlikeawiredmedium.Eachwirelesspoint-to-pointconnectioncanbemadevisibletoIS-ISasapoint-to-pointlink.Broadcaststomultiplestationsarehandledasanoptimizationofmulticasts/broadcastsofthesameframetoindividualpoint-to-pointlinks.Heuristicsandcostscausebridgestoavoidwirelesslinksexceptwhererequiredforconnectivity,andtopreventnetworkflapping.AnAccessPointisnotattachedtoabridge,itisabridge.Anon-APstationcanbeabridge,aswell.IEEE802.11smeshbecomesirrelevant.,IEEE802.1Q,37,Operation,Administration,andMaintenance(OAM),March10,2013,IEEE802.1Q,38,ConnectivityFaultManagement(CFM),CFM/OAMwascreatedinparallelwithITU-TY.1731.Itsvalueliesinitsarchitecture,whichsupports:Protocolinteractionsamongseparateadministrationswithaminimumofcommonconfiguration.Multiplelevelsofoperation,withtheabilitybothtopropagateerrorstohigherlevels,anddrilldowntolowerlevelswhenperformingfaultisolation.Completelydifferenttechnologiescanbesupportedatdifferentlevels,e.g.EthernetoverpseudowiresoverroutingoverframerelayoverEthernetoveroptical.Informationhiding,tomakelowerlevelstopology,equipment,orcontrolprotocolsinvisibletohigherlayers.,IEEE802.1Q,39,CFMSupportsDrill-down,IEEE802.1Q,40,CustomerMAC,CustomerMAC,BackboneMAC,Endpoints,Intermediatepoints,Apairofendpointsatagivenlevelseeonlytheintermediatepointsatthatlevel,ContinuityCheckMessage(CCM),CFM/OAMisdesignedfromthestartasatoolformultipointservicesnotjustpoint-to-point.Eachendpoint:TransmitsregularmulticastCCMsonitsownlevel.HasalistofotherendpointsonitslevelfromwhichitexpectstoreceiveCCMs.Setsa”RemoteDefectIndication”(RDI)bitifitsmissinganyCCMs,sothateveryendpointiseitherinthe”everyoneishappy”stateorthe”someoneisunhappy”state.TheglobalcircuitidentifierineveryCCMdetectsmerged(cross-connected)services.Point-to-pointcontinuitycheckscannotdetectmergedservices.Multicastmessagescandetectthem.,IEEE802.1Q,41,OtherCFM/OAMMessages,Endpoints/intermediatepointstiedtoports,notboxesLoopbackMessageandReply(LBM,LBR)Transmittedbyendpoint,reflectedbyintermediatepointorendpointCannotbeseenbyhigherorlowerlevels,confinedbyendpointstoalevelFordebugging,notformonitoringLinktraceMessageandReply(LTM,LTR)Withinalevel,findsintermediatepoints(ifany)onthewaytotheendpointITU-TY.1731definesotherTLVsandmessagetypesForerrorreporting,framelossmeasurement,latencymeasurement,andothermaintenanceactions,IEEE802.1Q,42,ProtectionSwitching,March10,2013,IEEE802.1Q,43,TEServiceInstanceProtectionSwitching,ExternallycontrolledBridgessupportend-to-endlinearprotectionforpoint-to-pointTrafficEngineeredServiceInstances(TESI),whereadedicatedprotectionpoint-to-pointTESIisestablishedforoneparticularworkingpoint-to-pointTESI,andthetrafficisautomaticallyswitchedfromtheworkingTESItotheprotectionTESIwhenafailureoccursontheworkingentity.TheprotectionswitchingmaybetriggeredbymanualoperationorbyCFMinformationarisingfrom,periodicmonitoringoftheworkingandprotectionpaths,orfromphysicallayermonitoring,suchaslossofsignalorotherdefectsdetectedthroughCFM.ThePBB-TEprotectionswitchingmechanismaimstoofferthecapabilitytoswitchcompletely(bothends)inlessthan50ms.SwitchingisachievedbychangingtheBackboneServiceInstancetableB-VIDentriesontheCustomerBackbonePortsassociatedwiththeTESIMaintenanceEndPoints(MEP).,IEEE802.1Q,44,Workingentity,Protectionentity,WestB-Component,EastB-Component,CCM,CCM,CCM,CCM,RDI,CCM,1:1protection,PNP,PNP,PNP,PNP,CBP,CBP,InfrastructureSegmentProtection8021.Qbf,ExternallycontrolledProviderBridgescansupportlocalizedprotectionofselectedtrafficengineeredservicestraversingacommonsequenceofProviderBridges,whichiscalledInfrastructureSegment.The1:1InfrastructureProtectionSwitching(IPS)isbasedontheTESIprotectionswitchingstatemachinesInaddition,M:1IPSprovidedIPSmaybetriggeredautomaticallybyachangeintheoperationalstateofanInfrastructureSegmentormanuallybyadministrativecommand.,IEEE802.1Q,45,Management,March10,2013,IEEE802.1Q,46,802.1QManagement,Clause12ManagedObjects(InformationModel)Structuredtextdescription,evolvingtostructuredtabularsummaryClause17SMIv2MIBs(DataModel)IETFstylepreamble(structure,security,relationships)10+MIBmodulespertechnologyTraps(Notifications)onlyspecifiedforCFM&PBB-TELimitedcountersBasedonoriginalIETFBRIDGEMIBworkRFC4663,“TransferringMIBWorkfromIETFBridgeMIBWGtoIEEE802.1WG”UseofifMIB,IEEE802.1Q,47,QualityofService,March10,2013,IEEE802.1Q,48,EnhancedTransmissionSelection(ETS)802.1Qaz,ProvidesforallocationoflinkbandwidthtotrafficclassesProprietaryweightedroundrobinfeatureswerealreadycommonETSprovidesauniformwaytomanagethedistribution.Coexistswithstrictpriorityandcredit-basedshapertrafficclassesStrictpriorityandcredit-basedshapertrafficgoesfirstETSdistributesremainingbandwidthDataCenterBridgingeXchangeProtocol(DCBX-alsoin802.1Qaz)usesLLDPtoshareETSandPFCconfigurationwithlinkpartnerAnendsystemmayusethatinformationtoadaptconfigurationtomatchthenetwork,IEEE802.1Q,49,Priority-basedFlowControl(PFC)802.1Qbb,Preventscongestiondropforprotocolsdesignedforflowcontrollednetworks(e.g.FiberChanneloverEthernet)PrioritiesareindividuallyconfiguredwithPFCTrafficinotherprioritiesnotaffectedOperatesacrossasinglehopPFCPauseFrameissenttopausetransmissionforatimedurationwhenreceivebufferreacheshighwatermark.Sendingwithzerotimevaluereleasesthepause.,IEEE802.1Q,50,CongestionNotification(CN),IEEE802.1Q,51,CNisappliedtotrafficinaCNpriorityWorksinaCNcloudwherealldevicessupportCNCanbeusedinconjunctionwithPFCPFCprovidesfastreactionCNslowssourcesonalongertimescale(10msforbandwidthdelayproductof5Mbit),CNmessagesentfromcongestionpointtosourceMACaddressofsampledframeQuantizedfeedback1to31indicatesseverityofcongestionUpto64bytesofthebeginningofthesampledframeincludedinCNmessage,StreamReservation,TheStreamReservationProtocol(SRP):AdvertisesstreamsinthewholenetworkRegistersthepathofstreamsCalculatesthe“worstcaselatency”SpecifiestheforwardingrulesforAVBstreamsEstablishesanAVBdomainReservesthebandwidthforAVBstreamsAnMRPApplicationEspeciallythebandwidthreservationisimportantinorderto:Protectthebestefforttraffic,asonly75%ofthebandwidthcanbereservedforSRclasstrafficProtecttheSRclasstrafficasitisnotpossibletousemorebandwidthforSRclasstrafficthan75%(thisisanimportantfactorinordertoguaranteeacertainlatency),IEEE802.1Q,52,StreamReservationExample,IEEE802.1Q,53,TalkerAdvertise,streamIDaccumulatedlatency=talkerlatencyframelengthinterval,streamIDaccumulatedlatency+=bridgelatencyframelengthinterval,streamIDaccumulatedlatency+=bridgelatencyframelengthinterval,S,S,S,S,S,S,ListenerReady,R,R,R,R,R,ListenerReady,R,S,S,S,S,S,R,R,TrafficShaping,Asaudio/videostreamsrequireahighbandwidthutilization,itwasnecessarytosetthemaximumavailablebandwidthforthisnewtrafficclassquitehigh(75%)TheCreditBasedShaper(CBS)spacesouttheframesasmuchaspossibleinordertoreduceburstingandbunching,thusProtectsthebestefforttrafficasthemaximuminterference(AVBstreamburst)forthehighestnon-AVBpriorityislimitedandknownProtectstheAVBstreams,asitlimitsthebacktobackAVBstreamburstswhichcaninterfereinabridgeTheCreditBasedShaperincombinationwiththeStreamReservationProtocolisintendedtoprovidedelaysunder250usperbridge.,IEEE802.1Q,54,CreditBasedShaperExample,IEEE802.1Q,55,PreemptionandTimeScheduledQueuing,Thecreditbasedshaperworkswellforaudio/videoapplications,butisnotsuitableforcontrolapplicationswhereworstcasedelaysmustbereducedtoaminimum.Time-aware(scheduled)queuingcombinedwithpreemptionreducesdelaystonearthebesttheoreticallevels,withtheminimumimpactonnon-scheduledtraffic.SRPoramanagementagentisrequiredtoprovideanadmissioncontrolschemetolimitlow-latencytraffictotheamountthatcanbesupportedbythelinksinthepathbetweenatalkerandcorrespondinglistener(s),IEEE802.1Q,56,Policing,Everyframecanbemarked“green”or“yellow”usingtheDropEligiblebitavailableforS-tagsandB-tags,oraprioritycodepointinC-tags.Policingisdoneperinputport,butonlyafteritisdeterminedthataframecanbedeliveredtosomeport.Framesthataredroppedbytheforwardingmechanismarenotpoliced.Policingistwo-colorin(greenoryellow)andthree-colorout(green,yellow,orred).Redaredropped.Yellowframeshaveahigherprobabilityofbeingdiscardedthangreenframes.PolicingalgorithmisfromMetroEtherForumspec10.2.,IEEE802.1Q,57,Other802.1StandardsnotCoveredbyThisTutorial,March10,2013,IEEE802.1Q,58,LinkAggregation802.1AX-REV,RevisioninprogressIncludesDistributedResilientNetworkInterconnect(DRNI)N