DOCSIS协议分析(中文).ppt

DOCSIS协议分析,议程,介绍DOCSIS；DOCSISPHY；DOCSISMACDOCSISCM与CMTS的交互过程；介绍DOCSIS1.1；DOCSIS1.1关键概念；DOCSISQoS特性集；新MAC管理消息；分段数据包（Fragmentation）；DOCSIS1.1安全；DOCSIS1.1上行调度算法；Concatenation；数据有效负载帧头压缩；DOCSIS2.0ProtocolAnalysis。,DOCSISProtocol演变,1997,DOCSIS1.0,1999,DOCSIS1.1,DOCSIS2.0,2001,1995,MCNS,DOCSIS标准,x4,Splitters2or3Way,DualWindowSMFiber1310/1550nm,DualWindowFOTransceivers,Multitaps8Port,Amplifiers1GHz2-Way,CableModem,CustomerPremisesEquipment,CMTS,DOCSISNetworkServersProvisioningDHCPTFTPToD,TOD,TFTP,DHCP,PROV,交换机/路由器,1GHzCoaxialCable,Upstream,Downstream,OSSI(OperationsSupportSystemInterface),CMTS-NSI(CMTSNetworkSideInterfaceSpecifications),RFI(RadioFrequencyInterfaceSpecifications),BPI-/BPI+(SecurityInterface),CMCI(CableModemCustomerSideInterfaceSpecifications),DOCSIS1.0功能,开放协议性非私有的。支持CM即插即用被设计为尽力可达早期版本标准不指定CM最小速率；由用户在1.0CMs和CMTSs间设定最小速率；支持尽力可达和CIR（保证最低的传输速率）的网络服务；CIR(CommittedInformationrate):除了突发，正常时提供CM的最小速率。不支持CBR（承诺速率）服务。灵活性:DOCSIS1.0增加MAC和PHY参数，灵活控制CM，以确保网络的稳健。安全与管理BPI(BaselinePrivacy)和BPI管理CM。兼容SNMP。远程软件更新。,CMTS架构HFC的参考模型,Tx,Rx,CATV分配网,Video1,Video2,Data,下行混频器,上行分支器,Data,调制,解调,逻辑桥接、路由,CMTS,前端,IP骨干网,交换机路由器光传输,CM(透明桥),CPE,DOCSIS与CATV频谱,下行频率88-860MHz,上行5-42/65MHz,8,802.3Ethernet,ATMMACLAYER,DOCSIS协议簇,802.3Ethernet,ATMMACLAYER,FiberOptic,Coax,UTPCopperPHYSICALLAYER,CableMACSUBLAYER,LLCSecuritySUBLAYER,DownstreamTransmissionConvergenceSUBLAYER,CablePMDSUBLAYER,UpstreamCablePMD,InternetProtocolIPNETWORKLAYER,FTPDHCPTFTPSMTPSNMPTelnetportsAPPLICATIONSLAYER,InternetProtocolIPNETWORKLAYER,FTPDHCPTFTPSMTPSNMPTelnetportsAPPLICATIONSLAYER,IPRoutingRIP,OSPF,MACTransparentBridging,CableMACSUBLAYER,LLCSecuritySUBLAYER,DownstreamTransmissionConvergenceSUBLAYER,CablePMDSUBLAYER,UpstreamCablePMD,InternetProtocolIPNETWORKLAYER,FTPDHCPTFTPSMTPSNMPTelnetportsAPPLICATIONSLAYER,FiberOptic,Coax,UTPCopperPHYSICALLAYER,InternetProtocolIPNETWORKLAYER,FTPDHCPTFTPSMTPSNMPTelnetportsAPPLICATIONSLAYER,x4,MACTransparentBridging,CMTS,CM,HFCNetwork,HybridFiberOpticCoaxialHFCNetworkPHYSICALLAYER,9,DOCSIS与OSI,北美DOCSIS1.x下行PhysicalMediaDependentSublayer,下行：91-857MHz，+/-30khz6MHzchannelwidths连续调制两种调制类型：64QAM、256QAM两种符号速率5.0MSymbolspersec5.3MSymbolspersec一端发送多端接收CM侦听下行信号,6bitspersymbol,8bitspersymbol,DataRate,Bandwidth,欧标DOCSIS是基于DOCSIS1.0/1.1规范制定的欧标物理子层和MAC；DVB(DigitalVideoBroadcasting)在下行8MHz通道QAM调制；64或256QAM可达到6.952Msps符号速率；5-65MHz上行频率范围,欧洲DOCSIS1.x下行PhysicalMediaDependentSublayer,北美DOCSIS1.x上行PhysicalMediaDependentSublayer,上行5-30/42MHz在UCD中定义符号速率时分多址（TDMA）：把时间分割成周期性的帧(Frame)每一个帧再分割成若干个时隙向CMTS发送信号,一点对多点的接收方式CM数据在上行调制发送,MPEGHeaderpointer_fieldDOCSISPayload(4bytes)(1byte)(183or184bytes),北美DOCSIS1.xPHY,下行传输汇聚子层（PHY)MPEGII帧长为：183/184bytesMPEG数据帧头PID为：0 x1FFE,MPEGHeaderContinuationofMACFrame#1(4bytes)(184bytes),MPEGHeaderpointer_fieldTailofMAC#1(4bytes)(1byte)MbytesMbytes,StartofMAC#2,一个MPEG帧头可装载多个DOCSISMAC帧,MPEGHeaderpointerfieldStartofMACframe#1(4bytes)(1byte)(upto183bytes),DOCSISMAC层,CMTS对CM作带宽分配控制；在上行，时隙和时隔又由微时隙(minislot)组成；带宽分配的最小单位：微时隙支持CoS（ClassofService）；安全：BPI；服务标识SIDs14bits0 x0000未初始化的CMSID；0 x3FFF信令，对所有CMs；组播SIDs用于请求或数据包；组播MAC01:E0:2F:00:00:01。,DOCSISMAC帧类型,FC_Type,FC_PARM,EHDRON,EHDRLENConcFramecountRequests,LengthorSID,00:Ethernet11:MacHeader,00000Ethernet00000Timing00001MacMan00010Req11100Concat,ExtendedMACheaders,0to240bytes,DOCSIStiming参数,MapLeadtime：前置时间；Thesyncmessage：同步消息；Minislotsize：微时隙大小；分配开始时间和时间偏移量；CM到CMTS的上行时延。,DOCSISMAC管理消息,SYNCTimingSynchronization：同步消息；UCD：上行通道描述；MAPUpstreamBandwidthAllocation：上行带宽分配；RNG-REQ：Ranging请求；RNG-RSP：Ranging响应；REG-REQ：注册请求；REG-RSP：注册响应；UCC-REQ：上行通道改变请求；UCC-RSP：上行通道改变响应；BPKM-REQ：密钥管理请求DOCSIS8BPKM-RSP：密钥管理响应DOCSIS8,CMandCMTS交互过程,CM扫描并与下行同步；CMTS获得上行参数；CMTSRanging、自动调节物理参数与CM适配；建立IP连接；建立ToD(timeofday)；向CM传输操作参数；注册；BPI(BaselinePrivacyinitialization)：可选。,获取下行通道和时间,CM获取下行信息保存最后锁定的BOOT频率到NVRAM；扫描下行每6/8MHz间隔65/88-860MHz。识别DOCSIS包PID0 x1FFE。CM获得与CMTS同步CMTS广播下行给所有CM；CMs读取CMTS的Timing并调节本地时钟（时钟最小单位0.98微妙)。(6.25usec/64=.09765625usec=1/4thesymboldurationofthehighestrate=10.24MHz),CMTS,CM,CM:Syncinsertion=200msecMaxLostSync=600msec,UCDs,CMTS广播UCD给所有CM；UCD维护每个CM与CMTS间的通信InitialMaintenance：初始化Request：请求StationMaintenance：站点维护Data-Short/Long：数据包大小UCD内容：中心频率通道带宽调制方式微时隙大小FEC,CMlearnsallUCDsavailableandbuildsatable,UCDinsertion=2secmaxTimeout-T1=5*MAXUCDinterval,CMTS,CM,DOCSIS微时隙,Minislots表示CMTS每处理固定大小字节的数据包需要的byte-time；6.25usec为基本单位。增加微时隙时间可选择：2、4、8、16、32、64和128乘以6.25作为“minislot”。如26.25微秒；微时隙的时间：12.5、25、50、100、200、400and800微秒。,ExampleValue,TimeTicksBytesperminislotSymbolsperbyteSymbolspersecondMinislotspersecondusecsperminislotTicksperminislot,Parameter,6.25usecs16bytes42.560msys40,000254,UpstreamChannelDescriptor,CMTSMACHeaderFCType:3MACSpecificFCParm:1ManagementEhdr:0EhdroffMACParm:0 x00ReservedLen:0 x0146HCS:0 x0000,CMTSMACManagementDestination:01:E0:2F:00:00:01Source:00:50:57:00:28:96Len:308DSAP:0 x00SSAP:0 x00Control:0 x03Version:0 x01Type:0 x02UCDReserved:0 x00UpstreamChannelId:0 x02ConfigChangeCount:0 x01MiniSlotSize:0 x02DownstreamChannelId:0 x01,BroadcastMAC,UCDOverallChannelTLVs,UCDTLVs:TLVType/Length:1/1SymbolRateSymbolRate:16(x160ksym/sec)TLVType/Length:2/4FrequencyUpstreamCenterFreq.:23000000,UCDBurstAttributes,TLVType/Length:3/92PreamblePatternPreambledata:TLVType/Length:4/37BurstDescriptorIUC:1RequestAttrType/Length:0 x01/1ModulationTypeValue:1QPSKAttrType/Length:0 x02/1DifferentialEncodingValue:2OffAttrType/Length:0 x03/2PreambleLengthValue:64AttrType/Length:0 x04/2PreambleValueOffsetValue:56AttrType/Length:0 x05/1FECErrorCorrectionValue:0AttrType/Length:0 x06/1FECCodewordInfoBytesValue:16AttrType/Length:0 x07/2ScramblerSeedValue:338AttrType/Length:0 x08/1MaxBurstSizeValue:2AttrType/Length:0 x09/1GuardTimeSizeValue:8AttrType/Length:0 x0A/1LastCodewordLengthValue:1FixedAttrType/Length:0 x0B/1Scrambleron/offValue:1On,BandwidthAllocation-MAP,32bitelementsdescribingbandwidthintothefuture.broadcasttoallmodemsMaxnumberof4096minislots.,WHOSID14bits,maybeabroadcastorunicast.WHATIUCbursttype4bitsRequestInitialMaintenanceStationMaintenanceShortDataLongDataWHENTimingoffset14bits,UCDs,BandwidthAllocationMAP,CM,MAPInformationElements,RequestIntervalUsedbytheCMtosendrequeststotransmitdatatotheCMTSInitialMaintenanceUsedbynewcablemodemstojointhethenetworkStationMaintenanceUsedbycablemodemstoadjustthierHFCandtimingparametersShortDataUsedtosenddata-thelengthisdefinedinthemaximumtransmitburstparameterintheUCDorconfigfile.LongDataUsedtosendlongdata-maximumtransmitburstdefinedintheUCDorconfigfileNullIEUsetoindicatetheendoftheMAP,BandwidthAllocationMAP,CMTSMACManagementDestination:01:E0:2F:00:00:01Source:00:50:57:00:28:96Len:30DSAP:0 x00SSAP:0 x00Control:0 x03Version:0 x01Type:0 x03MAPReserved:0 x00UpstreamChannelId:0 x01UCDCount:0 x05NumberofElements:0 x02Reserved:0 x00AllocStartTime:0 x0198B778AckTime:0 x0198B596RangingBackoffStart:0 x02RangingBackoffEnd:0 x03DataBackoffStart:0 x05DataBackoffEnd:0 x0A,BroadcastMAC,MAPInformationElements,MAPInfoElements:SID:0 x0001IUC:0 x0006;LongDataGrantOffset:0 x0000SID:0 x3FFIUC:0 x0001;RequestOffset:0 x0009SID:0 x0000;NullIEIUC:0 x0007Offset:0 x009FFrameCheckSequence:0 x00000000,Ranging,StoreTemporarySIDandadjustparameters,AllocatetemporarySID,Transmitattempts16,RNGInterval2secondsmax,T3timeoutMin50msecMax200msec,CM,InitialRanging,ucd1ucd4,ucd1ucd4,ucd1ucd4,picksucd1,Scenario1CMTShearsonport4Redirectsmodemtouseucd4inrangingresponse,sendsrangingrequest,Scenario2CMTSneverhearsmodemModemwilltimeoutanduseucd4,sendsrangingresp,picksucd4,rerange,CM,RangingRequest,RangingResponse,RangeResponseTLVs:TLVType/Length:1/4TimingAdjustTXTimingoffset:1250TLVType/Length:2/1PowerLevelAdjustTXpoweroffset:24TLVType/Length:3/2OffsetFreq.AdjustTXFrequencyoffset:0TLVType/Length:5/1RangingStatusRangingStatus:1ContinueUnknownFrameCheckSequence:0 x00000000,Provisioning,UCDs,MAP,DynamicHostConfigurationProtocolDHCPRFC2131TrivialFileTransferProtocolTFTPRFC1123Time-of-dayRFC-868,CM,DynamicHostControlProtocol,DHCPDiscover,DHCPOffer,DHCPrequest,DHCPAck,DHCPRelayAgent,CM,DHCPDiscover,DHCP-DynamicHostConfigurationProtocolDHCPMagicCookie:0 x63825363MessageTypeDHCPOptionOptionCode:53MessageTypeOptionLength:1MessageType:1DiscoverClientIdentifierDHCPOptionOptionCode:61ClientIdentifierOptionLength:7HardwareType:1HardwareAddress:00:90:83:37:CA:9CParameterRequestListDHCPOptionOptionCode:55ParameterRequestListOptionLength:5RequestedOption:1SubnetMaskRequestedOption:2TimeOffsetRequestedOption:3RoutersRequestedOption:4TimeServersRequestedOption:7LogServersVendorClassIdentifierDHCPOptionOptionCode:60VendorClassIdentifierOptionLength:9OptionData:DOCSIS1.0646F63736973312E30DHCPOptionEndOptionCode:255End,DHCPOfferLayer3-BootP,BootP-BootstrapProtocolOperation:2BootReplyHardwareAddressType:1Ethernet(10Mb)HardwareAddressLength:6bytesHops:0TransactionID:183996391SecondsSinceBootStart:0Flags:0 x0000IPAddressKnownByClient:IPAddressNotKnownByClientClientIPAddrGivenBySrvr:ServerIPAddress:GatewayIPAddress:ClientHardwareAddress:00:90:83:37:CA:9CUnused:0 x00000000000000000000ServerHostName:.BootFileName:BASDefaultCMConf42415344656661756C74434D436F6E66ig1.0.cfg.6967312E302E63666700000000000000.,DHCPOfferApplicationLayer,DHCP-DynamicHostConfigurationProtocolDHCPMagicCookie:0 x63825363MessageTypeDHCPOptionOptionCode:53MessageTypeOptionLength:1MessageType:2OfferServerIdentifierDHCPOptionOptionCode:54ServerIdentifierOptionLength:4Address:IPAddressLeaseTimeDHCPOptionOptionCode:51IPAddressLeaseTimeOptionLength:4Value:36000SubnetMaskDHCPOptionOptionCode:1SubnetMaskOptionLength:4Address:RoutersDHCPOptionOptionCode:3RoutersOptionLength:4Address:TimeServersDHCPOptionOptionCode:4TimeServersOptionLength:4Address:LogServersDHCPOptionOptionCode:7LogServersOptionLength:4Address:,DHCPRequest,DHCP-DynamicHostConfigurationProtocolDHCPMagicCookie:0 x63825363MessageTypeDHCPOptionOptionCode:53MessageTypeOptionLength:1MessageType:3RequestRequestedIPAddressDHCPOptionOptionCode:50RequestedIPAddressOptionLength:4Address:ServerIdentifierDHCPOptionOptionCode:54ServerIdentifierOptionLength:4Address:ClientIdentifierDHCPOptionOptionCode:61ClientIdentifierOptionLength:7HardwareType:1HardwareAddress:00:90:83:37:CA:9CParameterRequestListDHCPOptionOptionCode:55ParameterRequestListOptionLength:5RequestedOption:1SubnetMaskRequestedOption:2TimeOffsetRequestedOption:3RoutersRequestedOption:4TimeServersRequestedOption:7LogServersVendorClassIdentifierDHCPOptionOptionCode:60VendorClassIdentifierOptionLength:9OptionData:DOCSIS1.0646F63736973312E30DHCPOptionEnd,DHCPACK,DHCP-DynamicHostConfigurationProtocolDHCPMagicCookie:0 x63825363MessageTypeDHCPOptionOptionCode:53MessageTypeOptionLength:1MessageType:5ACKServerIdentifierDHCPOptionOptionCode:54ServerIdentifierOptionLength:4Address:IPAddressLeaseTimeDHCPOptionOptionCode:51IPAddressLeaseTimeOptionLength:4Value:36000SubnetMaskDHCPOptionOptionCode:1SubnetMaskOptionLength:4Address:RoutersDHCPOptionOptionCode:3RoutersOptionLength:4Address:TimeServersDHCPOptionOptionCode:4TimeServersOptionLength:4Address:LogServersDHCPOptionOptionCode:7LogServersOptionLength:4Address:DHCPOptionEndOptionCode:255End,TimeofDay,UsedforLoggingpurposesMultipleServersfromDHCPofferNotmandatoryforregistrations(somemodemsrequire),UDP-UserDatagramProtocolSourcePort:1024DestinationPort:37TimeLength:8Checksum:0 xEFAFUDPDataArea:Nomoredata.Extrabytes(Padding):202020202020202020202020202020202020005590D3FrameCheckSequence:0 x00000000,Provisioning:TFTP,UDP-UserDatagramProtocolSourcePort:1025DestinationPort:69TFTPLength:42Checksum:0 x445DTFTP-TrivialFileTransferProtocolOpcode:1RRQ-ReadRequestFilename:BASDefaultCMConfig1.0.cfgMode:octetExtrabytes(Padding):6F2BC024FrameCheckSequence:0 x00000000,GiveninDHCPoffer,Registration,SendRegistrationResponseAuthenticationFailClassofServiceFailureSuccess,CalculateCMTSMICCheckTFTPtimestampTFTPmodemaddressVerifyCOS/QOSassignSFIDVerifyModemcapabilitiesAssignpermanentSID,ConfigFileReceivedCMMICValid,ProvServer,RelevantTimeoutsT9=15minutes,CM,ProvisioningServer,OperationalParameters:Provservsharedsecret:,HEX,ASCII,Format:,ConfigSetting1,ConfigSetting2,ConfigSettingn,docsisclass,CMTSParameter:SharedSecret:,docsisclass,2F21D666B8A13C39E3,docsisclass,MessageIntegrityCheckAppendixC5&C6,CM,RegistrationRequest,RegistrationRequestTLVsTLVType/Length:3/1NetworkAccessControlObjectObjectValue:0 x01TLVType/Length:4/31ClassofServiceEncodingsSubType/Sublength:1/1ClassIDClassID:1SubType/Sublength:3/4MaxUpstreamDataRateMaximumReturnRate:64000SubType/Sublength:2/4MaxDownstreamDataRateMaximumForwardRate:1000000SubType/Sublength:4/1UpstreamChannelPriorityReturnpathpriority:1SubType/Sublength:5/4GuaranteedMinimumUpstreamRateGuaranteedrate:64000SubType/Sublength:6/2MaximumUpstreamChannelBurstMaximumburstsize:0SubType/Sublength:7/1C-o-SPrivacyEnabled,RegistrationRequestcont.,CosEnable:0DisabledTLVType/Length:18/1Maximum#ofCPEsNumberofCPEs:1TLVType/Length:6/16CMMICIntegrityCheck:A93F64A4821301C2F8B640E0E0C3B57CTLVType/Length:7/16CMTSMICIntegrityCheck:2F21D666B8A13C39E3F4DC13CEDCC360TLVType/Length:5/3ModemCapabilitiesSubType:1ConcatenationSupportSubLength:1Concatenation:1OnTLVType/Length:12/4ModemIPAddressModemAddressTLVType/Length:8/3VendorIDEncodingVendorOUI:0 x00:0 x90:0 x83Extrabytes(Padding):1098D6EFFrameCheckSequence:0 x00000000,RegistrationResponse,RegistrationResponseTLVsTLVType/Length:1/7ServiceClassDataSubType/Sublength:1/1ClassIDClassID:1SubType/Sublength:2/2SIDSID:0 x000FTLVType/Length:5/3ModemCapabilitiesSubType:1ConcatenationSupportSubLength:1Concatenation:0OffFrameCheckSequence:0 x00000000,BaselinePrivacy,ProvidesbasicprivacytouserdataacrosstheRFnetworkDiscouragestheftofserviceEverymodemhasanRSApublic/privatekeypair.RSAkeypairisusedtosecurelyexchangeDESkeyswiththeCMTS.AlldatapacketsareDESencrypted.Doesnotprovidemodemauthentication.ConfiguredintheTFTPConfigurationfile.TwoStateMachinesAuthorizationStateServiceKeyState,RegistrationRequest,RegistrationResponse,DHCP,TFTP,TOD,RangingRequest,RangingResponse,AuthRequest,AuthReply,Keyrequest,Keyreply,CM,ModemTransmission,AtthispointtheCMisregisteredandprovisionedwiththeCMTSTheCMjoinsintothecontentionbasedGrant/RequestprocesstoacquireUpstreambandwidthasnecessaryallowinghostCPEstoforwardpacketsintotheHFCnetwork.,Request,(contention),Grant,Data,Requestopportunity(broadcast),CM,TransmitOpportunities,HowtheCMasksforbandwidthStandalonePiggybackTotalnumberofmini-slotsneededtotransmitPDU+POHOnerequestperSIDMustusegrantsgiven0lengthgrantsACKS,DOCSIS1.xMACLayerInteractions,T11,T7,T9,SecondMAP,T5,FirstMAP,T4,CalculateDelay,T2,ReadMAPforreqopp,T6,CalculateCollision,T1,CreateMAP,SendReq,T8,ReadMapfordatagrant,T10,CalculateDelay,SendData,CMTS,CM,TransmitopportunitiesandCollisionAvoidance,CMTSMACManagementDestination:01:E0:2F:00:00:01Source:00:50:57:00:28:96Len:30DSAP:0 x00SSAP:0 x00Control:0 x03Version:0 x01Type:0 x03MAPReserved:0 x00UpstreamChannelId:0 x01UCDCount:0 x05NumberofElements:0 x02Reserved:0 x00AllocStartTime:0 x0198B778AckTime:0 x0198B596RangingBackoffStart:0 x02RangingBackoffEnd:0 x03DataBackoffStart:0 x05DataBackoffEnd:0 x0AMAPInfoElements:SID:0 x3FFFIUC:0 x0001RequestOffset:0 x0000SID:0 x0000IUC:0 x0007NullIEOffset:0 x00A0FrameCheckSequence:0 x00000000,CM,StationMaintenance,AtsomepredeterminedintervalallregisteredCMswillberequiredtoperformPeriodicMaintenance.Thisisaunicastopportunitypermodemtoadjustitsloopdelay,power,equalizationandfrequency.Atleastevery30seconds,RangingRequest,RangingResponse,CM,UpstreamChannelChange,Usedfor:TrafficbalancingNoiseAvoidanceRedoInitialRangingDonotreregister,UCCRequest,UCCResponse,CM,UCCRequest,CMTSMACManagementDestination:00:90:83:36:D8:5ASource:00:50:57:00:30:36Len:8DSAP:0 x00SSAP:0 x00Control:0 x03Version:0 x01Type:0 x08UCC-REQReserved:0 x00UpstreamChannelId:0 x01Extrabytes(Padding):.01020101FrameCheckSequence:0 x00000000,UCCResponse,CMTSMACManagementDestination:00:50:57:00:30:36Source:00:90:83:36:D8:5ALen:7DSAP:0 x00SSAP:0 x00Control:0 x03Version:0 x01Type:0 x09UCC-RSPReserved:0 x00UpstreamChannelId:0 x01Extrabytes(Padding):281CE58EFrameCheckSequence:0 x00000000,DOCSIS1.1,SectionIIObjectives,DescribethenewfeaturesinDOCSIS1.1.DescribeDOCSIS1.0and1.1Interoperability.SummarizeDOCSIS1.1Concepts.RecognizeQOSParameterSets.ListnewMACManagementMessages.DiscussFragmentation.DiscussDOCSIS1.1Security.DefineDOCSIS1.1UpstreamSchedulingAlgorithms.DefineConcatenation.DefinePayloadHeaderSuppression.DescribePacketCableProject,WhyDOCSIS1.1?,Inv1.0,aCMtreatsallservicesthesame,theygoagainstasingleratelimit.WebBrowsingEmailFileTransferNeededtoofferbetterthanbest-effortservices.Real-timemultimediaservicesTieredServicesVoiceoverIPVoIPisthekeymotivator.(PacketCable)Inv1.1,individualservicescangetindividualbandwidthguarantees.ProvidesthemechanismstosupportQoSforboththeupstreamanddownstreamtrafficthroughtheCMandCMTS.,DOCSIS1.1Fetures,DOCSIS1.1buildsontopoftheDOCSIS1.0RFIspecification.ProvideskeyMACLayerenhancementstoDOCSIS1.0MultipleFlowspermodem.Classificationofpackets.DynamicAddition,Deletion&ChangeofServiceFlows.Twophasecommit/activationsupportfortelephony.Pre-definedSchedulingAlgorithmsforRealTimePollingapplications.FragmentationCableModemmandatorysupportforconcatenation(optionalin1.0).Payloadheadersuppressiontoreduceoverhead.VAD(VoiceActivityDetection)support.BPI+mandated.,DOCSIS1.1KeyConcepts,ServiceFlow,QoSParameters,Latency,Jitter,Bandwidth,SFID,IEEEIPEthernet,Downstream,Upstream,sid1sid1sid1sid1,Tootherflows,Tootherflows,Tootherflows