SIS-协议分析(中文版)

DOCSIS－协议分析议程介绍DOCSIS；DOCSISPHY；DOCSISMACDOCSISCM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1997DOCSIS1.01999DOCSIS1.1DOCSIS2.020011995MCNSNewMACFeaturesBackwardcompatibility“QualityofService”IncreasedSecurityNewPhyLayerIncreasedBandwidthIncreasedRobustnessGlobalStandardforMAC-DataoverHFCDOCSIS标准x4Splitters2or3WayDualWindowSMFiber1310/1550nmDualWindowFOTransceiversMultitaps8PortAmplifiers1GHz2-WayCableModemCustomerPremisesEquipmentCMTSDOCSISNetworkServers•Provisioning•DHCP•TFTP•ToDTODTFTPDHCPPROV交换机/路由器1GHzCoaxialCableUpstreamDownstreamOSSI(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TxRxCATV分配网Video1Video2Data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)CPEDOCSIS与CATV频谱下行频率88-860MHz上行5-42/65MHz5MHz42MHz54MHz550MHzLocalVideoSatelliteVideoAddressableConvertersIPPVIPPVLocalVideo750/860MHzDigitalVideoDOCSISTelephonyDOCSISTelephony88MHz8802.3Ethernet,ATMMACLAYERDOCSIS协议簇802.3Ethernet,ATMMACLAYERFiberOptic,Coax,UTPCopperPHYSICALLAYERCableMACSUBLAYERLLCSecuritySUBLAYERDownstreamTransmissionConvergenceSUBLAYERCablePMDSUBLAYERUpstreamCablePMDInternetProtocol[IP]NETWORKLAYERFTPDHCPTFTPSMTPSNMPTelnet[ports]APPLICATIONSLAYERInternetProtocol[IP]NETWORKLAYERFTPDHCPTFTPSMTPSNMPTelnet[ports]APPLICATIONSLAYERIPRoutingRIP,OSPFMACTransparentBridgingCableMACSUBLAYERLLCSecuritySUBLAYERDownstreamTransmissionConvergenceSUBLAYERCablePMDSUBLAYERUpstreamCablePMDInternetProtocol[IP]NETWORKLAYERFTPDHCPTFTPSMTPSNMPTelnet[ports]APPLICATIONSLAYERFiberOptic,Coax,UTPCopperPHYSICALLAYERInternetProtocol[IP]NETWORKLAYERFTPDHCPTFTPSMTPSNMPTelnet[ports]APPLICATIONSLAYERx4MACTransparentBridgingCMTSCMHFCNetworkHybridFiberOpticCoaxial[HFC]NetworkPHYSICALLAYERCMTS9CMTS广域网CMTS-NSIHFCCMTVPCTelRFI上/下行RFI上/下行CMCICMTRI透明的IP传输系统SNMPTFTPDHCPUDPIP、IGMPLLC/DIXARP链路安全MAC传输汇聚（只对下行）PMD网络层以上数据链路层物理层DOCSIS与OSI北美－DOCSIS1.x下行[PhysicalMediaDependentSublayer]下行：91-857MHz，+/-30khz6MHzchannelwidths连续调制两种调制类型：64QAM、256QAM两种符号速率5.0MSymbolspersec5.3MSymbolspersec一端发送多端接收CM侦听下行信号6bitspersymbol8bitspersymbolDataRateBandwidthChannelWidth(MHz)64QAMSpeed(bits/sec)256QAMSpeed(bits/sec)6MHzNorthAmericanDOCSIS30Mbps[Less10%FEC]27Mbps43Mbps[Less10%FEC]39MbpsDataRateBandwidth6bitspersymbol8bitspersymbol58Mbps[Less10%FEC]52Mbps40Mbps[Less10%FEC]36Mbps8MHzEuropeanDOCSIS256QAMSpeed(bits/sec)64QAMSpeed(bits/sec)ChannelWidth(MHz)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2bitspersymbolSymbolRate(ksym/sec)16032064012802560ChannelWidth(KHz)20040080016003200QPSKSpeed(bits/sec)320,000bps640,000bps1,280,000bps2,560,000bps5,120,000bps16QAM(bits/sec)640,000bps1,280,000bps2,560,000bps5,120,000bps10,240,000bps4bitspersymbolKsym/sec=kbps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：183/184bytesMPEG数据帧头PID为：0x1FFEMPEGHeaderContinuationofMACFrame#1(4bytes)(184bytes)MPEGHeaderpointer_fieldTailofMAC#1(4bytes)(1byte)MbytesMbytesStartofMAC#2一个MPEG帧头可装载多个DOCSISMAC帧MPEGHeaderpointerfieldStartofMACframe#1(4bytes)(1byte)(upto183bytes)DOCSIS－MAC层CMTS对CM作带宽分配控制；在上行，时隙和时隔又由微时隙(mini—slot)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－SIDs14bits0x0000未初始化的CMSID；0x3FFF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。DOCSIS－MAC帧类型FC_TypeFC_PARMEHDRONEHDRLENConcFramecountRequestsLengthorSID00:Ethernet11:MacHeader00000Ethernet00000Timing00001MacMan00010Req11100ConcatFCMAC_PARMLENHCSEHDRPDUVariousDASALENCRCDATAEthernetFCMAC_PARMLENHCSDown-SYNCUpstream-RNG-REQTimingFCMAC_PARMLENHCSMacManagementMessageMacManagementFCMAC_PARMLENHCSRequestExtendedMACheadersFCMAC_PARMLENHCSEHDRPDUVarious0to240bytesEH_TYPEEH_LENEH_VALUE00Null/padding13Request:minislots/SID22ACK345UpstreamPrivacyUpstreamprivacywithfrag445DownstreamPrivacyDownstreamprivacywithfrag51DownstreamPHS612UpstreamPHSUpstreamPHSwithUGSH1.11.1DOCSIStiming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[DOCSIS8]BPKM-RSP：密钥管理响应[DOCSIS8]CMandCMTS交互过程1.CM扫描并与下行同步；2.CMTS获得上行参数；3.CM