千兆以太网组网.ppt

千兆以太网组网. 1976XeroxPaloAltoResearchCenter1980年,DEC、Intel和Xerox提出以太网协议标准。以太网的设计目标(goals):简单(Simplicity)价格低(Lowcost)patibility)寻址灵活(Addressingflexibility)公平性(Fairness)先进性(Progress)高速(Highspeed)低时延(Lowdelay)稳定性(Stability)可维护性(Maintainability)层次结构(Layerarchitecture)以太网的(Non-goals)全双工(Full-duplex)差错控制(ErrorControl)安全性(Security)速率灵活性(SpeedFlexibility)优先级(Priority)不设防(HostileUser)以太网的发展进程()10BASE510BASE210BROAD3610Mbps,broadband,3600mCATVcable10BASE-T 10Mbps,baseband,overtwotwisted-paircable100BASE-T4100BASE-FX1000BASE-CX1000BASE-LX1000Mbps,longwavelengthoveropticalfiber1000BASE-SX1000Mbps,shortwavelengthoveropticalfiberLLC--ontrol(optional)MAC--10Mbps10Mbps100--lientSublayer-LLC,ontrol(optional)MAC---lientSublayer-LLC,ontrol(optional)MAC-essControlReconciliationGMIIPCSPMASX-PMDSX-MDI1000Base-X PHYMdiumIndependentInterfaceDataLinkMediumDependentInterface协调一致LX-PMDLX-MDICX-PMDCX--&y-1997全双工(交换机端口-网站)--1998VLANtagging介质访问控制(MAC)-1998“InformationTechnology-municationsandinformationexchangebetweensystems-work-Specificrequirements-Part3:esswithCollisionDetection(CSMA/CD)accessmethodandphysicallayerspecifications” ISO/IEC8802-3:-TUTP#-:LinkaggregationPreSFDDASAL/TDataPADFCSExt基本MAC帧格式和传输顺序传输顺序:自左至右,比特流帧开始界符1010**********-15004BytesO1O0MostSignificantOctetLeastSignificantOctetb0b7LSBMSBMSBLSB千兆以太网slottime大于分组传输所需时间,半双工,则在FCS后附加填充比特。