文档介绍：workConsultingEngineerAdvanceServices©2001,CiscoSystems,-RouterInternals&Operation-Introduction+RouterArchitectures+IOSPacketSwitching©2001,CiscoSystems,•Routershavetodealinthree“Planes”ofoperation:-The“Control”PlaneBuildingandmaintainingdatastructuressuchas“forwardingtables”FIB,routecachetable…The“Management”PlaneDealingwithconfigurationfiles,gatheringandprovidingstatistics,providingandrespondingtocontrolprotocolmessagesThe“Data”PlaneSwitchingofpackets,manipulationofpacket(headerandcontent),packetdeliveryscheduling(queuing)©2001,CiscoSystems,–ConsumableResourcesCPUMemoryBandwidthWhenanyalloralloftheresourcesareexhausted,inconsistentbehaviorwillbeobserved©2001,CiscoSystems,-RouterInternals&Operation-RouterArchitectures•SharedMemory+SharedMemory(DistributedProcessors)•CrossBars+IOSPacketSwitching©2001,CiscoSystems,(ewer)ForwardingTablesBuffersIOSImage/FilesPacketQueuesCPUMemoryPointersSystemBuffersMemoryHeadersProcessorQueuesData/Address/ControlBus’sPhysicalMediaInterfacesInterfaceInterfaceInterfaceInterfaceInterfaceInterfaceInterface(FixedorModular)InterfaceInterfaceInterfaceInterfaceInterfaceInterfaceInterface©2001,CiscoSystems,-RouterInternals&Operation-RouterArchitectures•SharedMemory+SharedMemory(DistributedProcessors)•CrossBars+IOSSoftware©2001,CiscoSystems,(DistributedProcessors/Memory)CPUCPUMemoryMemory(DRAM)(DRAM)CPU(C)ForwardingTablePacketMemoryInterfaceCardEachLinecardhasPacketI/OBuffer(D)FTCPUMemory,ForwardingTableI/OBufferMemoryandadiscreteI/(D)FTCPUACopyofthecentralI/OBufferPacketMemory(SRAM)Interfaceforwardingtableis(SRAM)I/OBufferpropagatedfromtheCardI/OBuffer(D)FTCPUCentralRouteProcessortotheLineCardsforLocalI/OBufferSharedPacketMemorySharedPacketMemoryPacketMemoryInterfaceswitchingofpacketsCard(D)FTCPU©2001,CiscoSystems,-RouterInternals&Operation-RouterArchitectures•SharedMem