GMPLSOverview

2zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseGMPLSOverviewIPTNGMShanghaiESW4DongPengfei3zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseHistoryVersionDescriptionDateAuthor0.1FirstVersion2008.10.08DongPengfei4zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseGeneralAgenda•数据通信网络概述•内部网关协议OSPF概述•传统MPLS及MPLS-TE概述•GMPLS基本架构•邻居发现•信令过程•Q&A5zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseIPPacketSwitch与MPLSLabelSwitchIP网络是一个HOP-BY-HOP进行转发决策的网络路由器（Router)根据IP头中的目的地址查找转发表进行转发决策找到出接口根据MPLSLABEL进行标签交换找到出接口6zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15Forinternaluse路由表(RIB)与转发表(FIB)静态配置或动态路由计算得出的由目的地址和下一跳组成的表项FIB表是RIB表的子集，经过优选后写入硬件进行转发决策7zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15Forinternaluse路由表的形成直连路由，混沌初开静态路由，上帝说要有光，于是便有了光动态路由，我们说着同样的语言；IGP与BGPIGP中距离矢量与链路状态，传直接的路由，还是传间接的链路状态8zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15Forinternaluse链路状态协议OSPF一个接口标识一条链路，一条链路连接一个网络接口地址标识网络32位掩码地址标识一个节点，此时路由器与主机在网络中的角色一样,通常配置在loopback接口上，这种接口是逻辑上的不会进行实际的转发9zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15Forinternaluse邻居(Neighbor)发现与DR选举使用OSPFHELLO报文进行邻居发现HELLO报文使用保留组播地址224.0.0.5发往本广播域的所有路由器DR选举的作用是在Multi-Access网络（Broadcast或NBMA）中避免形成N*(N-1)个邻居10zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15Forinternaluse邻接(Adjacent)关系的形成Anadjacencyisestablishedinfourgeneralphases:Neighbordiscovery.Bidirectionalcommunication.Thiscommunicationisaccomplishedwhentwoneighborslisteachother'sRouterIDsintheirHellopackets.Databasesynchronization.DatabaseDescription,LinkStateRequest,LinkStateUpdate,andLinkStateAcknowledgementpackets(describedinalatersection)areexchangedtoensurethatbothneighborshaveidenticalinformationintheirlink-statedatabases.Forthepurposesofthisprocess,oneneighborwillbecomethemasterandtheotherwillbecometheslave.Asthenameimplies,themasterwillcontroltheexchangeofDatabaseDescriptionpackets.Fulladjacency.11zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseNeighborStateDownAttemptInit2-Way.ExStartExchange.LoadingFull12zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15Forinternaluse路由器角色及典型网络拓扑13zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15Forinternaluse一条链路up的路由收敛过程1.接口UP，生成直连路由，loopback路由2.OSPF向自己所有邻居进入EXSTART状态协商M/S3.M发起ExchangeDD数据库描述的过程4.发现LSDB不同的路由器发起LSRequest，产生链路变化的路由器回LSUpdate5.其它路由器进行路由计算，生成路由表，FIB表14zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseLSA类型1RouterLSA(internalrouter)2NetworkLSA(DR)3NetworkSummaryLSA(ABR)4ASBRSummaryLSA5ASExternalLSA6GroupMembershipLSA7NSSAExternalLSA8ExternalAttributesLSA9OpaqueLSA(link-local)15zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseOSPF路由器角色和LSA区域0RouterLSANetworkLSAR2R3R1R5R2R3R1R4区域1区域2ABRABR其他AS到其他ASRouterLSANetworkLSARouterLSANetworkLSAASBRNetworkSummaryLSAASExternalLSAASBRLSANetworkSummaryLSAASExternalLSAASBRLSAASBRLSA(主机路由）16zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseOpaqueLSA(link-local)Sub-TLVTypeLengthName118LinkLocal/RemoteIdentifiers144LinkProtectionType15variableInterfaceSwitchingCapabilityDescriptor16variableSharedRiskLinkGroup在同一个area内传播17zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseGMPLSOpaqueLSA示例LSA_type=OpaqueLSA(10)---------------------(10.10.20.38)---------Linktype:16777216(1000000)---------LinkId:10.10.20.41---------TE-Metric:30---------Maxbandwidth:16---------Maxreservablebandwidth:16---------Unreservedbandwidth(16)Unreservedbandwidth[0]:16Unreservedbandwidth[1]:16Unreservedbandwidth[2]:16Unreservedbandwidth[3]:16Unreservedbandwidth[4]:16Unreservedbandwidth[5]:16Unreservedbandwidth[6]:16Unreservedbandwidth[7]:16---------Administrativegroup0---------Local/remoteid=16720771(0xff2383))/16720515(0xff2283)---------Linkprotectiontype:Unprotected---------Switchingcapabilities(100,5)SwitchingCapapability=TDMEncoding=SDHMAXLSPbandwidth[0]:16MAXLSPbandwidth[1]:16MAXLSPbandwidth[2]:16MAXLSPbandwidth[3]:16MAXLSPbandwidth[4]:16MAXLSPbandwidth[5]:16MAXLSPbandwidth[6]:16MAXLSPbandwidth[7]:16MINLSPbandwidth:1---------SRLG:30(0x1e)18zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseOSPF部分推荐资料RoutingTCP/IPVolIRFC4203(OSPFExtensionsinSupportofGMPLS)19zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseTraditionalMPLSOverviewMulti-ProtocolLabelSwitch数据平面定长交换（4字节标签）控制平面可使用多种协议(LDP,RSVP-TE,BGP)LDP的基本机制应用范围（MPLSL3VPN，L2VPN/VPLS，MPLS-TE）20zcwang©NokiaSiemensNetworksNSNAutomationTestPlatformTraining/zcwang/2008.09.15ForinternaluseLDP(LabelDistributeProtocol)的基本功能下游自主分发标签映射LSR4-LSR3&&LSR6Dest:192.168.1.0/24