【技术课件】多媒体技术

1、q 广播广播：将源端数据发送到一个网络中的：将源端数据发送到一个网络中的所有主机的传播方式。广播使用广播地址。所有主机的传播方式。广播使用广播地址。q 单播单播：将源端数据发送到网络中的某个：将源端数据发送到网络中的某个特定主机的传播方式。单播使用特定主机特定主机的传播方式。单播使用特定主机地址。地址。q 组播组播：将源端数据发送到网络中的一组：将源端数据发送到网络中的一组主机的传播方式。组播使用组地址。主机的传播方式。组播使用组地址。SrcSrc组播：一种有效节省网络带宽的传输方式。组播：一种有效节省网络带宽的传输方式。HostsRouters1 1 1 0Group IDLAN multi

2、cast address0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 1 1 1 1 0 01 1 1 028 bits23 bitsIP multicast addressGroup bitHostsRoutersService modelMulticast routing protocols(various)QRouters:Hosts:QGGGGRouters:Hosts:HostsRoutersService modelHost-to-router protocol(IGMP)Multicast routing protocolsGGSGGGSGGGSPr

3、une (s,g)Prune (s,g)GGraft (s,g)Graft (s,g)GGSGGReport (g)GGSGGHost/routerMBone routerPhysical linkTunnelPart of MBoneRRRHRHRRHSource 1Receiver 1Receiver 2MOSPF: ExampleZWQTSource 1Receiver 1Receiver 2Link Failure/Topology ChangeZWQTXSource 1Receiver 1Receiver 2Group Membership ChangeZWQTReceiver 3R

4、outerSourceReceiverSRRRRRSSRouterSourceReceiverSSSRRRRRSource 1Receiver 1Receiver 2PIM Example: Build Shared Tree(*,G)Receiver 3(*,G)(*,G)(*,G)(*,G)(*,G)Join messagetoward RPShared tree after R1,R2 joinRPSource 1Receiver 1Receiver 2Data Encapsulated in Register(*,G)Receiver 3(*,G)(*,G)(*,G)(*,G)(*,G

5、)Unicast encapsulated data packet to RP in RegisterRPRP de-capsulates, forwards down shared treeSource 1Receiver 1Receiver 2RP Send Join to High Rate SourceReceiver 3(S1,G)RPJoin messagetoward S1Shared treeSource 1Receiver 1Receiver 2Build Source-Specific Distribution TreeReceiver 3Join messagesShared TreeRPBuild source-sp