【技術課件】多媒體技術

1、q 廣播廣播：將源端數(shù)據(jù)發(fā)送到一個網(wǎng)絡中的：將源端數(shù)據(jù)發(fā)送到一個網(wǎng)絡中的所有主機的傳播方式。廣播使用廣播地址。所有主機的傳播方式。廣播使用廣播地址。q 單播單播：將源端數(shù)據(jù)發(fā)送到網(wǎng)絡中的某個：將源端數(shù)據(jù)發(fā)送到網(wǎng)絡中的某個特定主機的傳播方式。單播使用特定主機特定主機的傳播方式。單播使用特定主機地址。地址。q 組播組播：將源端數(shù)據(jù)發(fā)送到網(wǎng)絡中的一組：將源端數(shù)據(jù)發(fā)送到網(wǎng)絡中的一組主機的傳播方式。組播使用組地址。主機的傳播方式。組播使用組地址。SrcSrc組播：一種有效節(jié)省網(wǎng)絡帶寬的傳輸方式。組播：一種有效節(jié)省網(wǎng)絡帶寬的傳輸方式。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