Reserch On Multicast And Application Of Multicast In Shanghai Broadband Network

In these years, with the explosive development of Internet, not only the rapid growth of the broadband subscribers and the increase in the bandwith of the network has occurred,but also a lot of new applications in Internet have occurred, many of which are multimedia applications that need quite big bandwidth, such as network video conferences, network audio/video broadcast, video on demand, IPTV and so on. For these new applications, traditional unicast technology (one to one) and broadcast technology (one to multi) will take great pressure on the network.Multicast is a technology that can send data to multiple receivers in an effieient and extendable way.Mulicast source sends packets to a specific multicast group, and only the address which belongs to this multicast group can receives the packets.In applications in video,there is only one multicast source.The multipling growth of the users will not upgrade the network bandwith.Because no matter how many target addresses are,there is only one video steam in the bone network.It calls that"send once,boardcast in the group". Multicast technology impoves the efficiency of data sending and reduces the possibilities of the traffic congestion in bone network.The paper discussed the multicast technology and analyzed the technology of IGMP,multicast routing protocols and multicast routing protocols algorithms.Then the paper rised the problem of the deployment of multicast in Shanghai broadband network.To discuss this problem,the paper analyzed the two models of multicast, the policy and method of multicast to be deployed on each layer of network,the the choice of multicast duplicate point.Finally,according to the deployment of multicast and the overview of the broadband network in Shanghai,this paper rised the methods of the deployment of IPTV in Shanghai,which decided by the IPTV development scale.