IP Multicast Research And Application

The algorithm of IP multicast routing and the application of multicast in network multimedia are researched in this paper.First,the paper gives an overview on the basic theory of multicast,including multicast routing algorithms,multicast routing protocols and Internet Group Management Protocols. On the basis of this,a new algorithm of selecting multicast route was brought up,which applies in the case that there are only one multicast sender and many receivers. The algorithm is independent of the unicast routing protocol. When the receiver wants to join in a multicast group,it sends a request message to the sender with a TCP connection. The request message gets to the sender and the sender answers for it with a confirmed message. During the confirmed message returning to the receiver,the router along the pass forms the multicast routing information according to the confirmed message.Second,the paper introduces the theory of Real-time Transport Protocol (RTF) and the DirectShow technology. Using RTF,with the help of DirectShow's frame,two Filters are programmed to send and receive multicasting data in the application research. One filter,a Tenderer filter,is used in the sender side to send audio file or real-time audio to the network. Another,a source filter,is used in the receiver side to receive audio stream from the network.Finally,a summary is given to show what have done in the paper. The drawback of the paper and the direction of further research are pointed out.