Research On The IP Multicast Under The P2P Internet For Streaming Media

As the video streaming applications in the IP network whose service model is "try its best effort to send", we need solve some problems such as the fluctuation and isomer of the network bandwidth , the data packet delay, the jitter and loss, as well as the transmission errors. So the video streaming has been a hot research field. Traditional C/S media service system can no longer meet the needs of huge scale users. We need a new network architecture to meet the streaming-media service system for network bandwidth and server performance requirements. Researchers have proposed using the technology of IP multicast, application layer multicast (ALM), and content distributed network (CDN) etc. Although each has its strong point among these technologies, however, transmit in the IP network service mode, any network transmission technologies is difficult to take on the application of the extensive streaming media. However, recently, the innovation of the IP multicast and P2P technology speed the application of the extensive streaming media. Viewing the development of the current streaming media application, the integration of the IP multicast and the P2P technology will become a mainstream program. This hybrid technology can greatly improve the efficiency, flexibility and adaptability of the multicast.This paper first introduced the key technologies about stream-media in Internet currently. Then we compared the IP multicast and the P2P multicast, analyzed their superiority and the flaw. In view of the present network, there exist some multicast isolated islands and especial multicast users etc, their data can not share from each other. So we proposed that using P2P transmission to connect the isolated islands. For instance, we elected an agent member DM from multicast island B linked to a member from multicast island A. So the agent member can form its own multicast grouping in the region of B. We elected a member act as the designate member from each multicast isolated island. When such isolate islands or region connect become more, the designate members use P2P transmission to construct an application layer multicast tree. Meanwhile, we elected a member as a control member from each isolated multicast island to deal with control message on the ALM. The control node implemented the congestion control in the transmitting end and the receiving end, to avoid congestion of the agent member. In the algorithm, we computed the priority strategy of nodes from the isolate island for multicast to select the appropriate agent nodes. We also solved the join of the node from the ALM tree, dealt with the normal apartment and deviant apartment. At last, in view of the incapability of the elected DM, we proposed the optimize project. In this way, DM was not only the receiver in the network layer multicast, but also was the receiver in the P2P application layer. The system was scalable, robust and cost-effective.