Real-time Sharing Of Multimedia System Research And Implementation Based On P2P Net

With the rapid development and popularization of Internet, P2P attracts more and more people' s attentions and becomes a hot spot in the computer net work technology. To compare P2P model and C/S model, reducing the server load and the network jam, changing the passive role in C/S structure, the client has the server and the client function in the P2P net work. With the improvement of the Internet bandwidth, it more possible for the transmission of high-quality real-time multimedia -also called streaming media via Internet. The codec technology for video and audio, together with the standardization of streaming-related protocols has facilitated this trend. The P2P applications of media streaming are gaining more and more attention.The paper deeply study of the P2P networks, media stream,the real-time Transport Protocol and the management of duplicate, realizing a real-time sharing of media stream system in P2P net with JXTA and JMF technology. The system referred to as P2PMS(peer to peer media stream) system. The System can not only share the local audio-visual documents, but also can share the capturing audio-video stream from the local. The systems completed real-time transmission with RTP, but the RTP need to use UDP or TCP transport layer for data transmission, streaming media transmission bandwidth needed is relatively high. Douching phenomenon is relatively common, TCP Retransmission mechanism of the RTP will not only increase bandwidth burden, but also seriously affect the real-time playback, so RTP use UDP protocol instead of the TCP. Copy resources management strategy makes the peer which has got sources shares the sources in the net. The strategy makes the media in P2P network of sources with user requests increased to speed up search and access to sources. It requires both a media sources in the local players, and also to other peer shared services. Media sources at the same time as a critical source can only be occupied by an application, so the system uses cloning technology which clones identical resources, in order to achieve the same resources multiple applications. In the choice of service providers, service providers from the system resources and real-time network load two aspects to assess service quality. Peers base on the evaluation of requests from the media to provide the sources, such as peer of the selected quality of service as a good point of service, in order to obtain good results and broadcast network load balancing.Experimental research shows that the system of the media achieves the real-time sharing of resources and balances the network bandwidth, and as such points of the increase, with a copy to increase resources to speed up the search speed of resources. System design model to provide a reference for P2P media applications and has good practical value and theoretical research value.