Design And Implementation Of Streaming Media Proxy System

Along with the development of computer networks and multimedia, the streaming media is becoming the main part of Internet application. It promotes the innovation of the overall structure of Internet and stimulates the development of the information economy. The streaming media play a leading role in spread of Internet media. Applications of multimedia such as video on demand, video conference, Network TV, broadcast network and so on are becoming more and more popular on. All these applications have great practical values.The wide popularity of the applications of streaming media increases the demand for the server of streaming media. Especially in broadcast network, the server of multimedia not only need to code and decode pictures but also need to response the clients' requirements in time, and send media data. All these requirements easily form a bottleneck of the server of streaming media.It's the key of the problem to use a single node to distribute the tasks of the tradition streaming media server. It can decrease the time of client player in launch delay and save part of the network bandwidth through setting the streaming media proxy server system between client and server. It also can response more clients' demand. because the streaming media proxy server systems can be cascaded. The implementations of streaming media transmission and caching technology are very important in building streaming media proxy server systems.The technology of streaming media transmission is mainly achieved through three real time protocols. RTSP is a protocol which is used to represent and control the streaming media. It controls the send of the real time data but don't send data. RTP is a real time transport protocol which is used to transport the streaming media data in time in peer to peer communications or multicast networks. It neither provides any mechanisms that assure the data send in sequence nor provide the flow control and congestion control. All these services are provided by the real time transport control protocol—RTCP.Almost all RTSP communications are achieved through building interactive modules of RTSP in the whole streaming media proxy server system. In the modules of data sending and caching the system process the two applications apart according to the different requirements of video on demand and video broadcast. The service of media on demand set some hot programs and when users demand such hot programs the streaming media proxy server system send RTP packets to clients directly from local instead of through the media server through which the system can improve the performance and save network resources.