Research And Implementation Of A Proxy Cache For Streaming Media

With the development of network and multimedia technology, streaming media applications have become more and more popular. Accordingly, in order to adapt to the real-time demands of streaming media applications and reduce the network bandwidth bottleneck, streaming media cache technology merges as the time demand.. Streaming media cache can be deployed and implemented between the clients and the servers based on the proxy mechanism. Thus it will not only reduce the start-up delay of the clients' player in the event of a cache hit but also save network bandwidth to some extent. The implementation of streaming media transport and cache management technologies is very vital for constructing streaming media cache.RTSP is a streaming media presentation control protocol used to manage the delivery of real-time data. It doesn't transfer streaming data by itself . RTP is used to transfer streaming media data on the unicast or multicast networks but it can not provide reliable transport mechanism with transferring data packets orderly. It is also not able to provide flow control and congestion control which can be implemented by RTCP .In the implementation of streaming media cache, cache can act as a bridge between the clients and the servers by constructing a RTSP proxy framework. Almost all the RTSP communication between the clients and the servers will be transmitted by the streaming media cache. At the same time, RTP transfer module can deal with the RTP packets according to their inquiry results . On one side , cache can transfer RTP packets to clients directly from the local disk and implement the function of cache prefetching based on PLAY method in RTSP in the event of CACHE HIT. On the other side , cache can transfer RTP packets to clients from original servers and store a copy of the streaming file in the local disk in the event of CACHE MISS based on the caching policies simultaneously.As for the caching management and replacement policies, SQUID can provide classic realization model. Streaming media cache can be implemented efficiently by communicating with SQUID and utilizing caching replacement policies of SQUID.