Research And Simulation Design Of Proxy Cache Replacement Algorithm Based On QoS

Network technology developed rapidly today, the portion of streaming media ininformation transfer of network is becoming larger and larger. And because of the growth ofnetwork application, and Internet totally assigns such as WAN, the congested phenomenon ofthe network grows in intensity too. On one hand, we hope to watch more clear and vividmedia program; On the other hand, we have to waste a lot of time on watching video/audiocontents transmition. To solve this contradiction, streaming media technology is proposed.Because it is unnecessary download the video/audio contents to local, for its continuous、real-time and time-ordered characters, streaming media technique is widely applied in ourlife and work.In order to improve streaming media transmission performance of data in WAN, proxycache server is added into content distribute system in streaming media. Set proxy cache atthe edge of network, and useful streaming media data is saved on the acting server, the proxycache server will be asked to provide service to shorten the delay of starting for the users.Because the capacity of the proxy cache server is limited, the most useful streaming mediadata must be saved on the proxy cache server to guarantee the server can give full play to therole of it. So proxy cache replacement algorithm determines performance of the acting serverdirectly.This algorithm maked streaming media popularity, PSNR and QoS quality factors add inpopularity predict proxy cache replacement algorithm of streaming media and improve basedon traditional proxy cache replacement algorithm and then construct gain model. Experimentsshow that the improved algorithm can much more directly reflect the proxy serve service ofefficiency and user-services and technique requirements of agent server. The delay that theclient click video and streaming media in propagation of packet loss rate are reduced and theneffectively improve proxy server system performance.The experimental results show that new cache replacement algorithm adds three factors: again popularity, PSNR, and QoS to improve the efficiency and performance of proxy cachereplacement in the Construction of the gain model.The proxy cache system has a better system throughput, higher resolution video images,less delay through this algorithm.It is aneffective cache replacement algorithm for streaming media; In addition, the algorithm also hasgood stability and adaptability.