中文摘要：

为提高基于P2P流媒体系统的服务质量,提出了一种基于最小价值的流媒体缓存替换算法SDU。研究了现有的缓存替换算法,通过对现有的缓存替换算法的理解、研究和分析,得出了现有的缓存替换算法在P2P网络节点间效率不高。对P2P网络和流媒体系统的分析研究,提出了SDU算法。该算法综合考虑了副本的供求关系、数据的紧迫度和数据的字节有用性。仿真实验结果表明,该替换算法有效地降低系统的启动延迟和服务器的负载,能够获得较好的性能。

英文摘要：

In order to promote the quality of service（QoS） of streaming system based on P2P technology,the smallest cache value（SDU） is proposed.First the existing cache replacement algorithm is researched.Based on these,by analyzing the existing cache replacement algorithm we can obtain that the efficiency of the existing cache replacement is not high in the P2P network.Then the P2P network and streaming media system are analyzed.And then SDU algorithm is proposed.SDU considers copy＇s supply and demand, data＇s necessitous degree and bytes benefit of streaming media.Simulation experimental results show this strategy can reduce consumption of server＇s load effectively,and obtain better performance.