A hybrid content delivery network combining complementary advantages of CDN and P2P called HyCDN for streaming media was presented. The CVCR4P2P (Comprehensive Value Cache Replacement Algorithm for P2P) algorithm was proposed for the peers inside domain, which considers bytes benefit of prefix data, transmission cost and access rate of streaming media. Another algorithm,DSA4ProxyC (Dynamic Scheduling Algorithm for Proxy Caching), which joints the proxy caching and server scheduling strategies for proxies between domain was also shown. It employs the scheme of cache allocation based on the current batching interval that has non-zero requests, which can be updated periodically according to the popularity of streaming media object The principle is obeyed that the data cached for each streaming media object are in proportion to their popularity at the proxy server. Theoretical analysis and simulation results show that the hybrid dynamic scheduling can effectively reduce server and network bandwidth usage,and also has a very good adaptability for the variety of the request arrival rate.%介绍了一种结合了CDN和P2P互补优势的流媒体混合内容分发网络(HyCDN).针对HyCDN不同区域提出了相应的缓存算法,域内用户端综合考虑了流媒体前缀字节的有用性、文件的传输代价及点播热度,在此基础上提出缓存替换算法(Comprehensive Value Cache Replacement Algorithm for P2P,CVCR4P2P)；对域间边缘服务器采用补丁预取与调度算法(Dynamic Scheduling Algorithm for Proxy Caching,DSA4ProxyC),通过基于用户访问情况自适应伸缩缓存的分配方案,使流媒体后缀部分在边缘服务器中缓存的数据段与其流行度成正比.理论分析及实验结果表明,混合流媒体缓存调度策略的实施能有效地降低骨干网络带宽资源消耗,对用户请求到达速率的变化具有良好的适应性.
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