基于网络代价的流媒体缓存策略研究

Study of Network Cost Based Cache Policy for Streaming Media

该文构造了一种新的流媒体缓存效用函数,该函数综合考虑流媒体节目的流行度特性及传输网络的代价参数;设计了一种针对多视频服务器、基于网络代价的流媒体缓存分配与替换算法(Network Cost Based cache allocation and replacement algorithm,NCB)。仿真实验结果显示,NCB算法有效提高了缓存命中率,降低了传送流媒体所消耗的总体网络代价;该算法在网络结构复杂、节目数量庞大的Internet流媒体应用环境中表现出较优越的性能。

By taking the popularity character of the media program and the cost of the transmission network into consideration, a novel caching utility function is proposed. A Network Cost Based streaming media cache allocation and replacement （NCB） algorithm is designed for multi-server streaming application. Simulation proves that, by employing the NCB algorithm, the cache hit rate can be improved obviously and the total network cost can be decreased ~fectively. In the Internet streaming application environment, where the network connections between content servers and caching proxy are heterogeneous, the amount of streaming programs is huge, the NCB shows good performance.