摘要 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。
Abstract: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 effectively. 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.