Performance Analysis of Caching Strategies for Proxy-Assisted VOD Services

Proxy caching strategies, especially prefix caching and interval caching, are commonly used in video-on-demand (VOD) systems to improve both system performance and the playback experience of users. However, because these caching strategies are designed for homogeneous clients, they do not perform well in the real world where clients are heterogeneous (i.e., different sizes of client-side buffers). In this paper, we investigate the problems caused by heterogeneous clients, and then analyze the theoretical performance of these caching strategies. Based on these analytical results, we derive some rules for a proxy to determine which caching strategy should be applied so that it can maximize system performance.