关键词: peer-to-peer（P2P）, 视频点播（VoD）, 流媒体, P2P评价模型

Abstract: P2P-VoD systems have gained tremendous popularity in recent years. Existing research is mostly based on the traditional theoretical assumptions. However, what is the performance of these assumptions is not known in the real world. It is particularly valuable to understand how the real-world system works. This paper presents a comprehensive measurement and analysis on CoolFish, a real deployed P2P-VoD system, and proposes some statistical models different from the traditional observations on user behavior: the access pattern does not match Poisson distribution; session time does not have positive correlation with movie popularity; jump frequency does not have a negative correlation with movie popularity as assumed in previous studies. This paper analyzes the reasons for these results.

Key words: peer-to-peer (P2P), video-on-demand (VoD), streaming, P2P evaluation model