A White-Box Empirical Study of P2P-VoD Systems: Several Unconventional New Findings

P2P-VoD systems have gained tremendous popularity in recent years. While existing research is mostly based on theoretical or conventional assumptions, it is particularly valuable to understand and examine how these assumptions work in realistic environments, so as to set up a solid foundation for mechanism design and optimization possibilities. In this paper, we present a comprehensive measurement study of CoolFish, a real-world P2P-VoD system. Our measurement provides several new findings which are different from the traditional assumptions or observations: 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. We analyze the reasons for these results and provide suggestions for the further study of P2P-VoD services.