Diagnosing Network-Wide P2P Live Streaming Inefficiencies

Large-scale live peer-to-peer (P2P) streaming applications have been successfully deployed in today´s Internet. While they can accommodate millions of users simultaneously with hundreds of channels of programming, there still commonly exist channels and times where and when the streaming quality is unsatisfactory. In this paper, based on more than two terabytes and one year worth of live traces from UUSee, a large-scale commercial P2P live streaming system, we show an in-depth network-wide diagnosis of streaming inefficiencies, commonly present in mesh-based P2P streaming systems. We first identify an evolutionary pattern of low streaming quality in the system and the distribution of streaming inefficiencies across various streaming channels. We then carry out an extensive investigation to explore the causes to such streaming inefficiencies over different times and across different channels at specific times. The original discoveries we have brought forward include the two-sided effects of peer population on the streaming quality in a channel, the significant impact of inter-peer bandwidth bottlenecks at peak times, and the inefficient utilization of server capacities across concurrent channels. We conclude with a number of suggestions to improve real-world large-scale P2P streaming.