On Characterizing PPStream: Measurement and Analysis of P2P IPTV under Large-Scale Broadcasting

Despite the recent and remarkable popularity of P2P IPTV systems, the study of their characteristics on largescale broadcasting is rare. In this paper, we have undertaken a measurement study on one of the most popular P2P IPTV systems, PPStream, during the 29th Olympics broadcasting. We deployed our dedicated measurement tool, PPS-Sniffer, under different network environments, and collected extensive data during a large number of events. We evaluate the playback delay, and the peering strategies towards local cluster. We also investigate the data scheduling, and its impact on the playback quality and the control overhead. To the best of our knowledge, results obtained in our study are unique and new as compared with existing work. Specifically, our study demonstrates that: (1) The playback delay is notable in Olympic channels, even for close peers. (2) Peering strategies of PPStream target mainly on the ISP level, and should exploit peers of local clusters to reduce the playback lag among close peers. (3) We unveil an overhead-quality tradeoff that sheds light on the design of future systems that can achieve a good balance. Our study aids the understanding of significant performance and design issues of PPStream, and is also useful for optimizing, modeling and the future design of P2P IPTV systems.