PPStream characterization: Measurement of P2P live streaming during Olympics

P2P streaming technique is spreading widely and the study of its characteristics on large-scale broadcasting is meaningful and important. In this paper, we have undertaken a measurement on one of the most popular P2P IPTV systems, PPStream, during the 29^th Beijing Olympics. We collected extensive data traces under different network environments. New and unique observations are presented in our study as compared with existing measurements. Specifically, our results show that 1.) The playback delay is more remarkable in Olympics channels; 2.) Parent overlap is extremely small even for peers very nearby; 3.) The change of buffering fluctuates periodically in both Olympic and ordinary channels; 4.) Smaller scheduling unit is employed in Olympic channels with potential inefficiency. Measurement results obtained in our study bring to light significant performance and design issues of P2P live streaming systems during large-scale broadcasting, and are valuable in better understanding, optimizing and modeling of such systems.