Abstract: Peer-to-Peer (P2P) technology has recently been employed to deliver large-scale video multicast services at minimum server infrastructure cost. A number of commercial systems have been successfully deployed on the Internet to stream live and on-demand videos to millions of users.

In order to gain insight into the success of P2P video streaming, we have undertaken analytical study to expose the fundamental characteristics and limitations of generic P2P video streaming systems. To characterize the maximum supportable streaming rate, we develop a simple stochastic fluid model that accounts for many of the essential features of a P2P streaming system, including the peers’ realtime demand for content, peer churn (peers joining and leaving), peers with heterogeneous upload capacity, limited infrastructure capacity, and peer buffering and playback delay. The model is tractable, providing closed-form expressions that can be used to shed insight on the fundamental behavior of P2P streaming systems.

Most of existing P2P live streaming systems suffer from much longer start-up delays than video services provided by cable companies. While P2P sharing is very efficient for bandwidth sensitive applications, it imposes a fundamental performance limit for delay sensitive applications. We theoretically study the inherent delay limit imposed by P2P video sharing and derive the minimum delay bounds of P2P live video streaming systems. We show that the bandwidth heterogeneity among peers can be exploited to significantly improve the delay performance of all peers. We further propose a simple snow-ball streaming algorithm to approach the minimum delay bounds.

Bio:

Dr. Yong Liu received his bachelor and master degree from the University of Science and Technology of China, in 1994 and 1997 respectively. He graduated with Ph.D degree from ECE Dept. at University of Massachusetts, Amherst in 2002. His Ph.D thesis advisor was Prof. Weibo Gong. From February 2002 to February 2005, he worked as a Postdoc in Computer Networks Research Group at UMass. In March 2005, he joined the ECE department of Polytechnic University as an assistant professor. His current research interest includes: overlay/P2P networks, network measurement and robust network design. One of his papers on P2P video streaming system measurement was recently awarded the Best Paper in Multimedia Communications by the IEEE Communications Society. More information about his research and teaching is available at:

http://eeweb.poly.edu/faculty/yongliu/