P2P Live Streaming: Practice and Theory

August 30, 2006
Keith Ross | Polytechnic University (Brooklyn, NY)

With the widespread adoption of broadband residential access, live video streaming may be the next disruptive IP communication technology. As an indication of the potential of live video streaming, recently a commercial P2P streaming system broadcasted the 2006 Chinese New Year’s celebration to over 200,000 users, generating an aggregate bit rate in the vicinity of 100 gigabits/sec. CoolStreaming, PPlive, and ppstream are among the most successful deployments, all of which use pull-driven meshed-based designs.

In the first part of this talk we will describe the general architectural characteristics of pull-driven architectures. We will then summarize the results of a recent measurement study of PPLive. As part of the measurement study, we have developed a PPLive crawler, which is used to study the global characteristics of a large-scale P2P streaming system. We have also collected extensive packet traces for both campus and residential access. These active and passive measurements provide insight into user behavior, traffic overhead and redundancy, and peer partnership characteristics.

In the second part of the talk, we discuss a simple but insightful mathematical model for P2P live streaming. The model accounts for real-time demand for content, peer churn, heterogeneous upload capacity, peer buffering and playback delay. The model shows that performance is largely determined by a critical value. It also shows that large systems have better performance than small systems since they are more resilient to peer churn. Finally, the model shows that buffering can dramatically improve performance in the critical region.

Speaker Details

Professor Ross is the Leonard J. Shustek Chair Professor in Computer Science at Polytechnic Institute of NYU since January 2003. Professor Ross has worked in peer-to-peer networking, Internet measurement, video streaming, Web caching, multi-service loss networks, content distribution networks, network security, voice over IP, optimization, queuing theory, and Markov decision processes. He is an IEEE Fellow, associate editor for IEEE/ACM Transactions on Networking, has served as PC chair for several networking and multimedia conferences. He has also served as an advisor to the Federal Trade Commission on P2P file sharing. Professor Ross is co-author (with James F. Kurose) of the popular textbook, Computer Networking: A Top-Down Approach Featuring the Internet, published by Addison-Wesley (fifth edition 2009). It is the most popular textbook on computer networks in CS departments, both nationally and internationally; it has been translated into twelve languages. Professor Ross is also the author of the research monograph, Multiservice Loss Models for Broadband Communication Networks, published by Springer in 1995.