DATE: Thursday, March 13, 2003
TIME: Noon - 1 pm
PLACE: Wean Hall 8220

Venkata Padmanabhan
Microsoft Research

Resilient Peer-to-Peer Streaming

We consider the problem of distributing "live" streaming media content to a potentially large and highly dynamic population of hosts. Peer-to-peer content distribution is attractive in this setting because the bandwidth available to serve content scales with demand. A key challenge, however, is making content distribution robust to peer transience. Our approach to providing robustness is to introduce redundancy, both in network paths and in data. We use multiple, diverse distribution trees to provide redundancy in network paths and multiple description coding (MDC) to provide redundancy in data.

We present a simple tree management algorithm that provides the necessary path diversity and describe an adaptation framework for MDC based on scalable receiver feedback. We evaluate these using MDC applied to real video data coupled with actual usage traces from a major news site that experienced a large flash crowd for live streaming content. Our results show significant benefits in using multiple distribution trees and MDC. We also present a method for combining MDC with traditional layering to accommodate bandwidth heterogeneity. Our layered MDC construction enables a novel hybrid parent- and child-driven congestion control scheme appropriate for situations where the last-hop links of end-hosts are prone to congestion.

(Joint work with Phil Chou and Helen Wang)

Venkat Padmanabhan is a Researcher in the Systems and Networking group at Microsoft Research, where he has been since receiving his Ph.D. in Computer Science from U.C. Berkeley in 1998. His research interests include wide-area and wireless networking, Internet performance, and mobile computing. His recent work has focused on peer-to-peer content distribution, multi-hop wireless networks, wireless user tracking, and Internet geography. Venkat serves on the editorial boards of the IEEE/ACM Transactions on Networking and the IEEE Transactions on Mobile Computing, was Tutorials Co-Chair for ACM Mobicom 2000, and has served on the program committees of several conferences including ACM Mobicom, IEEE Infocom, and ACM Sigmetrics. He also holds affiliate faculty appointments in the CS and EE departments at the University of Washington, where he has taught and served on student thesis committees. Venkat can be reached on the web at

For Further Seminar Info: