File swarming (or file sharing) is one of the most important applications in P2P networks. One classical example of file swarming applications is the well-known BitTorrent (BT) protocol. In this talk, we first present the BT protocol, then we propose a stochastic framework to analyze a file swarming system under realistic setting: constraints in upload/download capacity, collaboration among peers and incentive for chunk exchange. We first extend the results in the coupon system by Massoulie and we provide a tighter performance bound. Then we generalize the coupon system by considering peers with limited upload and download capacity. We illustrate the well-known last-piece problem, and show the effectiveness of using forward error-correction (FEC) code and/or multiple requests to improve the performance. Lastly, we propose a framework to analyze an incentive-based file swarming system. The stochastic framework we propose can serve as a basis for other researchers to analyze and design more advanced features of file swarming systems.
John C.S Lui is currently the chairman of the Department of Computer Science & Engineering at The Chinese University of Hong Kong. He received his Ph.D. in Computer Science from UCLA. He has been a visiting professor in computer science departments at UCLA, Columbia University, University of Maryland at College Park, Purdue University, University of Massachusetts at Amherst and Universit degli Studi di Torino in Italy. His current research interests are in theoretic/applied topics in data networks, distributed multimedia systems, network security, OS design issues and mathematical optimization and performance evaluation theory. John received various departmental teaching awards and the CUHK Vice-Chancellor's Exemplary Teaching Award in 2001. He is a co-recipient of the IFIP WG 7.3 Performance 2005 and IEEE/IFIP NOMS 2006 Best Paper Awards. He is on the editorial board of IEEE Transactions on Computers, IEEE Transactions on Parallel & Distributed Systems, Performance Evaluation Journal and International Journal on Network Security. He is currently the vice president of the ACM SIGMETRICS. His personal interests include films and general reading.