Chunming Qiao - Mon, Feb 23
Lab for Advanced Network Design, Analysis, and Research (LANDER)
State University of New York (SUNY) at Buffalo
videorecording - use Windows Explorer to access the files (wmv, rm)

Some Insights Into the TCP Performance in Optical Burst Switched (OBS) Networks

Optical Burst Switching (OBS) is a promising paradigm for the next generation Optical Internet which integrates IP and WDM. During the last several years, OBS has received a considerable amount of attention from the research community around the world. Since TCP traffic is and may remain as the most popular traffic type in the Internet, it is important to evaluate the interactions between the TCP congestion control mechanism and OBS-specific mechanisms such as burst assembly/disassembly a the edge and buffer-less burst switching in the core.

In this talk, we first briefly describe the OBS paradigm. We then identify various OBS-specific factors that result in TCP throughput gains and penalties due to burst assembly and bufferless burst switching. Our analysis and simulations show that while TCP SACK performs best in OBS networks. TCP New-Reno, which improves Reno using fast retransmission in responding to partial ACKs, may perform worse than TCP Reno.

The above three most popular TCP implementations react to a Time Out (TO) loss in the same way (i.e., using Slow Start). In OBS networks, where a burst may contain all the packets from one sending round, and a burst loss occurs mainly due to contention instead of buffer overflow, a TO event may be a false TO (or FTO) in that it may no longer imply heavy congestion. Such FTOs may significantly degrade the performance of all these three TCP implementations.  Accordingly, we also propose a new TCP implementation called Burst TCP (or BTCP), which can improve over the existing TCP implementations significantly by detecting and reacting to the FTOs properly.

Bio

Dr. Chunming Qiao directs the Lab for Advanced Network Design, Analysis, and Research (LANDER) at the State University of New York (SUNY) at Buffalo, which conducts cutting-edge research work on optical networks, wireless networks, survivable networks, and TCP/IP technologies. He has published more than one hundred forty papers in leading technical journals and conference proceedings. His pioneering research on Optical Internet, in particular, the optical burst switching (OBS) paradigm is internationally acclaimed. In addition, his work on integrated cellular and ad hoc relaying systems (iCAR) is recognized as the harbinger for today's push towards the convergence between heterogeneous wireless technologies, and has been featured in Businessweek, Wireless Europe and NewScientists. His research has been sponsored by the National Science Foundation (including two ITR awards), Alcatel, Nokia, Nortel Networks, Telcordia and ITRI (Industrial Technology Research Institute in Taiwan).

Dr. Qiao have given several keynotes, tutorials and invited talks on the above research topics. He is on the editorial board of several journals and magazines including IEEE/ACM Transactions on Networking (ToN), and IEEE Communications Magazine, and have guest-edited several IEEE JSAC and ACM/Baltzer's Mobile Networks and Applications (MONET) issues. He has chaired and co-chaired a dozen of international conferences and workshops including the High-Speed Networking Workshop (formerly GBN) at IEEE Infocom'01 and Infocom'02, Opticomm'02, and the symposium on Optical Networks at ICC'03. He is currently the vice chair of the IEEE Technical Committee on High Speed Networks (formerly TCGN).