Effect of Different Marking Strategies on Explicit Congestion Notification (ECN) Performance

Dr. Jogesh Muppala Department of Computer Science, Hong Kong University of Science and Technology

The congestion control mechanisms built into the Transmission Control Protocol (TCP) use packet drops as a means to detect congestion occurring in the network. Unnecessary packet drops lead to poor performance for low-bandwidth delay-sensitive applications. Explicit Congestion Notification (ECN) is proposed as a mechanism to provide feedback to the sources about impending congestion in the routers without the need to drop packets. This requires the ECN bit of the IP packet to be marked at the router based on mechanisms like Random Early Detection (RED) to identify congestion. In this seminar, we examine three different marking strategies: mark-tail, mark-front and mark-random. The throughput performance of ECN flows and the unfairness among the ECN flows are examined. We also study the interaction between ECN and non-ECN flows.

Speaker's biography:

Dr. Muppala received the Ph. D. degree in Electrical Engineering from Duke University, Durham, North Carolina, in 1991. He is currently an associate professor in the Department of Computer Science, Hong Kong University of Science and Technology. He was previously a member of the technical staff at Software Productivity Consortium (Herndon, Virginia, USA) from 1991 to 1992, where he was involved in the development of modelling techniques for systems and software. While at Duke University, he participated in the development of two modelling tools: the Stochastic Petri Net Package (SPNP) and the symbolic Hierarchical Automated Reliability and Performance Evaluator (SHARPE), both of which are now being used in several universities and in industry in the USA.

Maintained by rbennett@cs.ucl.ac.uk