SDI Seminar

Speaker: Ken Birman, Cornell University

Date: March 18, 1999
Time: Noon
Place: Wean Hall 8220

Bimodal Multicast


The virtual synchrony model for reliable group multicast has become widely accepted, and supports a very powerful form of fault-tolerance, but also encounters limitations in settings combining a need for high bandwidth multicasts with stable throughput. A new protocol called the "Bimodal Multicast" is proposed; it offers a very different reliability guarantee which overcomes the instability and scaling limitations of the virtual synchrony model. We'll look at the nature of the bimodal property (which is probabilistic), at applications for which this property is a good match, and at the behavior of the protocol in realistic local and wide-area settings.


Ken Birman is Professor of Computer Science at Cornell University where he has studied distributed systems security and reliability issues since 1981. In 1987 he founded a company, Isis Distributed Systems, which developed robust software solutions for stock exchanges, air traffic control, and factory automation. Isis was acquired by Stratus Computer in 1993, and Dr. Birman recently founded a second company, Reliable Network Solutions Inc. He is the author of one book, "Building Secure and Reliable Network Applications", (Prentice Hall and Manning Publishing Company; 1997), and has written many articles on the subject, including one that appeared in Scientific American in May, 1996. At Cornell, Dr. Birman heads the Horus and Ensemble projects. Dr. Birman was also Editor in Chief of ACM Transactions on Computer Systems from 1993-1998 and is a Fellow of the ACM.