12:45 PM, Thursday, January 24th, 2002
Room 104, Gates Computer Science Building

WEBRC: Wave and Equation Based Rate Control

Vivek Goyal and Michael Luby
Digital Fountain

About the talk:

Wave and Equation Based Rate Control (WEBRC) is a multi-rate congestion control protocol that is most advantageous with multicast and works equally well with unicast. Like previous multi-rate congestion control protocols, WEBRC is receiver-driven, and thus there is no impact on the sender when additional receivers join a session. Furthermore, the reception rate of each receiver in a session adjusts to the available bandwidth between the receiver and the sender independently of other receivers, and thus receivers on paths with more available bandwidth are not slowed down by receivers on paths with less available bandwidth.

The key innovations in the design of WEBRC are a natural and compelling definition of a multicast round trip time (MRTT), the idea of waves, and the introduction of a multi-rate congestion control protocol that is equation based.

The main advantages of WEBRC over previous techniques are that the amount of IGMP and PIM SM control traffic is minimal, the number of multicast channels used is minimal, the self-adjusting receiver protocol fine-tunes the reception rate to the available bandwidth, loss due to buffer overflow is minimized, and the fairness to TCP is very good. In addition, WEBRC has the benefit that, due to the use of the MRTT, a receiver's reception rate can be coordinated and improved by other receivers in the same vicinity.

About the speaker:

Vivek Goyal has been a Senior Research Engineer with Digital Fountain since May 2001. Prior to that, he received the Ph.D. degree from the University of California, Berkeley, and spent three years at Lucent Technologies' Bell Labs.

Vivek's research interests include source coding theory, quantization theory, and practical, robust network content delivery.