The key problem is to design network protocols for video that achieve efficiency by statistically multiplexing the network resources, but avoid degradation in video quality caused due to packet losses. We have developed protocols for transmitting stored and live VBR video streams that meet this objectives.

Since end-to-end delay requirements for stored video are not very stringent, our protocol for stored video transport shapes the traffic such that the rate changes are regular, infrequent, and predictable. The protocol then combines open-loop and feedback-based control to: (1) provide heterogeneous QoS to clients in networking environments consisting of switches that may not have any scheduling support; and (2) migrate the functionality of discarding packets, in the event of congestion, to the sources which understand the semantics of the data. The protocol is efficient, makes very few assumptions about the underlying network, is realizable on current switching hardware (supporting FCFS scheduling), and is completely integrated with the architecture of a multimedia server.

Our network layer protocol for live video transport is based on a per link, hop-by-hop flow control algorithm. It: (1) minimizes buffer requirement by adaptively allocating buffer at the switches while ensuring that packet losses do not occur in the network, and (2) minimizes end-to-end delay and jitter of frames.

Representative Publications:

1. P. Goyal and H.M. Vin, Network Algorithms and Protocol for Multimedia Servers, In Proceedings of INFOCOM'96, San Francisco, Pages 1371-1379, March 1996 [ Abstract | Paper ]

2. P. Goyal, H. M. Vin, C. Shen, and P.J. Shenoy, A Reliable, Adaptive Network Protocol for Video Transport, In Proceedings of INFOCOM'96, San Francisco, Pages 1080-1090, March 1996 [ Abstract | Paper ]