SDI Seminar

Speaker: Hui Zhang

Fundamental Limits and Tradeoffs of Providing Deterministic Guarantees to VBR Video Traffic

Date: May 4, 1995

Abstract: Compressed video is one of the most important traffic types in future integrated services networks. However, a network service that supports delay-sensitive video imposes many problems since compressed video sources are variable bit rate (VBR) with a high degree of burstiness. In this research, we consider a network service that can provide deterministic or worst-case guarantees for delay-sensitive VBR video. A common belief is that such a service requires peak rate allocation and will necessarily result in low network utilization. This is not true!

In the first part of my talk, I will identify the factors that affect the achievable network utilization, and show the fundamental limits and tradeoffs in providing deterministic guarantees to VBR video. In the study, a set of 10 to 90 minute long MPEG-compressed video traces were used for the evaluation. Contrary to conventional wisdom, we are able to show that, in many cases, a deterministic service can be provided to video traffic while maintaining a reasonable level of network utilization.

In the second part of my talk, I will show that even higher network utilization can be achieved by allowing applications to dynamically renegotiate traffic parameters with the network. Such an approach has the added advantage that it provides a practical solution to the problem estimating traffic parameters for live video.