RED-VBR: a renegotiation-based approach to support delay-sensitive VBR video

Abstract.

Previous approaches to supporting video on packet-switched networks include deterministic service, statistical service, predicted service, and feedback-based schemes. These schemes represent different tradeoffs in quality of service (QOS), achievable network utilization, and method of dealing with overload. In this paper, we propose a new service called REnegotiated Deterministic Variable Bit Rate Service (RED-VBR) that attempts to strike an efficient balance with the above tradeoffs. The approach is based on deterministic guarantees with client-controlled renegotiation of traffic and QOS parameters and graceful adaptation during overload periods. We introduce a connection admission control algorithm for RED-VBR which bounds the renegotiation failure probability. We evaluate the scheme using two traces of MPEG-compressed video and show that, even with simple renegotiation polices and relatively low renegotiation frequencies, high network utilization in the range of 50–80% can be achieved. For traffic that is bursty over long intervals, this represents a 100–150% improvement in network utilization compared to deterministic service. Compared to statistical and predicted service, our approach allows more graceful and client-controlled QOS degradation during overload periods.