A New Approach to Support Delay-Sensitive VBR Video in Packet-Switched Networks

Previous approaches to supporting video on packet-switched networks include deterministic service, statistical service, predicted service , and feedback-based schemes. These schemes represent diierent trade-oos in quality of service (QOS), achievable network utilization, and method of dealing with overload. In this paper, we propose a new service that attempts to strike an eecient balance with the above tradeoos. The approach is based on deterministic guarantees with client controlled rene-gotiation of QOS parameters and graceful adaptation during overload periods. 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% to 80% can be achieved. For traac that is bursty over long intervals , this represents a 100% to 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 period.