Connection Admission Control for RED - VBR , a

In 16], we proposed a new service called REnegotiated Deterministic Variable Bit Rate Service (RED-VBR). RED-VBR attempts to strike an eecient balance among tradeoos in quality of service, achievable network utilization, and method of dealing with overload situations. The approach is based on deterministic guarantees with client controlled renegotiation of traac and QOS parameters and graceful adaptation during overload periods. In this paper, we introduce a new 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% 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 a statistical service, our approach allows more graceful and client-controlled QOS degradation during overload period.