An efficient admission criterion of traffic-shaped rate monotonic scheduler for VBR traffic

Abstract

The rate monotonic algorithm has recently been proposed to be used along with traffic shapers to provide quality of service guarantees in ATM networks. A necessary and sufficient condition for admission control has been derived assuming that cell arrivals are periodic (i.e., CBR traffic). For bursty traffic, this criterion is obviously conservative and may significantly reduce bandwidth utilization. In this paper, we present an efficient admission criterion for bursty or VBR sources. We assume that the traffic generated by a VBR source is regulated with a token bucket regulator. Our admission criterion takes into consideration traffic characteristics. Since traffic characteristics change from hop to hop, every network node is required to know how many hops a connection has traversed. Numerical results show that, compared with the conservative criterion which assumes periodic cell arrivals, system utilization can be largely improved using our admission criterion.