A Computation Method for Providing Statistical Performance Guarantee to an ATM Switch1

ATM is a connection-oriented technology and messages are divided into fixed size packet called cells to facilitate communications. However, before two hosts can communicate, a connection has to be established between them. Consider a real-time communication application running on top of an ATM network. In order to provide the real-time service, we require the network to provide a performance guarantee for the connection. There are two types of performance guarantees: deterministic and statistical guarantees. While a deterministic guarantee provides an absolute bound on the worst case cell delay experienced in an ATM switch, a statistical guarantee provides a probabilistic bound on the worst case cell delay. In this paper, we use a self-similar stochastic process to characterize the arrival of the real-time traffic. Extending from our previous work on deterministic delay guarantee, we provide methods for determinating the statistical delay bound for the worst case cell delay in an ATM switch with various output port controllers. We conclude this paper with two case studies: one based on ordinary LAN traffic and one on the variable bit-rate MPEG video transmission of the movie Star Wars. To show the effectiveness of our statistical delay guarantee, we compare it with the delay derived by Cruz as well as the actual cell delay determined by the two traffic traces.