A Performance Model for ATM Switches with General Packet Length Distributions

The maximum throughput of an ATM switch is investigated in the presence of an offered load of multi-cell packets. For the case of input queueing coupled with a round robin policy for transferring cells from inputs to outputs, the system is approximated by a multi-class product form queueing network. Under the assumption that packet lengths are described by random variables with discrete Coxian distributions, it is shown that the balance equations describing the behavior of the ATM switch approach those for a multi-class product form queueing network and that the steady-state probabilities of such an ATM switch approach the product-form solution as the cell length tends to zero. Last, a numerical investigation shows that the approximation yields good results, even when the packet lengths are not well described by Coxian distributions. Supported in part by the National Science Foundation under grant NCR-9116183 0 1 Introduction The standard model for an ATM switch typically assumes ..