Performance analysis of shared buffer ATM switch with different cell departure models

The performance analysis of an asynchronous transfer mode (ATM) switch involves modeling the input traffic source, the switching mechanism, and the cell departure process. A main issue which determines the overall accuracy in performance evaluation of ATM switch, is the use of an appropriate probabilistic model to describe the cell departure process. Until now, little work has been done in the literature on characterizing the cell departure process for studying the performance of an ATM switch. This paper compares and verifies the accuracy of several models, including a new one called the "Urn model", which we propose. These models are put under test in a performance evaluation of a shared buffer ATM switch, by using a discrete-time Markov chain. The numerical results are compared to the simulation, and they show that the Urn model is a good compromise between accuracy and efficiency. This finding is significant because it helps to speed up the running of an analytical model of a large network while providing satisfactory accuracy.