Performance study of an input queueing ATM switch with windowing scheme for IP switching system

In this paper, we investigate the performance of a nonblocking input queueing asynchronous transfer mode (ATM) switch with windowing scheme for IP switching system. In particular, this paper analyzes the effects of nonuniform and correlated bursty traffic on the performance of the input queueing switch with windowing scheme. We consider four specific traffic patterns: uncorrelated non-bursty, correlated bursty, uniform and nonuniform traffic. Under the uncorrelated non-bursty traffic, we obtain the maximum throughput as a closed-form solution, and the analytic results are verified by simulation. On the other hand, under correlated bursty traffic, we obtain the maximum throughput through simulation. From the results, we know that the windowing scheme can reduce the head-of-line (HOL) blocking at the input ports and increase the maximum throughput up to 1 under uncorrelated and uniform traffic. However, the windowing scheme can not provide the performance improvement of the input queueing switch because of the congested output blocking under correlated bursty and/or nonuniform traffic. So, the designer should take into account the windowing scheme combined with a separate logical output queue for each output port and traffic load balancing or randomization techniques to build IP switching systems.