Priority-based high-speed switch scheduling for ATM networks

In 1], the authors described the design of the AN2 switch which supports high-performance distributed computing. The switch's operation is based on the parallel iterative matching algorithm to nd a maximal matching between the inputs and the outputs of the switch. The number of iterations needed to nd a maximal matching in their algorithm is N in the worst case, and of time complexity O(log N) in the average case, where N is the size of the switch. In this paper, we propose an improved parallel iterative matching algorithm which uses the priority lists, instead of random-ness, to determine the input/output pairs that can be matched in each iteration. We show that the proposed algorithm does not suuer from the starvation problem, and needs at most dN=2e iterations to nd a maximal matching. We also show via probability analysis and simulation that the proposed algorithm outperforms the original one in the average case, especially when the switch size is large, e.g., for N 32. All these merits make it attractive to apply the algorithm to large switches used in ATM networks with high QoS requirements .