The maximum throughput of a single-stage non-blocking input-queued switch such as the sort-banyan network is shown to be 0.586 under the uniform traffic model. It can be increased to 0.88 or 0.97 respectively if the switch is speeded up by a factor of 2 or 3. Hui and Lee (1992) showed that, for a large scale three-stage switch built with sort-banyan switch modules, the maximum throughput reduces to 0.458. The analysis was performed based on the assumption that the number of middle-stage switch modules is equal to the number of input/output links of a switch module. In the paper, the authors study the effect of increasing the number of middle-stage switch modules and speeding up the switch. Numerical results are obtained and verified by computer simulations for various combinations. For example, with a speedup factor of 2, the maximum throughput can be improved to 0.85 if the number of middle-stage switch modules is doubled.>

A fair high-speed copy network for multicast packet switching is described. The authors modify the architecture of the copy network proposed by T.T. Lee (1988) to make it fair to all the inlets, and reduce the clock rate requirement of the switching fabric. Fairness is achieved by adding a banyan network to perform cyclic shifts in front of the copy network. A pipelined architecture is proposed to avoid a huge internal speed-up. The clock rate requirement of the proposed copy network is evaluated and compared with that of the original design. It is found that the clock rate requirement can be reduced significantly if the number of inlets is larger than 64.>