A close-form performance approximation for nonblocking ATM switches with channel grouping

We study the performance of an ATM switch which clusters a set of broadband packet channels as a transmission group. The exact analysis for the performance of systems employing this concept includes solving for the roots of equations involving transcendental functions and can only be carried out numerically. Thus, its performance has mainly been understood by the use of simulation. We derive a close-form approximation for the performance of multichannel switches under independent uniform input traffic. Our approximation differs from simulation results by at most 8 percent for channel group sizes r=2,...,32 and is exact in the case where the channel group size is unity