New ATM switch design using wrapped around multiple (WAM) banyan network

Abstract

A new ATM switch called wrapped around multiple (WAM) banyan network is proposed in this paper. A WAM banyan switch is constructed using 2d × 2d switch elements. It consists of K parallel banyan switch planes and a packet is allowed to switch/overflow from one switch plane to another when packet contention occurs. This degree of freedom is provided by connecting the d logically equivalent output links from a switch element to d logically equivalent switch elements in the next stage, one in each plane. To further enhance the performance of this switch design, packet broadcasting is used together with priority switching. It is found that under full loading, a WAM banyan switch with K = R = d = 3 can have a packet loss probability Ploss ≤ 10-6 for a switch with size up to 4096 × 4096. Changing the loading from λ = 1.0 to 0.8 can give about one order of magnitude further improvement in Ploss.