PERFORMANCE STUDY OF A SELF ROUTING CYCLIC BANYAN NETWORK

Abstract

Multistage switching networks have been widely used as efficient interconnection structures for parallel computer systems and the switching nodes in high-speed communication networks. The multistage switching network is built up of smaller switch elements (SE's) which are connected, through their links, to other SE's or terminal devices. The multistage switching networks are expected to be used in broadband integrated services digital networks (B-ISDN's) and transport systems based on ATM. Because the Internet data traffic that will be majority of the traffic in B-ISDN is bursty, there is a higher possibility that there are multiple cells arriving simultaneously at an SE through different incoming links that may have to be forwarded along the same outgoing link. To deal with such link contention problem, Banyan network is modified by augmenting extra internal links. This switching network is called cyclic Banyan network, of which the fully adaptive self-routing scheme exploits all links of SE's as alternate links/paths. To utilize all the links of the network as alternate paths, cells failing to get selected for the intended link are sent along different links, in the hope that they later return, or detour the contended link and continue their journey to the destination. Cells are never dropped within the switching network, whereas the switch has no multiple cell buffers.