BMSN and SpiderNet as large scale ATM switch interconnection architectures

In this paper, we propose the use of the Bidirectional Manhattan Street Network (BMSN) for interconnecting fixed size switching modules into a large scale ATM switch. Using BMSN for this purpose, each node now becomes an ATM switching module with its own input and output ports, and with four extension trunks connecting to four neighbouring modules. In this way, the switch size and capacity can increase by adding switching modules in a stepwise and planar manner, and there is no need of rewiring the I/O ports and the internal links. We extend BMSN into another architecture called SpiderNet, which connects eight instead of four neighbours. The average path length is reduced by having more direct paths. SpiderNet gives a better call blocking performance and cell loss probability, hence has a higher switch capacity. We show how routing paths can be established, and how cells are self-routed through the interconnected fabric. Cell loss and delay performance will also be discussed.