A fault-tolerant switching network for B-ISDN

The author proposes a self-routing fault-tolerant switching network for asynchronous transfer mode (ATM) switching systems. The network has many subswitches to enhance the fault tolerance of the conventional multistage interconnection network which only has a unique path. The subswitches provide large numbers of alternative paths between switching stages and allow the network to tolerate multiple paths. The routing algorithm is quite simple. The paths can also be used to route cells under the condition that internal cell contentions occur in switching elements. A reliability analysis shows a quantitative measurement of the improvement in fault tolerance as compared with previously presented fault-tolerant networks. A performance analysis and simulation results show that the proposed network has a high level of maximum throughput. In addition, that level of throughput is maintained with reasonable cell delay even though the number of faulty components increases in the network