Fault-tolerant ATM switch using logical neighborhood network

A fault-tolerant ATM switch based on the logical neighborhood network is presented. The switch is targeted for terabit switching through localized traffic control and management, use of input/output queuing, distributed simple cell routing algorithm, and soft fault tolerance. The redundant hardware for fault tolerance is actively used by the switch to increase throughput, hardware utilization, and reduce cell loss and delay. For an N×N switch, the inherent structure of the LN-ATM network allows the simultaneous delivery of log₂ N+1 ATM cells to any output port. This is achieved using bit-serial operation and without speeding up the switching fabric. An attractive advantage of the proposed switch is support of data broadcast and hot-spot operation without the use of replicating hardware modules. We also propose a dynamic routing algorithm which detects blocked and/or faulty links. The switch throughput, cell loss probability, and performance under faults are studied using numerical simulation.