Fault tolerance in Clos-Knockout multicast ATM switch

In this paper, we propose a new architecture for multicast ATM switches with fault tolerant capability based on the Clos-Knockout switch. In the new architecture, each stage has one more redundant switch module. If one switch module is faulty, the redundant module would replace the faulty one. On the other hand, under the fault-free condition, the redundant modules in the second and third stages will provide additional alternative internal paths, and hence improve the performance. The performance analysis shows that the cell loss probability is lower than the original architecture when all modules are fault free, and the reliability of the original architecture is improved.