Module matching schemes for input-queued Clos-network packet switches

Current schemes for configuration of input-queued three-stage Clos-network (IQC) switches involve port matching and path routing assignment, in that order. The implementation of a scheduler capable of matching thousands of ports in largesize switches is complex. To decrease the scheduler complexity for such switches (e.g., 1024 ports or more), we propose a configuration scheme for IQC switches that hierarchizes the matching process. In a practical scenario our scheme performs routing first and port matching thereafter. This approach reduces the scheduler size and the configuration complexity of IQC switches. We show that the switching performance of the proposed approach using weight-based and weightless selection schemes is high under uniform and nonuniform traffic.