Hardware implementation of windowing in a multicast packet switch

In a banyan based broadband packet switch using input queuing, the throughput of the switch is limited by the head of line blocking. Head of line blocking prevents packet in the input buffer from accessing an available output port in the network since the packet ahead of it in the buffer is blocked. Windowing is a technique used to mitigate the head of line blocking by relaxing the strict first-in-first-out queuing discipline of the input buffers. In this paper, we present a hardware implementation of windowing for a multicast packet switch. This implementation is further extended to include cyclic priority discipline to insure fairness among the input ports.