Packet latency based arbitration technique for a packet switch

Abstract

A packet switch including input ports having various input bandwidths initializes credit values for the input ports. An arbiter of the packet switch selects input ports based on the credit values and routes data packets from the selected input ports to a switch fabric of the packet switch. The switch fabric routes data packets from the selected input ports to output ports of the packet switch. Moreover, the arbiter modifies the credit value of each selected input port based on the latency for routing the data packet from the selected input port to the switch fabric. In this way, the arbiter promotes fairness in routing additional data packets through the packet switch. In some embodiments, the switch fabric includes a buffered crossbar and the arbiter modifies credit values of crosspoints in the buffered crossbar based on the latency for routing data packets from the crosspoints to the output ports.