Patent attributes
A system and method are provided for cut-through packet routing in a packet communications switch fabric. The method comprises: accepting information packets addressed to a plurality of output port card egress ports at an input port card ingress port; routing information packets between port cards on backplane data links through an intervening crossbar; maintaining a credit counter for each port card egress destination, at the input port card; decrementing the counter in response to transmitting cells in a packet from the input port card; and, incrementing the counter in response to transmitting cells from the packet at the output port card. In some aspects of the method, accepting information includes buffering the packets in an ingress memory subsystem (iMS). Routing information includes the iMS transmitting buffered packets on a selected backplane data link. Decrementing the counter includes the iMS communicating with the iPQ in response to transmitting a cell.
