Patent ID: 8331232

Claim:
A packet router fabric card comprising: a plurality of ingress port circuits receiving data packets for transmission through the fabric card; a plurality of egress port circuits receiving packets from the ingress port circuits; switching circuits through which the ingress port circuits and the egress port circuits connect; and a scheduling circuitry that schedules assignments for the switching circuits; wherein individual ones of the ingress port circuits organize incoming packets that are destined for a specific egress port circuit into serial data packet trains, with a train including a start-of-train (SOT) and an end-of-train (EOT) identifier, and the switching circuits, upon receiving an EOT identifier, automatically switch to a next ingress port assignment and look for a new SOT to begin transmitting a new packet train to an egress port, and wherein the ingress port circuits also track the packet train transmission to the switching circuits, and send an almost done flag (ADF) to the scheduling circuit before reaching the EOT identifier, enabling the scheduling circuit to schedule the switching circuit about to receive the EOT identifier, to look for a SOT identifier for a next packet train.