Patent ID: 8213421

Claim:
A system for switching or routing data packets, the system comprising: one or more ingress line cards having one or more input ports; one or more egress line cards having one or more output ports; a switch fabric; and one or more control units comprising control units at the ingress line cards and control units at the egress line cards, wherein the control units at the one or more ingress line cards, segment a multicast packet into one or more fabric data units (FDU) prior to sending across the switch fabric, switch or route the segmented, multicast data packet from an input port to an output port across the switch fabric in two or more separate stages of packet replication, in a first stage, create one or more first replicas of the multicast data packet received from one of the input ports by one of the ingress line cards, and send each first replica across the switch fabric from a receiving ingress line card to the one or more egress line cards, wherein destinations of the multicast data packet are reachable in the first stage, and wherein at most one replica among the one or more first replicas is sent to any one egress line card among the one or more egress line cards, and the control units at the one or more egress line cards reassemble the multicast packet from FDUs received after being sent across the switch fabric, wherein a given egress line card among the egress line cards may indicate that it is unavailable to receive FDUs, and wherein the control units at the ingress line cards do not send an FDU to the given egress line card if the given egress card has indicated that it is unavailable to receive FDUs.