Patent ID: 8331387

Claim:
An apparatus comprising: a plurality of data egress modules; a data-switch fabric operationally coupled with the plurality of data egress modules; and a plurality of data ingress modules operationally coupled with the data-switch fabric, each of the plurality of data ingress modules comprising a set of virtual output queues, each set of virtual output queues comprising: a set of unicast virtual output queues including a respective unicast virtual output queue corresponding with each of the plurality of data egress modules; and a multicast virtual output queue, wherein the data-switch fabric is configured to: determine a change in a congestion state for one or more fabric egress queues included in the data-switch fabric; and send a flow control message to a given data ingress module corresponding with the change in congestion state, the flow control message including an indication whether data in at least one of the unicast virtual output queues of the given data ingress module or data in the multicast virtual output queue of the given data ingress module is associated with the change in congestion state, and wherein the data ingress modules are configured to receive and route data traffic to the respective data egress modules via the virtual output queues and the data-switch fabric in accordance with the flow control message.