Patent attributes
Flow control in a distributed switch fabric (100, 200) includes detecting at least one of a congestion condition (238) in a downstream transceiver port (205) and an oversubscribing condition (257) of a channel buffer (230), where the downstream transceiver port (205) and the channel buffer (230) both correspond to a channel (231) of a traffic manager (208). Packets begin accumulating in the channel buffer (230). Per-flow flow control (254) operates to modify transmission of the packets over the channel (231) to the channel buffer (230) if the channel buffer (230) reaches a threshold value (256). Link level flow control (252) operates transparently to the traffic manager (208) if the congestion condition (238) is detected and the channel buffer (230) fails to reach the threshold value (256).