Patent ID: 7180862

Claim:
A method performed in a switch for controlling congestion, the switch disposed on a board coupled with a backplane, wherein at least a separate source board and a separate destination board are also coupled with the backplane, the method comprising: determining a queue occupancy of a virtual queue associated with an input port of the switch and with an output port of the switch, the input port communicatively coupled with the source board and the output port communicatively coupled with the destination board, the source board providing data to the switch for transmission to the destination board; and sending a message from the switch to the source board if the queue occupancy of the virtual queue reaches a threshold occupancy, the message to direct the source board to alter a transmission rate to the destination board, wherein the threshold occupancy comprises a specified quantity of data, a specified number of packets, or a specified number of packet addresses; wherein transmission rates from the source board to a number of other boards coupled with the backplane are unaltered by the message.