Directional and priority based flow control mechanism between nodes

A node, comprising:

• a two dimensional array of transmit queues to store frames to be transmitted from the node to another node, a size of the array governed by a number of directions, N, to which the other node may forward one or more of the frames, once received, and a number of priorities, M, one of which may be associated with each of the frames to be transmitted, the transmit queues distinguished from each other based on direction and priority;
• a transmitter coupled to the transmit queues to transmit frames dequeued from the transmit queues to the other node;
• and
• control logic coupled to the transmit queues, the control logic to receive an indication from the other node whether the other node is experiencing traffic congestion in one or more of the N directions and a priority of frames at or below which the control logic is to control dequeuing of frames from the transmit queues corresponding to the one or more of the N directions in which the other node is experiencing traffic congestion.

A system comprising:

• a destination component comprising:
• a receiver to be coupled to a communication medium to receive frames of data therefrom;
• a demultiplexor to forward frames to be received in one or more of a plurality of directions;
• and
• a feedback logic block to generate an indication of traffic congestion in zero or more of the plurality of directions and a priority of frames at or below which to control a rate at which the receiver to receive frames to be forwarded to a congested direction;
• a source component comprising:
• a transmitter to be coupled to the communication medium to transmit frames to the receiver;
• a two-dimensional array of transmit queues coupled to the transmitter, one dimension defined by different priorities capable of being associated with the frames, the other dimension defined by different directions to which the demultiplexor can forward the frames, once received;
• and
• a control logic block having an input to receive the indication of traffic congestion in zero or more directions and the priority of frames at or below which to control a rate at which the transmitter to transmit frames to be forwarded by the demultiplexor to a congested direction, the control logic block having a separate output coupled to each set of transmit queues defined by the different priorities for a particular direction, over which to signal the rate at which frames to be forwarded to a congested direction and having a priority at or below that indicated are dequeued for transmission.