Internal cut-through for distributed switches

摘要

Processing techniques in a network switch help reduce latency in the delivery of data packets to a recipient. The processing techniques include internal cut-through. The internal cut-through may bypass input port buffers by directly forwarding packet data that has been received to an output port. At the output port, the packet data is buffered for processing and communication out of the switch.

主权项

1. A method comprising:
beginning to receive a packet at an input port; determining an output port for the packet; determining existence of buffered data destined for the output port at an input buffer associated with the input port, the input buffer being separate from an output buffer associated with the output port: buffering packet data from the packet at the input buffer instead of forwarding the packet data to the output port in response to the input buffer containing buffered data destined for the output port; and forwarding the packet data from the packet to the output port without buffering the packet data at the input buffer in response to receiving an eligibility status message from the output port, wherein the eligibility status message conveys that the output port does not have enough buffered data to absorb a control loop delay without an interruption of communication out of the output port, and the control loop delay comprises time taken to send a data credit message from the output port to the input port.