SWITCH POINT HAVING LOOK-AHEAD BYPASS

摘要

A network having a plurality of switch points, each switch point having both a main multi-stage pipeline and a look-ahead pipeline between input ports and output ports of the plurality of switch points is described. The look-ahead pipeline has fewer pipeline stages than the main multi-stage pipeline. Look-ahead information and corresponding packet are received at an input port. A first stage look-ahead request is generated from the look-ahead information. A second stage look-ahead request is generated in response to the first stage look-ahead request being not granted. And in response to the second stage look-ahead request being granted, transmitting a packet through the switch point using the look-ahead pipeline.

主权项

1. In a network having a plurality of switch points, each switch point having a plurality of ports for transmitting packets from a source device to a destination device, and each switch point having both a main multi-stage pipeline between ports of the plurality of ports and a look-ahead pipeline between the ports of the plurality of ports, wherein the look-ahead pipeline has fewer pipeline stages than the main multi-stage pipeline, a method comprising:
receiving a packet and look-ahead information corresponding to the packet at a port of a switch point; generating a first stage look-ahead request from the look-ahead information; determining that the first stage look-ahead request is not granted; generating a second stage look-ahead request from the first stage look-ahead request in response to the first stage look-ahead request not being granted; determining that the second stage look-ahead request is granted; and in response to the second stage look-ahead request being granted, transmitting the packet through the switch point using the look-ahead pipeline.