Advanced Micro Devices, Inc.
Forward Progress Mechanisms for a Communications Network having Multiple Nodes

Abstract:

A communication network includes: a plurality of nodes in a topology, with each node having an upstream and a downstream neighboring node in the topology; a separate unidirectional communication link coupled between each node and that node's downstream neighboring node; and a separate unidirectional control link coupled between each node and that node's upstream neighboring node. A controller in each node keeps a count of packets sent by that node via the corresponding unidirectional communication link. The controller uses the count of packets sent to determine whether a given packet is allowed to be sent from that node to the downstream neighboring node and, if so, whether a full rate or a throttled rate is to be used for sending the given packet. Based at least in part on the determining, the controller selectively sends the given packet to the downstream neighboring node.