Cost calculation in load balancing switch protocols

摘要

A method for computing cost information associated with a port of a switch in a network of switches. Cost information is computed as a port load factor: a ratio of port latency over available throughput. Port latency is determined as the depth of a queue associated with the port divided by the speed of the port. Available throughput is determined as the speed of the slowest port on a given path associated with the port in question. Preferably, the queue depth is measured in bits and the port speed and available throughput are measured in bits per second. Further, in the preferred embodiment, port latency is computed as a weighted average as ((15xprevious latency)+current latency)/16. A higher value for the port load factor indicates a port which is more heavily loaded. The load factor is therefore useful in load balancing among the ports of switches and paths associated therewith.