Quasi-output queue behavior of a packet switching device achieved using virtual output queue ordering independently determined for each output queue

Abstract

In one embodiment, quasi-Output Queue behavior of a packet switching device is achieved using virtual output queue (VOQ) ordering independently determined for each particular output queue (OQ), including using maintained latency information of the VOQs of the particular OQ. In one embodiment, all packets from all VOQs with a same port-priority destination experience similar latency within specific time-window, which is similar to the packet service provided by an Output Queue switch architecture. In one embodiment, all input ports that send traffic to same output port-priority receive bandwidth which is proportional to their bandwidth demand divided by total bandwidth. Prior approaches that emulate the performance of an OQ switch architecture require complex and time-consuming scheduling determinations and do not scale. Independently determining the order for sending packets from the VOQs associated with each particular OQ provides a scalable and implementable system with quasi-Output Queue behavior.