Leap forward virtual clock: a new fair queuing scheme with guaranteed delays and throughput fairness

Abstract

We describe an efficient fair queuing scheme, leap forward virtual clock, that provides end-to-end delay bounds similar to weighted fair queuing (WFQ), along with throughput fairness. Our scheme can be implemented with a worst-case time O(loglogN) per packet (inclusive of sorting costs), which improves upon all previously known schemes that guarantee delay and throughput fairness similar to WFQ. Interestingly, both the classical virtual clock and the self-clocked fair queuing schemes can be thought of as special cases of our scheme, by setting the leap forward parameter appropriately.