CWT: an efficient queue urgency metric with application to high-speed packet switching

Determining queue urgency (or weight) is a fundamental challenge, particularly in the context of high-speed packet switching. Weighting schemes have significant impact on the decisions made by arbitration and/or scheduling mechanism, thus directly shaping the overall performance of the system. Various weight functions, including iterative longest-queue-first (iLQF) and iterative oldest-cell-first (iOCF) have been presented in the literature. However, existing schemes suffer from limited performance in the presence of non-ideal traffic patterns. In this paper, we introduce the cumulative waiting-time (CWT) queue-weighting scheme, which is a pragmatic mechanism for dynamically determining the queue weight based on its aggregated cells waiting time.