I-DWRR — An insolvency enabled scheduling scheme extending Deficit Weighted Round Robin

The allocation of network resources to flows within a computer network is performed using scheduling algorithms with the aim of enabling every flow to receive the required resources to perform well. One of several algorithms proposed in the last decades is the well-known Deficit (Weighted) Round Robin (D(W)RR) scheduling algorithm proposed by Shreedhar and Varghese. It has a low complexity, but at the same time allows fair and weighted sharing of limited resources. Nevertheless, DWRR does not work deadline compliant and active handling of nearly over-delayed packets is not considered. In this paper, we present a novel insolvency enabled extension of the DWRR scheduling algorithm called I-DWRR. It reduces the number of deadline violations by preventing them using an innovative mechanism called Queue Insolvency (QI). The proposed extension provides a lower packet-loss rate for multi-queue scenarios in comparison to DWRR while keeping the occurring latency equal to DWRR. The algorithm and its benefits have been validated through a broad simulation study.