Deficit Round Robin with Network Calculus

Generalised Processor Sharing (GPS) is a well-known ideal service policy designed to share the capacity of a server among the input flows fairly: each backlogged flow receives a pre-defined fraction of the total server capacity, according to its weight. Several practical implementations of GPS have been proposed, among which Deficit Round Robin (DRR) is widely deployed since it can be implemented in a very efficient way. The worst-case performance of DRR has been studied by several papers, all of which assume that the shared server has a constant rate. This paper studies DRR using Network Calculus, under very general assumptions. Latency results that generalise all the previous works are derived, and a residual service is derived from DRR parameters. This residual service is shown to be as good as or even better than previous studies when restricting it to the same assumptions.