On the performance of the proportional delay differentiation

While DiffServ is gaining ground, QoS related operations have been constantly changing. The proportional differentiation model, as a special case of DiffServ, was suggested to enforce controllable and consistent QoS differentiation. The article investigates the delay differentiation perspective of the proportional model. It first derives the properties of the average delay differences among service classes. Second, simulations and analysis are applied to reveal more fundamental facts of two typical delay differentiation mechanisms. Last, their short-term and long-term delay differentiation performances are evaluated.