DiffServ with Stochastic Weighted Fair Queueing and different buffer management schemes

N. Hegde and K. Avrachenkov


We compare policies that offer differentiated services to TCP traffic, with the goal of providing some sort of performance guarantees to a premium class of traffic. We consider TCP connections that have been classified into separate classes and study the effectiveness of a scheduling policy combined with various buffer management policies on the performance of these competing TCP connections. We use a stochastic model for a class-based weighted-fair-queueing scheduling policy where packets of different classes are scheduled according to their pre-assigned static weight. We consider two buffer management policies : complete partitioning, and complete sharing with pushout at various thresholds. We consider two classes of TCP traffic in our results. Our goal is to propose mechanisms with easily adjustable parameters to achieve service differentiation as required. In the numerical results we show how the scheduling and buffer policies can be used to provide some sort of performance guarantee to the higher class.