An enhanced algorithm for fair traffic conditioning in differentiated services networks

Fair bandwidth sharing among traffic flows with different characteristics in Differentiated Services (Diffserv) networks is the focus of the current research. This paper examines and enhances an algorithm developed to enforce fairness among disparate TCP flows in the Assured Forwarding (AF) service in Diffserv. Equation Based Marking (EBM) [1] was introduced by K Shin et al to enforce fairness in AF by monitoring existent network conditions used in marking decisions. The estimation of packet losses by the algorithm is integral to marking. The loss rates of different connections were demonstrated to converge hence enforcing a fair marking regardless of the metrics of individual flows. In this paper, EBM is analyzed for fairness and enhanced by implementing a more efficient technique for loss rate estimation. Comparison is made between EBM and the enhanced technique with results showing appreciable improvements in the maintenance of fairness. Furthermore, a service definition required by QoS standards is met with the implementation of the additional algorithm to EBM.