Equation-based packet marking for Assured Forwarding services

This paper introduces a new packet marking algorithm that can be used in the context of Assured Forwarding (AF) in the Differentiated Services (DiffServ) framework. The new marking algorithm is called equation-based marking (EBM) and is based on the TCP model in Padhye et al. (1998). EBM is to handle the problems found in other marking schemes regarding fairness among heterogeneous TCP flows through a tight feedback-loop operation and adaptation of the packet marking probability to network conditions. We design a packet marker that uses EBM as the marking algorithm, and evaluate its performance using in-depth simulation. We also prove analytically the correctness of the marking algorithm and compare it with other marking schemes for different network scenarios. Our evaluation results demonstrate the effectiveness of EBM in providing the required fairness among heterogeneous flows and ensuring protection against nonassured traffic.