A Credit-based Active Queue Management (AQM) Mechanism to Achieve Fairness in the Internet

Abstract. Router-based algorithms to address the TCP-friendliness problem have focused on providing fairness to TCP connections by penalizing UDP unresponsive flows. As a result, current schemes have overlooked their effect on streaming applications. In addition, current schemes have not been widely implemented in practice because of their high complexity and their inability to provide fairness when multiple unresponsive flows, packets of different sizes, and bursty traffic are present. All these aspects and scenarios, commonly found in practice, are rarely addressed in the literature. In this paper, we present Achieving Fairness using a Credit-based mechanism or AFC, a simple Fair Active Queue Management (FAQM) mechanism that aims to solve the unfairness problems generated under these realistic conditions. Simulation results show that AFC provides smoother transfer rates for unresponsive flows transmitting real-time traffic, handles multiple heavy unresponsive flows better, improves the fairness among TCP connections with different round-trip delays, and achieves good fairness even under bursty traffic and packets of different sizes