Design and implementation of a closed loop time delay feedback control (CLTD-FC) system for mitigating DDos attacks

Abstract

Denial of Service (DoS) attacks can be used to disrupt the availability and performance of networked systems by bombarding targeted hosts with malicious traffic thus hampering their capabilities, or worse exhausting them. In this paper, by utilizing a mathematical model that reflects the dominant features of DDoS attacks we will introduce how to explore an approach in countering its effects. We propose a closed loop time delay feedback control (CLTD-FC) system by designing an appropriate feedback controller. This infrastructure is in turn exploited to design a control theoretic mitigation strategy that effectively dampens the queue dynamics of internet routers during DDoS scenarios. Specifically, we demonstrate that the CLTD-FC scheme appropriately maintains and monitors queue stability whilst simultaneously enabling convergence to desired operational targets under continual attacks. The method is implemented in the network simulator platform NS2 to validate its proposed effectiveness. Simulation results show that the proposed CLTD-FC scheme can help to improve QoS, ensure network fairness as well as stabilize and optimize queue performance compared with Drop-tail solution.