On SDN controller placement to achieve robustness against targeted attacks

Abstract

The software defined network (SDN) is an emerging technology that promises to simplify network management. SDN networks require one or multiple controllers to manage a set of SDN switches. Determining the locations of SDN controllers is known as the controller placement problem. Selection algorithms such as k-median and k-center have been proposed to select k controllers for the sole purpose of minimizing end-to-end delays. In this paper, we propose a greedy selection algorithm to determine the locations of k controllers to improve overall network resilience against targeted attacks. Our algorithm uses robustness functions, namely, algebraic connectivity (AC) and network criticality (NC), while determining controller locations to improve network robustness. For evaluation, we apply our selection algorithm to three backbone networks and study their network resilience against targeted attacks. Our results indicate that our selection algorithm, with the purpose of minimizing NC, yields better network resilience than the k-median and k-center methods against such attacks.