Multi criteria analysis of Controller Placement Problem in Software Defined Networks

Controller Placement Problem (CPP) is an important task in Software Defined Networks (SDNs). Meanwhile, the assignment of switches to the controllers plays a key role in the Quality of Service (QoS). Most of previous works assumed that each switch is assigned to the nearest controller based on propagation latency. In this paper, propagation delay, hop count and link utilization are considered for such assignment. First, the influence of these metrics on the QoS is analyzed. Then, using these criteria, a new Analytic Hierarchy Process (AHP) technique is presented to perform the multi criteria assignment process. Several evaluations are conducted to analyze this approach and justify the importance of trade-off among all the assignment criteria. Furthermore, an algorithm called Controller Placement Genetic Algorithm (CPGA) that is hybridized by the proposed AHP technique is introduced to solve this special kind of CPP. Results show the efficiency of our new assignment approach regarding link load balancing problem.