On the load balanced controller placement problem in Software defined networks

In Software defined networks (SDNs), controller placement is an important problem which will affect the performance of the network directly. At present, there have been some studies on the controller placement problem in SDN from different aspects such as delay, capacity, reliability and load balance. In this paper, the controller placement problem is discussed from the aspect of delay and load balance at the same time. More precisely, for a given topology, we study how to choose locations of the multiple controllers to minimize the average delay or the worst delay of all control paths under the consideration of load balance. The trade-off between delay and load balance is investigated through simulation. The results show that the load of the control plane can be well balanced with only a little increment of the objective delay.