A Study on Multi-Controller Placement Problem (MCPP) in Software-Defined Networks

In the present scenario, Internet usage has drastically increased and new technologies are getting evolved, traditional networking is not suitable as it faces network management issues. The software-defined network (SDN) provides a more adaptable and flexible topology by cleaving the control plane and the data plane to centralize the network through a software unit called a controller. Researchers have found that controller placement significantly affects the performance of the SDN. Initially, a single controller is used but this is only suitable for small-range networks single point failures and scalability issues are raised. To solve the problems in the single controller, the concept of multi-controller was introduced, which compresses the issue of single-point failure. Now placing these controllers place a vital role in network performance. A comprehensive study on the multi-controller placement problem (MCPP) in SDN in the aspects of load balancing, reliability, optimization, and dynamic placement techniques is carried out. A classification of these techniques is done along with their usage so that the researchers can go through it and may understand the working principle easily.