A Survey of Load Balancing Approaches Based on Switch Migration in Software-Defined Networks

Abstract

Large scale software-defined networks have two main concerns, which are scalability and reliability. One of the problems with multi-controller architectures in these networks is the static mapping between SDN switches and controllers, which prevents the control plane from adapting to traffic changes. The dynamic mapping between switches and controllers by migrating switches from highly loaded controllers to lightly loaded controllers can provide compatibility for the control plane. This paper first discusses multi-controller load balancing as a key research challenge and then explores switch migration as a solution. A variety of load balancing methods based on switch migration are investigated and then a comprehensive comparison is made between them.