Cooperative load balancing for hierarchical SDN controllers

Software-defined networking (SDN) has been proposed as a new networking paradigm which separates the control and data forwarding planes. The controllers deployed as centralized network control entities are crucial for meeting the performance and efficiency requirements of these systems. The placement of these network entities, switch assignment and their load-aware operation are challenging research questions. Although various load-balancing schemes are proposed in the literature, this research topic is yet to be explored adequately. In this work, we discuss load-balancing issues in SDN and propose a load-balancing scheme, namely Cooperative Load Balancing Scheme For Hierarchical SDN Controllers (COLBAS), for hierarchical controller configurations. Moreover, we evaluate the performance of our scheme and investigate important performance factors.