Controller load balancing schemes in software defined networks

Software-defined networking (SDN) has been proposed as a new networking paradigm which separates the control and data forwarding planes. The controllers which are 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 is a challenging research question. Although various load-balancing schemes are proposed in the literature, this research topic is yet to be explored adequately. In this thesis, we discuss load-balancing issues in SDN and propose a load-balancing scheme, namely Cooperative Load Balancing Scheme For Hierarchical SDN Controllers (COLBAS). Moreover, we evaluate the performance of this scheme and investigate important trade-offs.