Multi-Controller Placement for Load Balancing in SDWAN

The capability of flexible network management makes it available to incorporate software-defined networking (SDN) in the wide area network (WAN). Thereinto, multiple controllers are deployed in the software-defined wide area network (SDWAN) to tackle the performance bottleneck. Thus, how to effectively solve the load balancing problem in the control plane towards SDWAN under different constraints isworthy of further study. In order to achieve load balancing among the distributed controllers, we proposed a low-complexity controller placement algorithm, Simulated Annealing Partition-based K-Means (SAPKM), towards SDWAN. Meanwhile, two cost functions were proposed as the load balancing indices to assess the efficiency of the proposed algorithm from the perspective of topology structure and flow traffic distribution, respectively. Simulations were performed by using actual topologies on Topology Zoo with different sizes and different structures. Experimental results demonstrated the effectiveness of SAPKM in reducing both average load and load balancing indices with propagation latency and network reliability performance enhanced simultaneously.