Distributed Hierarchical Control Plane of Software Defined Networking

Single controller implementation of SDN has many problems related to single points of failure, computational complexity growth, reliability and scalability. To solve these problems, multi-controller implementation of Software Defined Network has been introduced. Multiple controller implementation of the SDN control plane for large networks environment solves the scalability and reliability issues introduced by the centralized controller of the SDN. However, there are still open research topics related to controllers placement. Work has been done in placement of controllers and making solution to earlier problem like single point of failure and computational complexity growth. Distributed hierarchical control plane architecture of SDN using multiple controllers of large-scale networks is presented. Simulation result shows that hierarchical architecture solved many problems those were arising earlier in single controller architecture. Distributed hierarchical architecture does not have single point failure problems. Proposed architecture effectively reduces the computational complexity growth of SDN control plane from super-linear to linear.