OpenFlow decouples the control and data (packet forwarding) planes, and delegate the control functionality to a
logically centralized controller [11,12]. This separation significantly simplifies modifications to the network control
logic (as it is centralized). In particular, OpenFlow has succeeded in attracting commercial vendors. Amin T. et.al. [13]
presented the design and implementation of HyperFlow, a distributed event-based control plane for OpenFlow, which
allows network operators deploy any number of controllers in their networks.