Networking as we know it is on the verge of a momentous change, thanks to a path breaking technological concept known as software defined networking (SDN).
SDN is the result of pioneering effort by Stanford University and University of California, Berkeley and represents a paradigm shift to the way networking elements operate. It is based on the OpenFlow Protocol.
Networks and network elements, of today, have been largely closed and have been based on proprietary architectures and operating systems. In today’s network and switching and routing of data packets happen in the same network elements, such as the router.
SDN decouples the routing and switching of the data flows and moves the control of the flow to a separate network element namely, the flow controller.
The motivation for this is that the flow of data packets through the network can be controlled in a programmatic manner.
A Flow Controller can be typically implemented in a standard PC. In some ways this is reminiscent of Intelligent Networks and Intelligent Network Protocol which delinked the service logic from the switching and moved it a network element known as the service control point.
The OpenFlow Protocol has 3 components to it. The flow controller that controls the flows, the OpenFlow switch and the flow table and a secure connection between the flow controller and the OpenFlow switch.