Hundreds of research initiatives worldwide are redesigning the Internet. Many of them are adopting the software-defined networking (SDN). What does it means? How do you define it?
SDN decouples the control and the data planes and centralizes the control plane operations. Currently, most work in this domain is concentrated on the layer-2 and layer-3 functionalities. Higher layers can benefit from the global network view provided by SDN.
SDN is a network architecture.SDN centralizes the intelligence and distributes the action over the packets. The classical architecture distributes intelligence and actions.
Software Defined Networking is more that just control/data plane separation (ask people working in optical networks) or centralized control. SDN is more about providing network developers with high level interface and abstractions for controlling their networks.
It is a framework to solve a set of problems Many solutions
Software-Defined Networking (SDN) has been envisioned as a way to reduce the complexity of network configuration and management, enabling innovation in production networks.
SDN is allow network administrators to automatically and dynamically manage and control a large number of network devices, services, topology,traffic paths, and packet handling(quality of service)policies using high-level languages and APIs.