Software Defined Network


SDN is  an approach network architecture that decouples the control and data planes, making the network control plane (network intelligence and policy making) to a directly programmable application called a controller.

SDN encompasses multiple kinds of network technologies designed to make the network more flexible and agile to support  the virtualized server and storage infrastructure of the modern data center and Software defined networking was originally defined an approach to designing, building, and managing networks that separates the network’s control (brains) and forwarding (muscle) planes enabling the network control to become directly programmable and the underlying infrastructure to be abstracted for applications and network services.


SDN architectures generally have three components or groups of functionality.

  • Controller
    The “brains” of the network. It allows SDN users to gain a central look at the entire network, and empowers network administrators to instruct switches and routers how the forwarding plane should direct network traffic.
  • Southbound API
    SDN uses southbound APIs to relay information to the switches and routers “below.”
  • Northbound API
    SDN uses northbound APIs to communicates with the applications and business logic “above.” These help network administrators to programmatically shape traffic and deploy services.


Software Defined Network provides the following benefits:

  • Directly programmable. SDN environments can easily adjust to the rapidly changing needs of businesses. SDN can lower costs and limit wasteful provisioning, as well as provide flexibility and innovation for networks
  • Enable innovation. SDN enables organizations to create new types of applications, services, and business models that can offer new revenue streams and more value from the network
  • Reduce CapEX and OpEX.
  • Deliver Agility and Flexibility. Software Defined Networking helps organizations rapidly deploy new applications, services, and infrastructure to quickly meet changing business goals and objectives
  • Centralized Management.