Software-defined networkingis a new approach to networking that brings programmability to network devices which is hitherto unseen in this field. It also enables centralized managing of network devices. It enables programming devices in plethora of languages like Java,Python,Ruby,C,C++.It also promotes open software in networking devices rather than closed source systems which exist today.

Current network scenario is marred by many problems like complexity which is caused by plethora of protocols developed by organisations which are static in nature in contrast to dynamic nature of traffic. Current networks cannot be managed through centralised systems.They are unscalable in nature which make them unsuitable to ever increasing requirements of networks. Also today’s networking industry is a oligarchy consisting of few companies.

We need a new network architecture due to various reasons like constantly changing traffic patterns. IT industry’s rapid embracement of cloud services has created security & complexity problems which need to be addressed. Handling today’s big data means exponential increase in required bandwidth which is hard to satiate. All this problems can be answered using software defined networking (SDN).

SDN is characterised centralised control of multi vendor devices. All SDN enabled network devices can be controlled by a centralised system irrespective of the vendor. OpenFlow-based SDN offers a flexible network automation and management framework, which makes it possible to develop tools that automate many management tasks that are done manually today. OpenFlow‘s flow-based controlmodel allows IT to apply policies at a very granular level, including the session, user, device, and application levels. Main feature of SDN is that it brings awesomeness of open source to networking & thus automatically bringing down the cost of networking devices.