OpenFlow/ Software Defined Networking (SDN) - What & Why ?

OpenFlow/SDN is emerging as one of the most promising and disruptive networking technologies of recent years. It has the potential to enable network innovation and create choice, and thus help realize new capabilities and address persistent problems with networking. It also promises to give network operators more control of their infrastructure, allowing customization and optimization, therefore reducing overall capital and operational costs. 

In short, Software Defined Network will enable virtalization for your networking and networks in near future would be used just as we do it with server virtualization. 

But how would this happen ?

Each hardware device (switch, router, server, or firewall) operates as its own isolated island which requires individual configuration. Seeing the shortcomings of such a setup, researchers and startup companies like Nicira have started to develop open software control systems under a coined term of “software defined networking” (SDN). Stuart Miniman defines SDN as “a model for network control, based on the idea that network traffic flow can be made programmable at scale, thus enabling new dynamic models for traffic management.” Similar to the way virtualization can be used to host many (virtual) computers on one physical piece of hardware, these virtualized networks could allow companies to run multiple network slices off of a single physical network.

This is a level of control and programmability that is not currently possible due to network hardware vendors using proprietary software in all their devices (Cisco’s IOS for example). SDN takes the proprietary code out of the equation, and — using open software on all the routers, switches, firewalls, and other network devices — separates the data and control planes (the packets and the logic that determines what to do with those packets). The network hardware is then connected and mapped out in software, and network admins are able to manage the entire network from a software interface. They are also able to specialize their network and add new functionality by writing their own code and deploying it across the network.

the idea of a truly modular virtualized network that allows control from a software GUI is really cool. It is a big shift in networking to a programmable, open, and modular network controlled via software software that will make managing large scale networks much easier.

Cisco is now working aggressilvely to safeguard against the SDN fever and had recently invested $100 Million in a company named - Insieme. This is not only to save their market share but also save the millions of job for network engineers and administrators, No doubt SDN will open its own channel of knowledge, learning and opportunities but They way SDN operates, we can expect a huge fall in the number of networking positions worldwide.