Every 25 years or so, telecom networks get totally redesigned. The last big re-build came with the internet in the early 1990s. Now "IP networking" technology is giving way to another technology cycle known as software defined networking. SDN is a new architecture for telecom networks in which the emphasis shifts from hardware to software.
The result is a faster, more efficient and cost-effective data network. Since the network is "defined" by software - not hardware - control can be centralized, network technology can be upgraded faster and innovation is no longer restricted to within the walled gardens of the operators. Third-party app developers will be able to program the network.
SDN will be a hugely disruptive technology cycle because it fundamentally changes who controls the telecom network.
The idea behind SDN technology first appeared in a research paper about using software to control network access published by Stanford University graduates in 2006, which stipulated that "No user, switch, or end-host has more information than it absolutely needs."
Then in 2008 the concept of programming a network was adopted into OpenFlow, an open-source communications protocol that gives access to the forwarding plane of a network switch or router over a telecom network. By 2011 the term "software-defined networking" had been coined to describe the process of using a software controller to program data flows in a network.
European Telecommunications Standards Institute
Network Functions Virtualization (NFV)