What is software-defined Networking
SDNs are a fundamentally different way to think about networks. Technically, SDNs can be defined as the separation of the management, control and data-forwarding planes of networks. Many people, including technical individuals read that definition and say, “So what?”, but the separation of these planes has a profound impact on networks and enables things that have never been done before.
Historically, management, control and data forwarding were tightly coupled together. This meant each network device such as a router or a switch needed to be configured independently, typically through a cryptic command line interface (CLI), which makes operating a network challenging.
Any time a change needed to be made to the network, even a small one, each network device had to be reconfigured independently. For small networks, this is an annoyance. For medium and large networks, the manual nature of the work could bring things to a crawl. In fact, ZK Research conducted a study in 2017 and found that in large enterprises it took an average of four months to implement a change network wide.
This might have been fine a decade ago when businesses weren’t as dependent on their networks as they are today, and network changes were only made infrequently. In today’s digital era, companies compete on speed, and four months is far too slow for the network to keep up with the business.