Network programmability

SDN allows the network to be managed/configured by a controller, and NFV enables adding, deleting, and moving network functions on demand. This entire thing, when put together has immense potential to change the conventional way of networking and make the networks more agile and flexible.

By taking inputs from the network with respect to traffic loads, congestion, and routing behavior and running advanced analytics, network operators can take decisions on the changes they require on the network at a given instant. These changes can then be deployed on the network in runtime by making routing changes, topology changes, or even augmenting network capacity with respect to network functions. All this is possible because of the open interfaces and standard based APIs that would allow any programmer to use these APIs and operate the network efficiently.

An example of this is seen in terms of Software Defined Wide Area Networks (SD-WAN). Imagine a network topology in which certain traffic has two paths from source to destination. This traffic can also be of multiple types, for examples, delay sensitive, loss sensitive, or loss and latency tolerant traffic. By analyzing the performance of the two paths from source to destination, the network operator can force certain traffic to take a path that would provide better performance for a specific traffic type.