Network function virtualization

SDN has decoupling of hardware and software as its core principle. This has manifested itself as a concept called network function virtualization (NFV), where a specific network function, for example, Network Address Translation (NAT) or a Firewall function is virtualized and taken out on external hardware or even a standard x86 processor as a virtual machine. NFV has emerged as a technology that can help scale up the network in a more agile manner. For example, if the traffic at a branch has increased, and there is a need to add more firewalling capacity to the network, additional network functions can be turned on, and cascaded to add capacity to meet the enhanced demand. NFV treats network functions such as virtual machines/applications, and hence can be moved around the network and turned on and off on demand.