Network function virtualization (NFV) is a natural outgrowth of software-defined networking (SDN). Sometimes it’s confusing where one ends and the other starts. SDN deals with network architecture and control. NFV deals with moving the work of traditionally dedicated appliances. Then it goes to virtual services that can run on any suitable hardware. One can be present without the other, though SDN and NFV work well together.
But SDN technology also puts the network’s control logic into the software. This way SDN separates it from the data plane. It provides a single point of management for configuring and monitoring the network. Its best-known application is the SD-WAN. That allows to not limitate remote facilities with dedicated connections so they can connect to a network. It can connect them to the Internet or use private connections like MPLS, or it can use a combination of the two. It doesn’t deal with the implementation of network functions.
Greater hardware independence with NFV
In the past, SDN has relied on the traditional hardware building blocks of a network: routers, switches, load balancers, and so on. But actually, all these devices are computers with specialized hardware interfaces. Any machine with the appropriate hardware and interface cards can do the job.
The benefit of this approach is that the functionality doesn’t have to be on any particular computer. It can run on any qualified machine in the network. Virtual Network Function (VNF) is the name of a task that is carried out this way. It’s sometimes known as a virtual networking appliance. Several functions can run on the same computer, or one function can run on multiple machines for better performance.
Virtualization offers many advantages. It eliminates single points of failure in hardware. It’s more scalable. It allows easier management of upgrades. SDN virtualizes the management of the network. NFV carries the idea further with virtualization of its physical components.
SDN and NFV together
A software-defined network is a natural fit for virtualized functions. Virtualization applies to any function at Layer 3 or higher in the OSI model. A virtual router can hold an entire WAN together, providing DHCP and NAT services. This lets to reassign addresses from one location to another when necessary. A virtual firewall can likewise protect the entire network. It can also call on reserve computing power to keep up with heavy loads or DDoS attempts. A secondary virtual firewall can add protection for a, particularly sensitive subnet.
A virtual switch can manage redundant or load-balanced servers in different locations. This provides better uptime since a failure at one data center won’t take the entire service down.
With an SDN console and NFV orchestration software, the network manager can control all network functions from one location. This facilitates identification of issues and deployment of changes. The network runs more efficiently, there’s less need to travel, and the administrator has more time to deal with other issues.
NFV and subscriber networks
NFV is especially useful with subscriber networks, where distributing hardware upgrades is cumbersome if not impractical. It provides benefits with or without SDN technology. Moving network functions into software make easy to install and upgrade network functions for many sites.
Development, testing, and release cost less and are faster than with hardware appliances. It also reduces the time to market for new services. If a bug or vulnerability turns up, fixing it requires just pushing new software out.
SDN and NFV add up to a network architecture which is flexible, scalable, and easily managed and upgraded. They minimize dependence on dedicated hardware and fixed connections. This way makes easy for a network to expand and add functionality.