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What is
Network Function Virtualization?

NFV? What’s it all about? A back to basics look at this technology.

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Network equipment – Likes switches, routers, telephone exchanges – all live in their own individual box. A box that really only does one thing, but does it well.

Communication networks are made up of lots of boxes that are used to deliver communication and data services to you and me.


Need to provide a different service somewhere? That’s a new box.

Need to support more users or data? Swap out the old box for a bigger box.

That’s inefficient, and expensive for whoever runs the network. More boxes means more space, power, more things that might break or need replacing. And for us users of the network? It’s frustrating because it takes so long for services to be upgraded or improved, due to all those boxes needing to be moved around or replaced.


But why have so many boxes?

Modern networking is about moving standard packets of data over networks, with a bit of data analysis and modification along the way.


Isn’t that what plain, simple computers do? Isn’t software that runs on computers able to process and move data?


Yes, yes it can.


So let’s write some software to replace all of those boxes…


Welcome to NFV

Today, network equipment fulfilling very different roles already share very similar technology inside the box. That’s thanks to the increasing performance of Intel based servers and the reduction in cost of hardware components to process data packets.

Devices used in homes, offices and even in busy parts of a telco’s network are mostly generic hardware you could buy from Radio Shack. In a nice box. It’s software that does the real work of implementing services, or communications protocols.

So why not get rid of the separate boxes and run the software that does the actual work on a computer? And if that computer can run more than one software program at a time, then you can replace lots of boxes with a single computer.

This is exactly what Network Function Virtualization – NFV – tries to achieve.

Take one or more computers providing data storage, compute resources and network connections.

Virtualise the hardware, which put very simply allows all those resources to be split up in to separate units known as Virtual Machines. Then in each Virtual Machine a Virtual Network Function is installed.


As the name suggests a VNF is a software version of the traditional network equipment box. It’s the software that does the smart stuff. Virtualization means the computer can be configured to run multiple Virtual Network Functions.

So, I can replace not just one box but several boxes with simple, cheap computers.


Because VNFs are software, they can be installed and upgraded much quicker than deploying new hardware. And because the compute resources are virtualized, they can easily be reassigned between VMs to increase the performance of a network function, if user numbers or data traffic rates increase.

How is NFV Being Used?

In the Office. NFV can be found in offices where it delivers a wide range of communication services, using far fewer boxes while allowing the communication service provider to up-sell new services or upgrade the customer on-demand.

In the CSP’s Network. In communication networks, NFV is starting to be found at the edge of the network, where multiple, specialized boxes are usually found delivering services to customers or acting as gateways between different communications systems.


Network changes can be made without having to buy and ship more boxes, and without sending an engineer to site. And the CSP can more readily respond to peaks in demand by turning up the resources dedicated to busy services.


When is NFV Arriving?

It’s here today, but there are several challenges to overcome before NFV moves in to the main stream. There’s not enough standardization between NFV solutions yet, leading to incompatibility with network functions. And telcos using NFV need new systems for installing, managing and selling services on the virtualization networks


Perhaps the biggest challenge comes from NFVs best features: Network configurations and customer services can change much more quickly. Daily or even hourly. Most telcos are used to making such changes over the period of weeks or months with their traditional network devices. Can they keep up with the pace of NFV?


Virtualization of IT systems started to become common 10-15 years ago. Today, whether a single server in an office, or a hundred servers in a data center, virtualization is the norm. And the same will eventually be true for communication networks – because it’s the best way to make efficient and flexible use of the network while serving the end users’ needs.

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