By BT

17 Sep 2019

After more than 20 years of stability, networks are going through a period of dramatic transformation. BT looks beyond the hype at the real benefits of virtualisation.


Networks are transforming to SD-WAN solutions, built on hybrid networks. These are delivering many advantages in terms of flexibility, agility, control, visibility and cost savings, but they still involve connecting a network to a box, plus more boxes for any additional services you want to run on the network.

It is the next phase of networks which will be truly transformational. Instead of boxes, virtualised versions of a range of different services can be deployed on edge devices or from the cloud. Virtualisation will truly deliver the flexibility and agility required for a digital future. 

The global NFV/SDN market will grow at a CAGR of 25 per cent between 2018 and 2023.

The start of the virtualisation journey

Like many of the other recent transformations in the network space, we’re seeing a lot of hype in the market.

Part of the hype is because virtualisation offers such huge advantages. Virtualisation means that services such as routing, security, application services and SD-WAN that previously were supplied as hardware, can be supplied as software. Once virtual platforms are deployed key functions such as firewalls can be rolled out anywhere in the world without the need to physically deploy additional equipment. It offers customers flexibility by disaggregating the hardware, software and service, giving vendor choice, agile deployment options, and the ability to change quickly.

Customers we talk to believe it will offer advantages in agility, flexibility and control, but still view it as an emerging technology with inherent risks and uncertainty. Therefore, as they move towards virtualisation they want to know what the real potential and indeed limitations of the technology are.

Questions they are asking include:

1 - How do I move from my current environment to a virtualised one?

2 - What will be the operational benefit and impact?

3 - How do I build my business case to support my adoption?

Answering these questions and plotting a path to virtualisation combines a number of skills, including network designers, virtualisation technology experts, service and migration experts and functional expertise in areas such as security and network optimisation.  As one of the inventors of Network Functions Virtualisation (NFV), we’ve brought our experts together to work closely with customers, including a “try before you buy” test and trial capability.

But the benefits are already real

A number of our large, global enterprise customers are already making that journey and we’re working with them to deploy virtualised services. A common use case we’re seeing currently is managing refresh cycles, a time consuming and expensive task. One customer is reducing the risks of a lack of alignment in their hardware refresh cycle in their estate by moving from a staggered hardware refresh approach to deploying a virtual approach, which also allowed them to manage immediate end of life concerns and also plan for the future.

Another customer faced a short term driver of hardware reaching end of life, but also wanted to adopt SD-WAN to introduce greater agility in their network estate. Virtualising gave them an immediate solution to the end of life, increased their agility on deployment and management and introduced a roadmap to SD-WAN.

And finally, we’ve seen it used to address performance issues at key sites globally. The customer had globally dispersed sites with poor performance of critical business apps. WAN optimisation allowed them to address the performance issues, but they now also have the flexibility to remove the optimisation at a later date. With commercial flexibility, stopping a service is easier, like turning off a tap, with no hardware to remove.

Simplicity based on complexity

The simplicity of the benefits of virtualisation is built on complexity. 

Just like the Apple App Store or Google Play, whilst it’s relatively easy to create an app, you need a platform to host them on. Virtualisation requires an infrastructure to virtualise and deploy your own functions. Deploying a new service is easy, when you’ve done it before. But if you’re new to it, you need to put the processes in place, test the processes, secure the process etc. Edge devices need to be designed, deployed and tested. And this all needs support and management.

As the technology becomes mainstream, there is also complexity involved in running multiple virtual network functions (VNFs) on a common edge device. Service Chaining is bringing together different VNFs, applying and coordinating any change to one function across the others in the chain.

To create the platform underpinning virtualisation is complex, expensive and requires specialist skills. We’re not seeing many customers looking at the DIY route yet, particularly as there is a scarcity of the skills needed.

Virtualisation is built on choice

Virtualisation is still new, and we’re working hand in hand with customers and our network of partners to help understand what’s applicable to virtualisation, how to design and deploy services and to build a business case. The business case is key because of the high current cost of VNF licensing and the number of VNFs which are needed to make the case work.

One area which is key in virtualisation is thinking about the in-life management of services. Deploying or making a change to one VNF could impact — or even stop — another. If one of these functions is a firewall the effect could be severe enough to block all connectivity to a site. If repeated across all sites, it could shut down a network. That’s where services like Service Chaining come in and where a service provider can play such a key role as they will do all the hard work for you. They should design, build and test your service chains as well as manage in-life. 

'As the ecosystem of VNFs grows, it’s important to have the confidence to rapidly deploy each new function without the worry of disrupting the others.' - Adrian Comley, General manager, Dynamic Network Services

For us, virtualisation is built on choice. We’ve created the platform to enable these services, a complex, global solution which can scale for hundreds of organisations and thousands of sites. We offer choice at the edge for Cisco and non-Cisco options. For simpler solutions we can also offer VNFs on existing SD-WAN solutions. We also offer a range of VNF options from the leading vendors.

As Ovum have identified, there is a growing importance of ‘bring your own’ VNF. Although very few organisations can do this, it's important because it allows the customer to on-board VNFs or IoT applications and make computing at the edge a reality.  That's why we also offer the opportunity to virtualise the customer’s own network functions, so if they have a particular network function which is key to the operation of their organisation then we can virtualise it for simple deployment.  

The future is virtualisation

There will undoubtedly be further changes in the landscape brought about by evolving customer demands, technology development and other factors. We’re already seeing even greater choice of VNFs and edge services, coupled with greater orchestration and management options.

We were one of the early pioneers around NFV and we continue to develop our service, platform and people in this area to ensure that wherever you are on the journey to virtualisation and however the landscape evolves, we can support you.

Find out how to boost your flexibility and control with virtualisation.

BT's report on the cornerstone of network transformation is available to download here

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