Blog · 16 Feb 2018

SD-WAN: beyond the buzzword

Find out why our SD-WAN experts think it's a networking technology that might not be for everyone.

Paul Taylor
Senior Deal Architect, BT

SD-WAN can bring a lot to your organisation

With it, you can fundamentally transform the way you work, with minimal disturbance to the daily operational activities you may have with a traditional network. It can provide a transport-independent overlay to your existing environment, allowing you to consider consumer-quality transport services where you need them, while giving you clear visibility of your network, globally. The internet might be a lower-cost service, but it’s limited in the SLA and repair times that exist with a private network platform.

SD-WAN can help to take away a lot of the complexity you’d find in a traditional network from a routing and configuration perspective. Bringing together multiple transport providers into one simple solution takes a careful planning and implementation plan which allows the complexity and risk to be understood and mitigated. It enables better decision making in terms of application performance routing, by providing data that lets you act on real visibility into how your traffic is performing, rather than how you think it might be.

And, in case you’re still not persuaded, it brings agility, granularity and flexibility into your overall deployments.

Here’s the catch    

With that said, we don’t think SD-WAN is the answer to every business requirement. And we don’t think it’s a solution that’ll work for every organisation.

If you’re considering SD-WAN, the question is, are you doing it because you want to jump on an industry trend, or have you truly considered the business benefits for your organisation?

If your answer is the former, it’s still possible that SD-WAN is a solution that could work for you. But we would suggest you talk with a provider such as BT before you invest any time, energy or money.

If you’re in the latter group, the next step may be the same.

You might now be wondering which kinds of business can benefit the most from SD-WAN? Well, there’s no one answer to that. But there are certain business situations where SD-WAN would be a useful solution.  

Considering the criticality of the business applications and their network requirements from a perspective of their ability to tolerate latency, jitter and packet loss, will an internet-based transport solution meet all the requirements?

More bandwidth will always help, but the trade-off between cost and quality is key to the ability to continue to deliver the application expectations of the business. Yes, you can have higher bandwidths over the internet at a lower cost, but available bandwidth is the same, as the controls required to secure the paths is an additional overhead.

Can your business accept the increased bandwidth and path selection with limited performance metrics? Or are the guarantees associated with a private SLA-based transport still a requirement?

Overlay networks leverage the underlying transport services, but they have no ability to affect the quality of them.

Knowing you have an issue, identified by the overlay SD-WAN solution, is great, but how do you fix the internet? Where is the source of the issue? How do you affect a service provider who you have no contract with? Who do you call when you buy a commodity low-cost transport?

Also, keep in mind that to enable an e2e service view which includes capacity and resolution management, it’s better to manage (or at least be responsible for) the underlay components — using services that meet the business applications being run across the network.

Business situations that benefit from SD-WAN

Pop-up sites

SD-WAN allows for a site to be set up in a matter of hours. As long as a site has internet services and has met the pre-requisites for service enablement, it’s a simple process to bring a site live with minimal technical intervention at a location.

Retail Branches

Uniformity of configuration, the ability to respond quickly to a potential security risk with a few simple actions, all in a centralised management dashboard mean that prevention is a reality rather than a hope. Simplicity in delivery, one solution independent of the local network service provider, and allowing business-critical traffic to be prioritised over less important applications — all give you visibility, control and flexibility in growing or shrinking the business estate.


Acquisitions or divestitures are important, but network segregation and security for an untrusted partner/business division make businesses nervous. Allowing controls to be put in place that limit where something that needs to connect, or not connect, can be enabled.

One truth

SD-WAN overlay networks can provide a view of the service that’s independent of the underlays. This is useful if there are multiple underlay networks.

The future

If your business fits any of these situations, it’s certainly worth having a conversation about SD-WAN. But what about the technologies of the future?

Vendors such as Cisco, VMware and Nokia all have capabilities that drive SDN capabilities on both the edge and in the data centre. How these come together is still a little unclear, but they are in the roadmaps of these vendors rather than deliverables today. And it’s clear that SD-WAN won’t be the only technology you should look at. It will, however, most likely be a part of any future network you invest in.

The future won’t just be about SD-WAN, but it will be about how communications over a network happen.

What next?

If you’re now wondering exactly how your organisation can get SD-WAN right, the best course of action is to get in touch with us today. We can work with you to identify your opportunities and help you decide if SD-WAN is right for you, and how you can deliver the benefits to your organisation.