SD WAN | What Does And Doesn’t The Technology Offer | Fully Explained


Over that last couple of years, SD WAN technology has gone from being something only used by early adopters – to being a technology that’s underpinning tens of thousands of business networks.

As with most early tech, there’s some great and useful information to be found online about what it can do and what’s possible. That said, there are also plenty of companies who will happily tell you that it’s SD WAN or bust for your business!

To help you cut through the noise, we’re going to look at what SD WAN is and what it might offer your company – as well as a couple of claims that the tech might not be ready to back up.

A software defined wide area network (SD WAN)

It’s useful to line up a traditional wide area network (WAN) to an SD WAN for a full illustration of what the technology offers.

In truth, almost all multi-site businesses have a WAN of sorts. In its most simple guise, a WAN is a series of branch locations connected to one central IT provision. That provision usually provides application access to those branches. Ordinarily, those branch locations would have their own dedicated internet circuit connection – which is then configured to work as part of a virtual private network – giving the company its own secure network across the wider internet.

As well as housing the company’s services and applications, the firm’s IT HQ will generally also be where their IT team works from.

What does SD WAN do differently?

SD WAN doesn’t change how the concept of a WAN works – instead, it’s a system that offers an additional layer of control. As such, the product won’t replace anything on your network – instead, it functions as an overlay, connecting to each of your devices and managing each of your connections.

Since SD WAN works to unify every part of your network – for the purpose of centralized control, it also means that you gain a single, unified interface that allows control of all your devices.

This is perhaps one of the most significant aspects of SD WAN from a business point of view.

Of course, it’s not all about control.

There are a host of different languages that devices tend to use to communicate across your network. For example, data that are sent over a wireless cellular connection is handled in a slightly different way to information that’s sent over a traditional wired connection. SD WAN virtualizes this language – so different connections can be used together. If it makes sense to connect one location with a VPN protected internet circuit – but another with a cellular 4G connection, the SD WAN allows that to happen.

Again, this is another point that is extremely powerful when it comes to flexibility of network design – especially around the provision of new sites.

What does SD WAN offer?

So, we’ve touched on a few points that SD WAN offers from a technology point of view – but it’s worth having a look at the tech from a business point of view. After all, the tech can be as sophisticated as you like – but unless it’s going to benefit your business, it’s probably not worth having.

Class of service

If you’ve got applications that are critical to the delivery of your business, then SD WAN delivers a lot more than a standard WAN setup.

Effectively, an SD WAN comes complete with a pathway control system. As a result, your highest priority traffic will find its way across your network even if there’s a significant load taking up bandwidth created elsewhere. SD WAN makes it simple to roll these class of service (COS) preferences quickly – rather than needing adjustments with each device.

As such, on-the-fly COS adjustments become very possible – which is great if you’ve got an ever-moving landscape.

As promised though, we are going to look at the limitations of SD WAN – and it’s fair to say that these COS adjustments do fall short of being the kind of functionality you would expect from an MPLS system. Where MPLS allows you to micromanage data from each application or user, SD WAN doesn’t offer this level of drill down just yet.

Provisioning new sites

As we’ve previously mentioned, SD WAN lets you control your systems using one, overall language – and that can be extremely valuable if you need to get sites up and running quickly.

The benefits are two-fold. Not only can you effectively get ‘hands on’ with devices that are on the other side of the world, but you can also make sure that there are no language barriers with connection types. So, if it’s quicker to get one site up and running with a series of 4G SIMs providing your connection – you can do so, even if you’re mixing in traditional circuits and broadband connections elsewhere.

Of course, your connection type is only part of the battle when you’re getting a new site up and running. After all, you still need to get the equipment there and get it plugged in. The thing is, if you can do this, your IT team can work remotely to finetune everything – so you’re still likely to save time, even if SD WAN isn’t a magic bullet solution to make site provisioning completely effortless.

Centralized security

In much the same way that support can be delivered from one central location, security can also be rolled out across your network from a central point when you’re using SD WAN.

With a bright spotlight shining on data security, having one central provision to provide and monitor your network security is a great step. Traditionally, network security has come in the form of a firewall that protects each physical location. Since SD WAN allows you to roll out any application to a series of locations, this also means security provision can be held centrally too. It’s important to talk to a provider who will be able to build a security solution into your network design – but if you do, you’re likely to find that it becomes simpler and more effective than having measures at each site.