What is SD WAN and what does it mean to you?

If you have an interest in IT networking for business, you may have heard some buzz about Software Defined Networking as part of a Wide Area Network – or, as it’s more commonly named – SD WAN.

For every informative article, post and tweet – there’s another that seems to have some misunderstanding about what exactly SD WAN is and what it can do for your IT network – so, to offer some clarity, we’ve put together a quick guide to SD WAN – what it is, what it isn’t – and what it could mean to you and your business.

What exactly is SD WAN?

To understand what SD WAN is, it’s important to understand what a wide area network (WAN) is first.

Essentially, the internet is a WAN; a series of connected devices over a geographical area. In business terms, a WAN tends to be a central hub that holds the servers and other main network infrastructure devices – and then a series of branches, offices, cloud services – and so forth.

Each of these locations is likely to have a local area network (LAN) – which, when connected to the internet and then connected to one-another, becomes a WAN. The centrally located resources can then be shared over the entire WAN, meaning access to software, storage and central systems is accessible to all.

SD-WAN – facts and fiction

SD WAN is an interesting concept – it doesn’t replace anything within your WAN, it simply provides an ‘overlay’, that’s to say, an additional control system over your WAN that’s provided by a piece of software.

That software is compatible with every device on your network and replaces the controls usually only accessed by syncing with the device in person. As such, you gain control over your networked devices, regardless of geographical location – from your SD WAN controls.

So, it certainly means that network technicians will be spending less time travelling around the country – but what else does it mean to businesses? We’ll take a look at some of the claims in the networking world – and check to see whether SD WAN will truly deliver…

• SD WAN will replace MPLS connections. 

Many people are talking about SD-WAN replacing the costly MPLS connections favoured by businesses that require many applications running over their sites. MPLS – or multiprotocol label switching – is a data-carrying technique that’s used in the highest-performance networks.

MPLS works by varying the paths and priorities shown to particular types of data, meaning traffic that is mission critical is offered a priority path through the network – and traffic of lower importance is further down the priority list. In essence, if an application is important, it’ll run quickly – and the system will constantly monitor the pathways to ensure they’re maximised for all traffic at all times.

SD WAN also offers a function like this – a managed Class of Service (CoS) system which will also work to prioritise traffic. However, the two systems are very different, MPLS is part of your infrastructure – whereas SD WAN overlays that infrastructure – and offers more than just CoS tweaks.

Are we going to see a software system completely do away with the need for hardware solutions? Probably not, but we may see a decrease in MPLS reliance in time…

• SD WAN will mean we can expand to new sites instantly

The idea of being able to configure hardware in an instant (and without leaving the office) is music to the ears of people who are tasked with getting remote locations up and running quickly.

Sadly, as we’ve already pointed out – SD WAN doesn’t replace hardware, it merely configures it – so if the hardware and connection isn’t in place, then your SD WAN has nothing to work with. Having SD WAN will help getting sites up and running – but only if there’s an existing connection in place, without that, you’re still at the mercy of long circuit installation times.

• SD WAN means I can manage bandwidth and traffic priority quickly

SD WAN providers make a lot of noise about how their systems can offer supreme quality of service versus traditional WAN management techniques.

In actual fact, a lot of this could be down to marketing hype. SD WAN solutions may be able to help your quality of service – but these are unlikely to be tweaks that can be made only with SD WAN. In actual fact, making sure your networking structure is as efficient as can be should always be your first step here – SD WAN may help you get the most out of what’s currently possible – but adjusting what’s possible is usually going to happen at a hardware level. 

• SD WAN makes using SaaS a better experience

If you’re rolling out Software as a Service (SaaS) applications across your WAN, then SD WAN can be beneficial – as you’ve got a central location that can ensure all your satellite operations are accessing the same application with the same speed and priority given to the data.

When you’ve got real-time applications, especially if end-users or customers are using those applications, then it’s crucial that they’re running to their maximum potential. Responding to WAN issues relating to SaaS applications without having someone in site can keep your business up and running when it matters the most. Whether this impacts you entirely depends on the SaaS applications you use – and how important they are to your business operation.

What will SD WAN offer your business?

Of course, everyone’s business networking requirements are different. Perhaps the points above are crucial to you – perhaps there are other questions and priorities you’ve got when streamlining your network.

You can learn more about what SD WAN is actually going to deliver here – and also understand a little more about its limitations. Whether or not it’s going to be right for your business depends a lot on how your network is currently being run; if you’ve got a managed service provider who’s fixing issues and installing devices before you even realise there’s a need – then you might not see a huge difference.

However – if you’ve got an over-stretched in-house IT department that spends a lot of time moving between sites, you might see a huge expression of relief come over their faces when you talk about the possibility of bringing SD-WAN into your business…