Software-Defined Networking as part of a Wide Area Network - more frequently referred to as SD WAN - is something you may well have heard about if you have a marked interest in IT networking for business.

Unfortunately, finding out exactly what SD WAN is and what it can mean for your business and IT network is something of a difficult task, as the internet is full of articles and posts containing numerous misunderstandings. This has led us to put together this helpful guide to SD WAN to assist businesses and individuals looking for the key facts.

What is SD WAN?

You’ll need a decent understanding of what exactly a Wide Area Network (a WAN) is in order to fully understand SD WAN.

A WAN is multiple devices all connected over a certain area. The internet itself is essentially a WAN. For a business, a WAN is usually a hub (which holds the servers and whatever other network infrastructure devices are being used) that is in the center of a series of branches, cloud services, offices, etc.

It is likely that each of a business’ locations will have a Local Area Network (a LAN), which becomes a WAN once it is connected to the internet, and then to the business’ other LANs. These grants access to all a business’ centrally located resources - including central systems, software, and storage - as they can all be shared over the entire WAN. 

Frequently Asked Questions About SD WAN

SD WAN provides a piece of software that gives users additional controls over their WAN. It doesn’t replace the WAN, or anything within it - think of it as an extra layer of control added over what already exists.

Every device on a network is compatible with the provided software which will replace the controls that users generally only have access to when they sync with a device in person. SD WAN grants control over all the devices on a network from wherever you are, any time, any place. If you want to add security considerations into the mix, this is possible too – as more and more providers are combining SD WAN and security tools to create ‘SASE’ – Secure Access Service Edge services.

So what will this mean for your business? Read on for a quick fact check on some of the many claims about SD WAN gathered from the wider networking world:

Will SD WAN means we can expand instantly to new sites?

Many people have been longing for a way to implement hardware instantly, to be able to quickly get remote locations working without needing to leave the office. 

Unfortunately, however, SD WAN simply provides controls for existing hardware, it has nothing to work with if your hardware isn’t already in place. With the right hardware and connections in place, SD WAN will definitely help get sites going, but if not, expect to still have to contend with lengthy circuit installation times.

Does SD WAN mean bandwidth and traffic priority can be quickly managed?

The higher quality service over traditional WAN management techniques is something SD WAN providers often boast about.

In truth though, it seems like providers may be promising slightly more than they can actually deliver on. While it’s true that SD WAN can add to the quality of your service, these improvements are unlikely to be made with SD WAN alone. SD WAN will definitely help you make the most of your current setup, but it’s important that your base hardware is as strong and efficient as possible in order to see the real results.

Will SD WAN replace existing MPLS connections?

Multiprotocol Label Switching, or MPLS, is a technique that high-performance networks utilise for data carrying. Many businesses that need to have a lot of applications running over their sites favor MPLS connections. However, MPLS connections can be costly, and there is a lot of buzz about whether SD WAN will replace them.

MPLS connections make sure that crucial network traffic is given a more direct path through the network, and it achieves this by giving different types of data different paths and priorities. As such, less important traffic is given a less direct route, as it is of lower priority. Essentially, the system is always checking up on pathways through the network to ensure that network traffic has the most appropriate route, so important applications are run the quickest.

A similar function is offered by SD WAN. Network traffic is managed and prioritized by a Class of Service (CoS) system. MPLS however is built into a network’s infrastructure, as opposed to SD WAN simply being an add-on to said infrastructure, meaning MPLS can be used for more than just making slight adjustments to CoS.

Does using SD WAN makes for a better experience using SaaS?

SD WAN can certainly be beneficial for you and your business if you’re utilizing SaaS (Software as a Service) applications over your WAN, as it means that your central hub can make sure that each of your satellite operations is able to access the same applications, with the data having the same priority and speed.

When dealing with real-time applications, it’s very important that they’re all running at their highest potential, especially when they’re being used by a business’ customers or end-users. Being able to remotely, from off-site, respond to WAN issues that relate to your SaaS applications can keep your business going at the most crucial times.

How much this affects you and your business is entirely up to which SaaS applications you are using, and how necessary they are for keeping your business operational.

What will using SD WAN really mean for your business?

Obviously, the networking requirements of each individual business are going to be different. The issues and points raised above could be very important to you, and you may well have some more questions relating to keeping your network as streamlined as possible.

If that’s the case, you should do your own research and learn even more about what SD WAN can actually do for your business, as well as gain more understanding about what it really can and can’t do. SD WAN could massively improve your business, but it all depends on how you are running your network at the moment. If, currently, you have a managed service provider who conducts installations and addresses any issue before the need for them becomes apparent, it’s entirely possible that with SD WAN you might not see much of a difference.

If, however, the opposite is true, and your in-house IT department has nightmares about being spread far too thin, having to spend crucial work time moving from site to site... introducing SD WAN into your business could make all these issues go away.