When you are around the tech industry for any length of time, you get used to certain technologies being talked about for years and years without ever seeming to come to full fruition. It happened with 5G, with IoT and countless others too numerous to mention.

Another that belongs on that list is SD-WAN – or software defined wide area network technology, to give it its full title. As far back as a decade ago, SD-WAN was being hailed as the heir apparent to MPLS (multiprotocol label switching) in networking infrastructure.

Cost effective and highly agile, SD-WAN seemed the natural solution to the mounting costs of MPLS as enterprise bandwidth demands accelerated. And yet by the end of the last decade, people were still mainly talking about the potential of SD-WAN rather than a mature technology making real waves.

Looking back, 2020 and the onset of the COVID-19 pandemic looks like it marked a sea change in SD-WAN’s fortunes – although perhaps not in the way anyone at the time expected. Figures suggest that when the pandemic hit, SD-WAN was just starting to find some momentum, with 61% of enterprises reporting they had started implementation at the start of that year.

But COVID-19 put the brakes on that in a dramatic fashion. A year later, the number of companies that had deployed or were in the process or deploying had almost halved to 36%.

Such a dramatic fall could have spelled the end of SD-WAN. And yet another year on, and market forecasts are predicting another dramatic upsurge in SD-WAN’s fortunes. Over the next six years, the SD-WAN market is forecast to grow at a massive CAGR of 26.2%, accelerating it from just under $1bn to over $5bn.

​What’s behind this rapid turnaround? It could well be that one of the major long term business and technology trends to emerge from the pandemic proves to be the making of SD-WAN. We’re talking, of course, about home and remote working.

How does SD-WAN support home working?

Let’s quickly recap what SD-WAN is. Software-defined networking (SDN) is an approach to networking management that replaces traditional hardware controllers (like routers and switches) with software equivalents. You still have an underlying hardware infrastructure to the network (like fibre optic cabling, wireless routers, hubs, repeaters, bridges etc). But the control layer is all done by software.

This makes SDN much more agile and dynamic than its hardware-based counterparts, not to mention more cost effective. You can run a network from a laptop, rather than having to have specialist engineers working with much more technically demanding (and often hard to access) physical equipment.

SD-WAN applies the principles (and benefits) of SDN to the wide area network – which in terms of business networking refers to how a single organisation or entity connects all of its branches and offices into a single coherent network over a large geographical area. While hard-ware based WAN solution like MPLS – which in effect creates a single physical circuit connecting dispersed points – have proven to be highly dependable, as mentioned, they also increase in cost the more points you join.

You can probably spot the issue of expanding a physical WAN to accommodate home working already. Instead of integrating maybe five or six branch offices or stores into a single network, you might suddenly find you need to connect 500 homes to allow staff to log into the network from home. Extending MPLS connections to so many points is a hugely complex and costly job.

But with SD-WAN, it becomes much more simple and cost effective. Using cloud-based SD-WAN as a service solutions and software clients, you can turn the physical infrastructure that normally delivers ordinary home broadband into an extension of the secure wide are network.

Why is SD-WAN better than a VPN?

But wait a moment, you might be thinking. Back in the old days (i.e. pre-pandemic) when I worked from home, didn’t I simply connect via a VPN?

VPNs, or virtual private networks, continue to be a viable option for connecting remotely but securely to a company network. But VPNs are session-based tools that users have to log into and out of again. With SD-WAN, you effectively redefine the network edge wherever you please (i.e. at the home of a member of staff), which means you can set up a permanent, persistent connection. No more frantic calls to IT when someone has forgotten their VPN log in (which could be a huge resource issue when you have large chunks of the workforce operating from home). Plus, whereas you have to install a VPN client on a device, with SD-WAN you can connect from any device.

Other benefits of SD-WAN over VPN include the fact that you get a high degree of control over how traffic is routed, whether that means going through the company data centre or direct to cloud services. That increases the level of network efficiency you can achieve, leading to smoother, slicker performance overall. It also means you can prioritise workloads, which is especially useful when workers are using more resource-intensive applications from home.