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SD-WAN: The magic solution to all my problems?

Maybe—but it depends on another factor. Read on…

The idea isn’t new. Nor is the technology. But with its value proposition clearer by the day, even Gartner agrees SD-WAN is having “a moment”. From boardroom to boxroom, the cry goes up: “Let’s get SD-WAN. That’ll solve everything!”

But let’s be clear. SD-WAN isn’t one flavour of technology. Even less one-size-fits all. It’s not an architecture, or a managed service, or a “solution” that plugs and plays straight from the box. As with all things IT, there are no quick fixes, no silver bullets, no shortcuts.

To make the most of SD-WAN’s potential …. you need the right technologies working with it.

With this achieved, SD-WAN can deliver the critical success factors of cost / value / function as a long-term solution for your business networking—whether your current setup is MPLS by carrier, Tier-1 on the backbone, or a hybrid of these and others. It’s all about focussing on what matters.

So what does matter?

Let’s push aside the marketing magic, and make some magic of our own—the business drivers for SD-WAN in the real world.

Defining the software-defined: what is SD-WAN?

First up is to understand what SD-WAN is and isn’t—in a way that’d make sense to your C-Level people. Including those with no skin in the technology game.

Software-defined Wide Area Networking often sounds like some sort of standard protocol, like IP. But what SD-WAN is not is a network architecture. Nor is it a managed service (on its own), like MPLS, with fixed routing tables operating on private circuits. And it’s certainly not broadband service provision. In fact, these are precisely the decisions you need to think about to get the most from SD-WAN.

Think of it as a product.

So what is it? It’s a product. A product overlaid on other technologies that enable it to function well, the same way cars need roads. So while SD-WAN solutions are by definition software-based, unlocking their value depends on hardware infrastructure like any other application.

The value of an SD-WAN is in how it makes better use of networking infrastructure—whatever that infrastructure is. You’ll see SD-WANs operating over private networks and connected sites, within data centres outside and inhouse, even whizzing around on traditional MPLS.

“SD-WANs provide a lightweight replacement for traditional WAN routers to transport traffic across mediums - such as MPLS, internet, [and] 4G/LTE.”

Dynamic change trumps static samey-ness.

For a long time in networking—and still true for many organisations today—the value of a network came from keeping the fizzing, bubbling, anything-goes nature of packet switching under control.

Internet Protocol builds its own pathways and routes around damage, yes. But in an MNC of scale, all that sidestepping and shuffling cost bandwidth. So technologies like MPLS guided those packets with Stentorian firmness, setting fixed routing tables your data had no choice but to follow.

An SD-WAN harks back to that fizzy, bubbly idea … and makes it better. WANs defined in software use the flexibility of IP in an improved way, actively measuring the performance of each routing circuit to optimise and improve, nearly in real time.

“The point of SD-WAN is to bring hands-off flexibility and adaptability to your network infrastructure—provisioning the resources you need, when you need them.”

An SD-WAN’s algorithms constantly look for better paths for your data, optimising every connection, always looking for the best way to get packets from A to B. That’s what an SD-WAN does—and the best do it very well indeed. Which is our first reason for putting it on your consideration list.

Of course, for this to work, you need an infrastructure capable of making it shine. Of which more later.

VPN as a fundamental feature.

Virtualising the WAN like this carries another benefit: it has VPN capabilities practically by definition. Encrypted with the usual bells and whistles—128 bits and up—SD-WAN traffic is secured at a basic level, whether 0% or 100% of it is carried on public network infrastructure. And this doesn’t preclude you adding additional security at the authentication or application level.

In other words, it’s secure by design. Which makes a great base for your inhouse firewall or access gateways. End-to-end privacy for your business information, whatever device needs it. In fact, if SD-WAN has an overarching design goal, this is it—to keep your data flowing securely across different chunks of network gear, without caring too much what that hardware is.

Now the caveat. Whatever those bits and pieces of technology are, they still need hygiene factors: reliability, availability, capacity, speed. So once again, SD-WAN performance depends on network infrastructure.

With that in mind, here’s the real point of difference between a poor SD-WAN … and a terrific one.

The not-so-secret secret.

To restate our theme: if your connectivity between sites isn’t fast and reliable, the SD-WAN will suffer. You can’t change the laws of physics … or the needs of virtualisation algorithms. It’s all about the underlay.

And with recent improvements in middle-mile and last-mile connectivity among the world’s public network providers (such as local ISPs and backbone operators) many MNCs are discovering third-party internet solutions provide that underlay. Non-contested business broadband with guaranteed service levels can offer a step change in service—with a step down in costs.

Now that’s a winning combo.

Imagine your SD-WAN solution running not on your pricey MPLS setup, or your reliable but limited Tier-1 connection, or even your private leased line …. But on business broadband over the public internet.

It doesn’t need to happen all at once. Or even need you to rip-and-replace. SD-WAN is flexible. A global organisation with (say) 200 sites can deploy broadband internet at non-critical sites first, then move to business-critical, and finally mission-critical applications, running down expensive legacy technologies like MPLS as and when it makes business sense to do so. All maintaining complete business continuity as you roll out.

“A global organisation with (say) 200 sites can deploy broadband internet at non-critical sites first, then move to business-critical, and finally mission-critical applications, running down expensive legacy technologies like MPLS as and when it makes business sense to do so. All maintaining complete business continuity as you roll out.”

For many enterprises today, SD-WAN over business broadband is the solution of tomorrow. And tomorrow’s not far away.

Read: Five years of SD-WAN migration stories, five takeaways.

Conclusion - magic bullet or not?

SD-WANs are a great technology with a lot to offer today’s multinationals. So is SD-WAN your magic solution? No. But it can be … if you treat the underlay that supports it with the respect it deserves.

SD-WAN success is measured by the reliability, availability, and overall service levels of your infrastructure. On your network at present, some parts may be more cost-effective than others—and if you’re coming from an MPLS setup, SD-WAN over business internet will definitely carry a cost advantage.

Why not look at how deploying SD-WAN with a business-capable broadband or DIA solution, like those from connectivity experts Globalinternet, could deliver for your organisation?