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Intelligent automation and the WAN: Is SD-WAN moving mainstream?

Take-up of software-defined networking in corporates is slower than expected. Where have we reached on the journey to software-controlled networks – and SD-WAN in particular – becoming the norm?

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Sometimes in the modern era, a new technology sweeps in and adoption by business is swift because it’s a certified game-changer – desktop PCs, email or word processors, say. But history also tells us this kind of step-change is the exception.

Running large, complex businesses is multifaceted, with thousands of moving parts – people, process, technology, data analytics – to consider. It means most change that we see is incremental in how it unfolds – and even more so if the benefits and scope of a technology are not that easy to pin down.

When it comes to networks, and particularly wide area networks, the shift to enterprises taking control with a software-defined approach, through software-defined wide area networking (SD-WAN), is happening more and more, for sure, but it’s also not sweeping through as some predicted.

What’s the story behind the journey so far? And if the cost-savings of running SD-WANs versus traditional networks aren’t quite there in many cases, are network managers still missing the point that SD-WAN can deliver other benefits right now?

What’s happening in the WAN?

First, let’s briefly take a step back. Software-defined networks (SDN) are the future; of that there is surely little argument. In the next 10 years and beyond, SDN – and especially SD-WAN, using multiple carriers’ infrastructure – will become the norm as the benefits in agility and function come through and proliferate across everything that goes on in networks.

But what about the here and now? It turns out the transition is hard for many IT buyers to rationalise because the benefit of an investment in SD-WAN is often not clear-cut when weighing resilience, flexibility and value.

This is partly because there are lots of variables in different markets in relation to SD-WAN for enterprises to ponder – and variables that give the lie to baseline justifications about what SD-WAN delivers.

Most can be disputed, but some of the arguments, let’s remind ourselves, are that SD-WAN will usurp current networks.

Advantages of SD-WAN

It’s cheaper to run day-to-day: SD-WAN will deliver cost reductions as internet access is cheaper than MPLS, the argument goes. The thing is, that’s just not true across the board. In Europe, and especially in the UK, internet access costs are far closer to MPLS and in many customer networks the cost of MPLS is lower than that of providing internet. When you add in security considerations and firewall costs, the internet can look less attractive.

It lets you cut bandwidth and circuits: However, in reality the cost of SD-WAN cannot usually be justified on the grounds of cost savings by reducing bandwidth or the number of circuits. SD-WAN can, however, maintain business continuity at times of congestion or failure so is best viewed as an investment in productivity and customer service, more than a route to making savings.

It speeds up applications and cuts network data: Control of an applications layer is part of SD-WAN’s promise, but application acceleration is around in different guises and there is scope to cut latency and traffic in various ways, so it’s not quite a game-changer.

It speeds up future network deployments: That’s the theory, and it will happen, but for now networks are often made of copper and coaxial cables with engineers working in holes and up poles for connectivity by hand, with some form of device being deployed before circuits can be used. In time, carriers will be able to deploy and light services faster than they do today, with most places pre-fibred and ready for central deployment, but for now that vision isn’t a widespread reality.

How enterprises buy SD-WAN today

If the headlines don’t always quite deliver, what is the trigger for businesses to roll out SD-WAN today?

“We think this is a really interesting time in the market,” says Nick Johnson, chief executive of UK-based SD-WAN specialist Evolving Networks. “Acceptance of SD-WAN as a product is growing, but every conversation we have with a company weighing up SD-WAN is naturally unique. Not surprisingly, many approach us with immediate issues to resolve rather than a strategic vision to invest in a next-gen network.”

What Johnson says is true of many enterprises today is that their networks have organically expanded and become more complex, so a fix that layers in SD-WAN often looks a good value-add, but the opportunity to look at a WAN in the round is often worth taking.

“Many will have a core corporate MPLS plus extras like internet breakout. It’s common for CIOs and network managers to be unhappy with their ISPs, too. One thing with the UK market is that some SD-WAN offers out there don’t really address the risks around connectivity, even though it’s fundamental.

“Companies need an integrated SD-WAN platform, really, with no disconnect between the software and infrastructure. When you take US-developed software and apply it with a UK ISP, we think that’s a risk. UK broadband is cheap but doesn’t always compete on quality and service levels in the same way as in the US.”

SD-WAN in practice – Vindis

In practice, of course, every SD-WAN roll-out is down to the fit with business processes and what needs to be upgraded. As more and more core business applications move to the cloud, for example, that’s a part of the picture for many enterprises – on-premises servers can be retired when a resilient SD-WAN goes in.

If a root-and-branch WAN overhaul or roll-out isn’t the most common place to start with SD-WAN, for Vindis Group – a family-owned car dealerships business with 19 vehicle dealerships and five other sites supporting its commercial operations – it was a much-needed investment in 2016.

“The business had 24 sites with some ADSL services, no real WAN and local systems at each site relying heavily on ISDN lines,” says Nic Elliot, Evolving Networks’ CTO. “When we came in there was inadequate resilience in the branches’ external connectivity and no internet access management or control, plus no infrastructure to support VoIP. There were also no network connections between sites or between branch offices and HQ.”

With servers at every branch office, with all the attendant management costs and complexity that can bring with it, Elliot says increasing bandwidth and resilience at all sites with a managed WAN was a clear business priority.

“Centralising business systems at Vindis Group HQ, including group-wide adoption of a new centralised dealer management system and Microsoft Exchange, was part of the overhaul,” says Elliot.

An SD-WAN running over bonded ADSL, FTTC [fibre-to-the-cabinet] and Ethernet connections was implemented for all sites. The SD-WAN uses connectivity provided by us including a cross-carrier network, with a mix of Ethernet services from Virgin, BT and TalkTalk, and bonded ADSL and FTTC at sites for which Ethernet was either non-viable or not cost effective. It’s a robust set-up that means key business systems are now hosted at Vindis HQ, which is real step-change.”

To manage this complexity, the SD-WAN is making automatic, intelligent policy-based routing decisions for all data transfers. As well as allowing for the automation of routing and quality decisions, this abstracting of network control to the WAN also enables transparent failover in the event of circuit failure.

Read more about SD-WAN technology

Elliot says for Vindis the SD-WAN has allowed the group to make cost savings by using VoIP in place of traditional telephony, as well as seeing savings arising from central monitoring and management of all internet usage.

“As you would expect, there are also savings arising from eliminating branch office servers and relocating central business systems to the HQ,” he adds.

This long list of benefits from a big-bang SD-WAN upgrade is unusual in that most businesses take a far more incremental approach to a networks investment, but it certainly showcases some of the potential in software-defined networking.

The analyst view – pilots and process

If some suppliers offering SD-WAN emphasise how the renewal of contracts on MPLS circuits is often the trigger for enterprises to start a conversation about SD-WAN, Gartner analyst Neil Rickard makes the essential point that an SD-WAN set-up most likely makes use of MPLS rather than replacing it.

“You don’t swap one for the other. Any rethink in relation to a WAN is premised on building better, more agile networks. You might cut back on MPLS but it would be odd to look to escape it altogether. In essence, SD-WAN is a new generation of edge device, and it gives you any connectivity – not just broadband internet but whatever is fit for purpose.”

Rickard makes the point that adoption of SD-WAN has to be approached with the right critical mindset to make the most of what is still a relatively immature proposition in some respects.

“This is a market historically characterised, until quite recently, by the purchase of reliable routers from large suppliers. With SD-WAN today there are already over 40 viable vendors in the marketplace with products, but all have different approaches and different feature benefits. To that extent, it always makes sense for an enterprise to be quite process-driven and granular and analytical when weighing up SD-WAN – and that includes doing a small-scale pilot to understand the risks and the benefits.”

Rickard adds that the rise of SD-WAN as a managed service is also changing the landscape again.

“How do enterprises source SD-WAN? Once there were no managed providers offering it – you had to buy the boxes and run your network. Now, though, we do have managed SD-WAN service providers from network-owning telcos and more. Many organisations will like it as a managed service, in fact, but it’s not a cure-all.

“The temptation with SD-WAN is to believe the devices are all self-learning and adaptable and it will make running the network easy. But that is false because most networking is still defined by the underlying links. Troubleshooting should get easier with SD-WAN, for sure, but the problems to be fixed won’t just go away. The savings story with SD-WAN is not so much to do with the underlying network but more about the promise of better controls.”

Culture change and automation

The human element when it comes to any SD-WAN roll-out is also fundamental, as Patrick Hubbard, head geek at IT monitoring outfit SolarWinds, is keen to emphasise.

“There are two sides to this. There is the caution that many network managers might naturally feel about backing an automation technology that should in theory cut network roles in an organisation. And there is the way that any learning to make the full use of SD-WAN should deliver real transformation to an enterprise,” he says.

“In other words, there is lots to chew on when it comes SD-WAN. It shouldn’t just be approached as an upgrade on the wide area network but for the transformative potential of the control and analytics it offers,” says Hubbard.

“Of course existing networks are business-critical and often bespoke and manually configured – that’s the usual context. It means it is usually too risky to just jump in and undertake a big overhaul, as in your unusual example, but that doesn’t mean that a sensitive, small-scale upgrade shouldn’t also be a jumping off point for long-term strategic change.”

Hubbard argues that the range of issues to consider with SD-WAN and wide area networks generally is extensive in technical terms, but the cultural shift mustn’t be ignored by network managers.

“Yes, you need to look at every element of a network and what tools will work – 4G wireless, whatever – but there are so many other aspects to understand when automation, machine learning and the software layer is added.

“Those working on the network need to adopt more of a DevOps mentality in relation to SD-WAN and recognise that you can automate yourself into a new skillset and a new career. It’s a big step away from trying to keep the lights with a traditional network – but exciting, too.

Troubleshooting or transformation?

In a sense, what Hubbard and others are arguing is that SD-WAN, whatever its current substantial shortcomings and ROI gaps, does offer the promise of a way ahead that’s properly transformative: a single view of the network, with controls and analytics that are more like programming in their functionality and scope.

“The days of reactive networks firefighting have to be consigned to history soon. SD-WAN is at least about being proactive and taking control with software. It needs to be measured for that potential just as much as for any projected hardware cost-savings.

“We are still getting used to the transformative potential of automation – still adapting to what it means in practice. It does often mean you can do things that just weren’t possible previously, and that means you have to recalibrate as an organisation. What’s the real bottom-line advantage to making this step?”

This was last published in September 2018

Read more on Software-defined networking (SDN)

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