Looking for the promised WAN

21 June 2018

When asked what makes SD-WAN so special, two words repeatedly come up: visibility and agility.

For instance, Orange Business Services (OBS) says an increasing number of its customers are using the internet alongside private access technologies such as MPLS as a way to gain access to cloud-based services and also to leverage cost-savings. 

“The thing that’s special about SD-WAN in these circumstances is that it gives a way of overlaying control, visibility and optimisation in this hybrid environment,” says  Richard Kitney, OBS’ hybrid connectivity specialist. “As we move to these new implementations, SD-WAN gives a dashboard to see what’s happening, and furthermore to be able to control that environment. And because it’s an over-the-top technology – i.e. a technology you can add to your existing infrastructure – you can add those features without a radical redesign.”

Many companies that have traditionally specialised in WAN optimisation technologies are now currently in the SD-WAN vanguard – Riverbed Technology is one of the key players here, and over the past few years it has partnered with the likes of Microsoft, Huawei, Zscaler as well as OBS to develop platforms and services. 

Steve Foster, Riverbed’s senior solutions engineering manager, believes SD-WAN represents the new generation of intent-based networking, giving the modern enterprise an agile platform that can be adapted quickly to business requirements. “It’s moving us from locally significant connectivity and routing – which is done by individually configuring network components, requiring complex configuration and effort to ensure network-wide policy – to a centrally orchestrated management system, simplifying the configuration of connectivity and availability policies. The ability to quickly extend WAN connectivity and services into cloud platforms has changed the way in which hybrid cloud infrastructure has been integrated into the enterprise.”

Aryaka claims that unlike legacy network technology, such as MPLS that takes months to deploy, its global SD-WAN platform is delivered as a service and can therefore be deployed within days. 

“SD-WAN is the biggest trend in enterprise networking today,” says the firm’s EMEA VP Ian McEwan. “It offers an entirely new way of managing a WAN across multiple locations. This technology enables the migration of an organisation’s network from hardware to software and represents a shift away from data centres and server rooms towards cloud and SaaS applications.”

This connection to the cloud means specialist platform providers such as Aryaka or Riverbed are now not the only ones banging the drum for SD-WAN. OBS was one of the early adopters in terms of service providers and more recently others like Virgin Media Business (VMB) have also signed-up, as its senior product manager Mark Conrad explains: 

“We’re seeing two things happening simultaneously in the market. One, we’ve seen enormous growth of SaaS-based offerings and applications as well as cloud service providers. Essentially this means that more of what takes place in business networks is on the internet and not in private data centres or on proprietary platforms.

“Two, as demand for these internet-based services grows, providing resilient, secure and quality assured networks with the capability to access them is becoming more challenging. Typically, that level of service has been the preserve of private networks such as MPLS IP VPN. However, those private networks are facing a challenge in a world which is cloud and internet first.”

For Conrad, what makes SD-WAN so special is that it bridges the gap between the internet, customer data centres, secure and private networks, quality of service, and quality of experience. “As an underlying technology which reaches into all of these domains, it allows users to take advantage of almost any technology in a way that’s inherently secure with high levels of service assurance, ultimately allowing IT managers to do more, not just with their connectivity but the applications and services that sit alongside it.”

Is SD-WAN for you?

Hughes Europe entered the SD-WAN market with the launch of its own platform last year (see News, Oct 2017 issue). The firm’s head of marketing Vanessa Armstrong says any organisation that wants to be future-proofed as it embarks on digitisation or is seeking to reduce the cost of running a distributed network will benefit from SD-WAN. But she also points out that businesses that operate from single site or very small estate may perhaps struggle to reap the rewards from the technology.

ICT solutions provider Axians agrees here. Chris Gilmour, the company’s technical practice lead, says that in practical terms, SD-WAN makes the most sense to businesses with 10 or more sites. “Fifty or so seems to be the sweet spot in terms of building a simple ROI model. The technology is especially useful in the wake of a merger or acquisition, as historically integrating two or more networks can be complex and painful.”

While there are few, if any, companies that would not benefit from SD-WAN, Riverbed’s Foster says the exceptions are customers that wouldn’t want to utilise hybrid MPLS/internet connectivity, connect to cloud services, or have multiple network links into sites, for example. He adds that some SD-WAN solutions have cloud hosted orchestration platforms that exclude some companies that may be restricted by regulatory considerations about using public cloud hosted services.

While not all SD-WAN features will deliver an immediate benefit to the user, OBS’ Kitney says there’s almost always something for an organisation to take advantage of. He says one compelling initial benefit will be in switching on application visibility before any customer goes headlong into delivering services to the cloud or re-architecting to a hybrid network topology. “That application visibility tells them a lot that they don’t already know; for example, what applications are running on the network, how they are the using the network, what bandwidth is being consumed, and where problems are. In short, it provides a looking glass into the existing network.”

Kitney adds that even for those customers who wish to remain with MPLS services, application visibility through SD-WAN overlay toolsets can lead to a better use of bandwidth and therefore cost savings and better application responses. “The beauty of SD-WAN is that you can pay to start with a limited feature set and switch on features and functions as you go.”  

VMB’s Conrad picks up on this theme and says because SD-WAN is a technology based in software, it’s highly malleable and customisable. “It means that we can take a customer’s requirements and develop an SD-WAN solution that works for them and their needs, and this translates in to being able to serve all parts of the market. That said, migrating between IT systems and network infrastructure is a journey, and that’s something firms should think seriously about before deciding to go ahead and make a big change.”

And change is apparently inevitable for any company that seeks longevity.

“To put it bluntly, businesses won’t survive for very long without embracing digital transformation,” warns Zscaler’s Yogi Chandiramani. “SD-WAN enables this transition securely and cost-effectively.”

Chandiramani explains that the concept of backhauling traffic to a centralised data centre worked when applications and users resided there. But with users in branch offices and applications moving to the cloud, he believes backhauling traffic across a hub-and-spoke network provides a “poor” user experience that is expensive and increases security risk. 

“Companies are paying to backhaul traffic to bring remote users onto a network that they don’t need to access,” says Chandiramani. “To overcome these challenges and deliver a fast user experience, traffic needs to be routed directly to the internet. Once businesses understand this, SD-WAN is the only viable option.”

When to change

Aryaka’s McEwan says that the top factors that drive IT leaders to adopt SD-WAN include cloud adoption and readiness, application performance needs, cost and complexity reduction motives, need for agility, and service level improvements. He adds that security and regulatory compliance requirements are also critical factors that influence the decision to migrate: “It’s essential that business-critical application traffic isn’t exposed to the public internet and doesn’t have entry points that can be exploited by threat actors.”

For Foster, a telco service renewal or the need to increase capacity is a good time to consider adopting SD-WAN. He says the need to access cloud services or when experiencing performance issues after migrating to SaaS can also be a catalyst to consider using the technology. 

Armstrong reckons organisations will reach a point where they realise that their standard MPLS or DSL connectivity is not going to support their business transformation programme or plans for digitisation. She says: “They cannot enhance the customer experience by tweaking their current networks and realise they must look for a more advanced solution that takes them up several levels of operational agility and efficiency.” 

Atchison Fraser, global head of marketing for Talari Networks, is likely to support this view when he says: “We’re in a digital age, driven by a digital economy led by born-digital companies. For organisations and enterprises to deftly manoeuvre and succeed in this new era, they need to implement a pervasive digital transformation strategy across every edge of the network. 

“The impact of digital transformation on the WAN will potentially be much more extreme. Merely adding more bandwidth to the last-mile network or throttling bandwidth usage are not viable options alone in a successful digital journey.”

Many industry experts, especially those with a background in WAN optimisation, have long held the belief that if your network traffic is suffering from bottlenecks, latency, or any other gremlin, throwing more bandwidth at the problem is not the solution. 

Axians’ Gilmour says: “A lot of IT managers have very little control and visibility over their networks currently – you tend to receive a report at the end of the month setting out how much bandwidth you’ve used, possibly along with the top applications you’ve used etc., but this is retrospective and doesn’t give much insight into tuning your network as you go.”

Citing research from a survey conducted by Axians’ last year, Gilmour says 44 per cent of network managers reported customers complaints about slow application performance happening at least once a week. “SD-WAN works in conjunction with next-generation applications to help them operate properly, so that the business receives the full benefit of adopting those applications in the first place.

enables reporting that tracks and analyses end-to-end application performance in real time, so the network can quickly react to any changes.”

So far, and as with all IT innovations that tend to hog the headlines and dominate industry discussions, SD-WAN sounds like the sort of tech that can leap tall buildings and save the planet. But of course it is not the panacea to all your networking woes, and there are certainly pitfalls to avoid when looking for a platform.

How to choose a platform

An SD-WAN solution will need to integrate into the traditional data centre and branch networks, which means support for technical features such as network routing are key, says Foster.

“Also think about the future – a network manager shouldn’t just focus on the WAN as a collection of wired and wireless services. The WAN could also extend into the branch, so a software defined infrastructure (LAN and WLAN) then becomes part of the solution.”

Foster goes on to caution that not all SD-WAN platforms are equal, so network managers also need to look out for other characteristics: “Embedded services such as path quality, WAN optimisation and network and application visibility are key parts of a fully integrated SD-WAN solution and should be on the list of selection criteria for a network manager. Open APIs to the SD-WAN orchestration platform mean that software and application development teams can now orchestrate their own cloud connectivity, bringing the network into the continuous development cycle, rather than being an afterthought. In order to successfully integrate into existing networks, preventing the need for a complete ‘big bang’ replacement, an SD-WAN solution also needs to have the routing technology within the solution.”

Aryaka’s McEwan also points out that not all SD-WAN platforms are equal, adding that the technology is more complex than just a “software-defined on-ramp to a private network”. 

“It comprises both hardware and software, and the methods in which it is delivered – and by which it performs – differ with each SD-WAN provider. It’s critical for potential buyers to understand the core differences.” 

According to McEwan, network managers should ask the following four questions before deciding on an SD-WAN provider to meet business connectivity needs.

Firstly, do they need an SD-WAN with a network or just a routing device at the edge? Internet-based SD-WANs reduce costs and complexity at branch offices, and also provide better application control. But while this works well for businesses with multiple offices in a single geographical location, McEwan warns that global enterprises with offices in multiple continents or separated by large distances will have trouble with application performance due to high latency and the variability of connections. Furthermore, responsibility for building and managing the network around the globe will fall to the IT team.

McEwan explains that a global SD-WAN service provides an integrated solution focused on application delivery and not on buying separate components. “The service embeds SD-WAN functionality into a cloud-native private network, and has redundancy built in. This saves costs compared to the approach of having dual MPLS links or a combination of MPLS and internet. It also provides an optimised network for faster application performance from anywhere in the world.”

Secondly, network managers must consider whether they need to address connectivity for regional or global deployments. If all branch offices are within a local area, and the internet quality is extremely high, then McEwan says an internet-based SD-WAN deployment might be sufficient for the organisation’s needs. 

“With an internet-based deployment, a business can reduce network cost and complexity by replacing regional MPLS links with broadband. However, by using the internet as your WAN backbone, you cannot address global application performance issues. This is because the internet is plagued with unreliable latencies and congestion-based packet loss and these issues are aggravated over large distances. For global SD-WAN deployments, you need to leverage a private network to improve data and application performance.”

Thirdly, if the majority of the organisation’s applications are on-premises and hosted close to end-users, internet-based SD-WANs can address the organisation’s connectivity requirements. However, for accessing cloud and SaaS applications over long distances, McEwan says there are not many viable WAN solutions. “Accessing cloud services and SaaS applications over the congested public internet can be unreliable and slow, due to heavy packet loss and fluctuating latencies. Internet-based SD-WANs cannot address this issue, as they too rely on the vagaries of the public internet.”

Fourthly, network managers must ask themselves if they want to manage their SD-WAN in-house or have it delivered ‘as-a-service’. 

“As businesses scale (especially worldwide), they can find themselves dealing with multiple providers managing tens of ISP or MPLS contracts. Furthermore, SD-WAN integration can become a hassle, especially when mergers and acquisitions take place and you have a variety of disparate networks to either combine or manage. 

“With an as-a-service model, enterprises can consume their network the same way they as they would applications like Salesforce or cloud services such as AWS. All the WAN management is taken care of by the provider.”

As another managed services provider, OBS’ Kitney says it’s important to bear in mind that there are different types of SD-WAN implementation: “There’s the standalone option where the provider will sell you the box and the customer does the rest. The risk here is that a specialist SD-WAN standalone solution could mean that you’re locked into that solution. Furthermore, there is still a level of complexity to manage, and separating the control function from the underlying transport leads to complexity and difficulty in managing the end-to-end estate.” 

Kitney confesses to being a “proponent of choice” where users have the flexibility to consume different services as and when they want to because they haven’t already invested heavily into the hardware. As a result, he believes that the “compelling option” when it comes to SD-WAN is to work with someone who can provide an end-to-end experience that is covered by a SLA throughout and with quality of service maintained across all elements of the network. 

“The future roadmap is key as well. Make sure any provider you choose is able to show you how they will deliver virtualised networking technologies that will help your business in years to come. For example, full automation, NFV and SDN are considerations for the future. Businesses should avoid being stuck in a cul-de-sac of technology”

Talari’s Fraser continues in a similar vein when he says network administrators can narrow their choice of vendors based on the delivery or consumption models on offer. “For example, many SD-WAN vendors are focused on the needs of carriers, which means that the enterprise customer may be locked into a single source carrier for circuits and WAN services. Telcos selling SD-WAN hybrid services are primarily trying to lock customers into long-term, expensive MPLS contracts.”

Hughes warns that one of the key things network managers should avoid, unless they know what they are doing, are zero-touch solutions. “SD-WAN is a technology that is easy, but only if you already know how to do it,” says Armstrong. “The management side is important because although an organisation can adopt a DIY approach, it is very easy to get it wrong. Organisations can end up with a provider who manages the software and little else, which is not a complete solution.”

A life less complicated

Does the network manager’s role change when it comes to running a WAN based on software rather than on-premise infrastructure? If there is one thing that unites all of the companies that we spoke to here, it is the belief that SD-WAN makes working life easier for the network manager.

For instance, Armstrong says: “Instead of managing the performance of 10,000 boxes, everything can be orchestrated from one point of control with huge gains in network visibility. That leaves ample time for managing new initiatives for the organisation or business, as well as strategic planning.”

Talari’s Fraser agrees that SD-WAN enables network managers to transition out of “firefight mode” and actually sleep easier at night, while Foster says the benefits of network management simplicity provided by the technology can’t be overlooked. “By reducing the complexity and speed at which changes can be made, the mundane tasks of the network manager can be removed and the time that used to be needed planning for and testing network changes can be used to become innovative and add value to the business.” 

But while the technology promises simplification of network orchestration, Foster points out that there’s still a need to integrate a solution into any existing infrastructure. “So the skills and knowledge of a network manager in technologies such as routing protocols will be required to establish and maintain an interface between the SD-WAN and existing in-house infrastructure.

As with any new technology, Foster goes on to state that there will be some training required in order to learn how to integrate SD-WAN management processes and procedures into existing network management practices. But unlike legacy networking technology, he says there’s no need to learn complex CLI commands or to construct offline configurations to then ‘upload and hope”. Instead, Foster says the orchestration platform’s intuitive GUI can be used to pre-build device configurations policies ready to be committed. Furthermore, the systems themselves can have failsafe mechanisms to prevent misconfiguration. 

“Learning to use the integrated wider capabilities, such as software defined wireless and LAN for branch networking or WAN optimisation may be a new concept to some network managers, but once again, the GUI orchestration simplifies the adoption of these technologies.”

Armstrong also says the operation of SD-WAN requires the acquisition of new skills, working with a new interface, and managing the rollout. She says migrating to a platform may also include more involvement in managing suppliers which can be complex and time-consuming if the technology is not being supplied on a full managed services basis. 

The future 

According to Axians’ Gilmour, SD-WAN is now on most enterprise CIO's radar and the early adopters are already in progress or completing their own projects with this technology. But he adds that the main issue he can see slowing down this adoption is that many enterprises have previously outsourced their networks to a managed MPLS provider. “Although the adoption of SD-WAN allows the IT manager to take back control of their network, many either do not have the skills or resource to do this, and so are looking for the managed service providers to catch up with the rest of the market and offer a portfolio of SD-WAN services as a managed service.”

Gilmour reckons that, in general, these providers are still trying to find their feet with the technology and then, once they have chosen the right technologies, build next-gen services around them. “So there is a bit of a lag with customer demand that is slowing the adoption rates currently.”

In the meantime, other vendors are identifying what the foreseeable future of SD-WAN could look like. For example, McEwan says major developments will include a continued industry shift form an appliance-only model towards managed services, with a particular premium on those vendors that can virtualise the WAN end-to-end, rather than relying on non-managed Internet backbone links.

He also predicts that SaaS-first enterprise initiatives will accelerate SD-WAN adoption, more global enterprises will recognise that deploying SD-WAN over the internet will not address underlying application performance issues, and that remote and mobile workers and the IoT will the fuel the adoption of SD-WAN solutions.

Furthermore, SD-WAN tools will start to adopt machine learning and AI capabilities to take networks to the next level. “The potential is there to predict network behaviour in real time and route traffic over the best path, as well as using machine learning algorithms to identify network issues before the customer even experiences them,” says McEwan.

Riverbed’s Foster support this view, He says AI’s integration into SD-WAN makes changing the network to resolve business and IT challenges an automated process, and means the network can be adapted on demand. “Using the APIs to allow orchestration of network connectivity and integration into continuous application evolution means that when new cloud resources or connections to third party services are required for data sharing, access to it can be done without manual intervention. 

Foster also believes that SD-WAN is at the forefront of ‘white-box’ edge networking. He says this will continue with x86 platforms overtaking legacy routing hardware at the WAN edge, all managed and orchestrated using SD-WAN management platforms. 

Furthermore, Foster believes that tighter integration with end-user experience management will be led by SD-WAN, resulting in the ability to alter network behaviour to suit the requirements of user experience or application performance, in real-time, to suit business cycles or priorities. “Extracting performance metrics from the WAN and feeding IT and business performance tools will make SD-WAN a strategic platform, not just a transport mechanism.”