The software defined wide-area network (SD-WANs) has captured the attention of the global networking segment.

Value-added distributor, Networks Unlimited, has recently positioned itself in the emerging SD-WAN market as the sole distributor for Silver Peak, the global leader in broadband and hybrid WAN solutions, across the Sub-Saharan market.

"Applications are the essence of top performing organisations today. If connectivity to these applications is impaired or worse, down, business comes to an immediate halt. In addition, if an application is sluggish, it causes both user frustration and a dip in output, which has a direct effect on revenue for the business. More importantly, many business-essential applications run in the cloud and are accessed directly over the internet," says Anton Jacobsz, MD at Networks Unlimited.

Geographically distributed organisations often have hundreds or even thousands of geographically distributed branch offices connected to regional hub or headquarters' sites. For security reasons, explains Nick Applegarth, vice president, sales for EMEA at Silver Peak, cloud-based application traffic is normally backhauled from the branch across expensive WAN links to a hub site or corporate date centre, where it passes through a firewall before being handed off to the internet. Not only is this costly, but performance is often compromised due to WAN bandwidth constraints at the branch and the added latency introduced from backhauling connections. With advanced application visibility and control from Silver Peak, white-listed SaaS applications can be routed directly to the internet from any branch location, optimising performance and user productivity.

As IT organisations, divisions and service providers come under increasing pressure to balance the complexities of managing legacy infrastructure with accelerating the migration to the cloud their effectiveness can be compromised.

Some key challenges include:

1. A rigid and complex legacy WAN infrastructure increases costs and impairs productivity:
• Legacy/ traditional/ existing WAN architectures were not designed to support cloud-based applications or growing Internet traffic, impairing performance and increasing costs.
• Traditional WAN services are too rigid and it takes too long to implement changes, further stifling business agility.
2. Addressing data/ application performance and security concerns when fully embracing the Internet:
• Keeping pace with escalating demands for bandwidth even as connectivity costs continue to fall.
• Remaining fully cognisant that broadband connectivity can introduce security and performance issues.
3. Effectively managing service levels across an increasingly complicated application mix:
• Controlling data/ application and traffic flow across multiple carriers and service providers.
• Navigating an expanding combination of connectivity types/ options across the WAN.
• Leveraging existing and/or underutilised or idle broadband links.
4. Inconsistency in delivering a predictable user experience across the WAN:
• Achieving the cost efficiencies of broadband without impacting application performance.
• Selecting the right transport connectivity for the right application.

"Customers with legacy WANs are now saying ‘enough is enough'. We don't need more band-aids. We need a WAN that is optimised for the cloud that can automatically translate high-level business intent into consistent network-wide behaviour.

"Using direct internet connectivity that provides predictable performance to cloud-based applications simply makes good sense," says Applegarth.

With the push to leverage the internet to address key IT realities and challenges, the concept of an SD-WAN has rapidly emerged as the solution to explore.

Illustrating SD-WAN's phenomenal growth in the market is large research organisation, the IDC. It estimates that, worldwide, SD-WAN revenues will exceed USD6 billion in 2020 with a compound annual growth rate of more than 90 percent over the 2015-to-2020 forecast period. Benefits include: cost-effective delivery of business applications; meeting the evolving operational requirements of the modern branch site; and improving IT efficiency through automation.

IDC analysts Rohit Mehra, Brad Casemore and Nav Chander write in the March 2016 published "Cloud and drive for WAN efficiencies power move to SD-WAN" report: "SD-WAN offers compelling value for its ability to defray MPLS costs, simplify and automate WAN operations, improve application traffic management, and dynamically deliver on the cost and efficiency benefits associated with intelligent path selection."

Applegarth points out that there are key foundational components that every SD-WAN vendor must address at least at high-level. "By helping hundreds of enterprises address today's WAN challenges, we've learned that it's important to take a step back and think more holistically about the WAN. The primary thought centres on how to build a better WAN for an organisation. And that means taking into account five key aspects that any SD-WAN solution should deliver," he says.

These are:
• Performance: The ability to deliver predictable application performance and QoS across the WAN;
• Visibility: The ability to identify and control all applications and data running across the WAN;
• Security: The ability to secure all WAN traffic and applications with micro-segmentation and encrypted virtual overlays;
• Extensible: The ability to service chain and route services across the WAN; and
• Savings: The flexibility to leverage any broadband connectivity and lower costs by up to 90 percent.

In its Market Guide for Software-Defined WAN, Gartner also states that SD-WAN has four characteristics: SD-WAN must support multiple connection types, such as MPLS, Internet, LTE and more; can do dynamic path selection, that is it allows for load sharing across WAN connections; provides a simple interface for managing WAN – it must support zero-touch provisioning at a branch and should be as easy to set up as a home WiFi router; and must support VPNs as well as other third-party services, such as WAN optimisation controllers, firewalls, web gateways and more.

"It starts with the notion that not all SD-WAN solutions are created equal. Performance is arguably the most critical pillar of building a better WAN. It's not just about adding bandwidth. It's about enabling the use of multiple forms of transport and addressing issues across each connection, including – packet loss, latency, jitter, and more – to make those connections, even consumer broadband, perform like a private line. And, because more bandwidth doesn't make distance go away, many applications will still require WAN optimisation.

"It is however becoming clear a new kind of WAN is required: an SD-WAN that is automated and optimised to do the job of a cloud-driven enterprise - and looking forward, that is not just ‘software defined,' but ‘self driving," concludes Applegarth.

SD-WAN technology differentiators include dynamic path control, zero-touch provisioning, cloud intelligence and path conditioning, which ensures private-line performance over the Internet.

For more information, please contact Anton Jacobsz at anton.jacobsz@nu.co.za