SD-WAN Double Take: A View of the Underlay in the Evolution of Software-enabled Connectivity

As the Software-Defined Wide Area Network (SD-WAN) market continues to evolve, the challenge is in getting a truly synchronized view on the direction it is heading. If you ask a half dozen CIOs where SD-WAN will land in the next 2-3 years you are likely to get six different perspectives. Yet, the jury is in; SD-WAN is the way of the future.

Over the past 12 months, there has been a noticeable increase in deployment of SD-WAN, fuelled by the demands to drive efficiency, security and cost savings. The enterprise user’s experience is now defined by high-performing applications, reliable connectivity and instant access to Cloud services. In other words, software-enabled networking is rapidly evolving and transforming how users connect to the Cloud.
The Connection Factor
With strategic directions crossing different paths, a shakeout is expected. Some SD-WAN vendors are going down the route of proprietary appliances running their own dedicated Virtualized Network Functions (VNFs), while others are betting on more open-source technology and neutral “white boxes” running a variety of vendor VNFs.
Amidst the ongoing cut and thrust of innovation, product releases and analyst reviews, one fact remains constant: SD-WAN technology allows for the increased use of low-cost Internet in enterprise Wide Area Networks.

As SD-WAN technology becomes more widely available, functionality gaps continue to exist, which make the choice of Internet circuit even more critical.

On the surface, this brings a wealth of potential benefits to the global CIO, ranging from lower network running costs to “a bigger bandwidth bang for the buck.” But are we guilty of taking things for granted? Is the widespread use of low-cost Internet in the enterprise WAN as straightforward as it sounds?

Under the “right” circumstances, low-cost Internet is the ideal network access mechanism. The key here is “under the right circumstances.” In other words, there is no escaping the fact that over a period of time, the Internet, and especially broadband technology like xDSL, is not as reliable as other connectivity types. Experience shows network faults occur up to 4 or 5 times more on broadband Internet circuits than on more recognizable “enterprise grade” connectivity like Ethernet or MPLS.

According to Steven Weingartner, Infrastructure & Communications Manager at P&O Maritime, “We had local Internet services running IPSec tunnels from out of Europe, Africa, and the Americas. It became unbearable to deal with multiple local ISPs and trying to use their unreliable Internet services with ever increasing latencies.”

The real key to success is, therefore, in choosing the right option, and then operating it successfully in partnership with the Internet Service Providers (ISP) providing the connection.

Back to the Basics

Estimates show the existence of more than 10,000 ISPs globally. In tightly regulated markets in countries across Africa and the Middle East for example, this typically means one, or maybe two, providers to choose from. But in most countries the choice of provider is plentiful.

Breaking things down further, each ISP offers a whole catalog of product options and deals, often based on a range of access media; ADSL, SDSL, VDSL, HDSL, Ethernet, 3G / 4G, LTE, WiMax, Satellite, FttH, FttC, etc. Yes, there are literally hundreds of thousands of Internet options to choose from around the world!

These choices can be bewildering, and to make matters worse, the choices alter with alarming regularity as ISPs release new offers and change their product mix often to stay ahead of the competition.

As a starting point, some targeted “googling” should reveal insights into which ISPs have a strong track record of delivery and reputation, and which don’t.

Sifting Through Choices

“A number of technical features and variables need to be taken into consideration when beginning to choose a low-cost Internet circuit appropriate for an enterprise SD-WAN deployment,” said Braham Singh, Senior Vice President, Global Product Management, RCOM/GCX. “The most obvious of these is the bandwidth required to support the users at a site, taking account of how much application traffic is destined for the Cloud with more and more enterprises moving away from on-premise data centers. But often even that may not be necessarily straightforward, with user activity and traffic flow key factors, and “download” / “upload” speeds varying according to whether an Internet connection is synchronous or asynchronous.”

Next, there is the question of “contention ratios” – essentially the level to which the ISP oversubscribes its network capacity. CIOs are all-too-familiar with “the Internet going slow” which often happens when Internet activity (for example with streamed video, or online gaming, etc.) drastically ramps up aggregated traffic across an ISP’s core network, with individual circuit performance plummeting. The higher the contention ratio, the more exposed to this variation on performance a connection is.

Most ISPs also differentiate their offerings by “residential” or “business” with products sold as residential typically lower cost and with contention ratios higher than their business equivalents. Yet even a “business” Internet circuit, with high top-end bandwidth and low contention levels, may perform badly if the ISP’s “backbone” network is less well connected to the rest of the Internet (via Internet peering and interconnects) than the competition. Without realizing it, a user in the US may find their Europe-bound network traffic taking an inefficient, circuitous path across the Pacific to Asia and back en route to the server they are trying to access. Latency really can be the silent app killer.

And with most SD-WAN vendors offering “link-bonding” of multiple broadband circuits to create a pool of usable bandwidth, it makes sense for businesses to try to use different ISPs for a little resilience when connecting a location. However, only after a lot of research and probing will the truth be revealed on “Local Loop Unbundling” and whether separate access infrastructure is available across two or more ISPs at a site.

Technical Stepping Stones and Gaps

As SD-WAN technology becomes more widely available, functionality gaps continue to exist, which make the choice of Internet circuit even more critical.

For example, not all SD-WAN vendor platforms today support all traditional circuit interfaces like RJ11 or E1/T1, or can work seamlessly with 3G/4G Internet services without the addition of an external modem (which in turn contradicts the whole “lower TCO through reduction of appliances” message).

And while SD-WAN allows for the lowering of network running costs, there are other issues that must be considered including management of the “last mile” which was much more straightforward; almost a given in the traditional MPLS world.

In a nutshell, making a choice of which low-cost Internet circuit from what ISP may not be straightforward. The devil really can be in the details.

But while the SD-WAN technology at the network edge is new to almost everyone, the Hybrid Internet underlay that holds the network together is “business as usual” for some expert providers.

An Unrivalled Pedigree in Internet Hybrid WAN

SD-WAN using Hybrid WAN might still be emerging, but for Global Cloud Xchange (GCX), it is simply an evolution of an approach that goes back many years. The company has deployed well over 500 such Hybrid Internet-based WANs over the past two decades using connectivity like broadband Internet, satellite, 4G and more. And over that time, GCX has built up a track record and pedigree of delivering business-critical Hybrid Internet networks for large multinational enterprises second to none.

“With customer locations under management and connectivity provided in more than 160 countries worldwide, we have solved almost every conceivable problem when it comes to providing a Hybrid underlay. Ours is not experience built over a period of months or even a handful of years, but instead from 20 years of providing Hybrid networks for airlines, for retailers, for manufacturers, for logistics providers,” said Mark Russell, Managing Director, GCX International.

According to Singh, “Hybrid Internet is the underlay of choice for GCX, around which our managed services are built. We have management platforms, systems, processes, supply chains and technical expertise crafted over almost two decades which enable us to tackle all the issues associated with Hybrid WAN head on.”

“With the new GCX WAN we have a fast (low latency), reliable and secure fully managed Global WAN, and it is doing everything GCX said it would and more,” added Weingartner of P&O Maritime.

The GCX Track Record
Harnessing the Hybrid Underlay

If SD-WAN is the future, CIOs must understand the underlay network. While there is a role for low-cost Internet in the corporate SD-WAN, there are plenty of pitfalls and hazards waiting to trip the unsuspecting IT Manager. But this shouldn’t deter the forward-thinking enterprise. With the appropriate consideration and respect given to the underlay as to the devices and technology at the SD-WAN, the time is right for the adventurous CIO to really unleash the power of the Software-Defined WAN.


CLOUD X WAN is the complete global managed SD-WAN solution with hybrid WAN connectivity for any site, anywhere.
Click here to find out more.