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SD-WAN is on the rise: How to make that first step

The Wide Area Network (WAN) has not seen much in the way of innovation for the better part of a decade. While the rest of the infrastructure has become more agile and fine-tuned for the cloud and a virtual world, the WAN continues to be constrained to the high costs and inflexibility of multi-protocol label switching (MPLS) networks. The WAN has always been about connecting users to applications. MPLS makes sense for the WAN when those applications are in the data centre.

However, now that more and more applications are moving to the cloud, which MPLS is not designed for, users are left with cloud applications that perform better when accessed via the internet from home than over MPLS from work. It causes IT organisations to become increasingly frustrated with the rigidity, cost and complexity of today’s MPLS-based WAN. These challenges of traditional WAN architectures has led to an industry movement that allows enterprises to simultaneously leverage multiple types of connectivity, particularly broadband, in a secured and optimised way – this is often referred to as the Software-Defined WAN (SD-WAN).

The rise of SD-WAN

With today’s reality of cloud-based applications and MPLS no longer being sufficient enough to address today’s WAN requirements, it comes as little surprise that there is an industry movement afoot towards the SD-WAN. It’s why IDC predicts that the SD-WAN market will grow to become a $6bn (£4.2bn) industry by 2020 - growing at a more than 90 per cent compound annual growth rate for the next five years.

With more applications offered on-demand via the internet and cloud, there is a distinct need for enterprises to operate at 'cloud speed'. Gartner predicts that by 2018, Software-as-a-Service (SaaS) will become the dominant model for consuming application functionality for approximately 80 percent of all organisations. To operate at this pace, organisations now face a number of challenges, which include improving the responsiveness and agility of the business and the network, while also reducing costs and providing better performance for cloud applications.

In the new cloud-driven world, there is an overarching need for increased responsiveness and agility. If a new office needs to be opened, an existing office needs to be relocated, or if IT resources need to be moved, the process to add, move, or change MPLS connectivity takes too long and is too disruptive to the business. For example, establishing connectivity at a new site, or increasing the bandwidth to an existing one, can take up to a month or longer. To compound matters, MPLS does not accommodate new methods of automation, and typically requires on-site IT expertise and configuration of networking equipment. Lower-cost internet connectivity is available, but it has lacked scale, reliability, and security. If internet connectivity is part of a WAN architecture, it often sits idle until needed for fail-over. This is like buying a plane ticket from London to Scotland, and also buying a non-refundable bus ticket in case the flight gets cancelled.

Today, we directly access cloud applications in our homes via broadband internet, which works just fine and costs less. However, accessing those same cloud applications from within the enterprise can often result in slower performance for cloud applications, not to mention wasted costs for the business as a result of the transmission being sent back over the expensive MPLS connection. This begs the question, why not connect users in a branch directly to the cloud over the internet?

As more and more SaaS is being used within the enterprise, IT teams also are increasingly losing visibility and control over this expanding mix of applications. Most CIOs and IT leaders today cannot say how many SaaS applications are running on their network, or which SaaS applications are in use across the enterprise. When SaaS performance or connectivity problems arise, organisations are usually notified via IT trouble tickets. As a result, the IT team not only needs to improve the performance of this new set of applications to keep cloud users happy, but they also need to rein in how applications are being used on the network.

Making that critical first step

When implemented correctly, an SD-WAN can help enterprises flexibly and securely connect users to applications by the most cost-effective source of connectivity available. This enables enterprises to augment or replace MPLS networks with secure broadband internet connectivity. An SD-WAN supports multiple paths and allows connectivity decisions to be made independent of carriers, which helps enterprises avoid lengthy procurement and deployment delays for a faster time to service at the branch. Once connected, an SD-WAN fabric should provide visibility into both datacentre and cloud traffic, and provide the ability to centrally assign business intent policies to secure and control the WAN traffic. It should dynamically select the best path – whether that’s MPLS or broadband – for each application based on customer-defined policies and real-time network quality measurements, all while keeping the data in-flight encrypted edge-to-edge.

An SD-WAN also should ensure private line performance over the internet by overcoming quality problems created by packet loss and out-of-order packets. This is especially important for cloud users and those that are increasingly using SaaS applications in the branch. And, for those applications that need improved performance over distance, adding acceleration and optimisation techniques should not add layers of complexity.

By transitioning to the right SD-WAN solution, enterprises can reduce their dependency on and expense of MPLS connectivity without compromising performance or security. In addition, organisations do not have to overhaul any existing WAN investments; they can easily mix and match carriers by access technology and by geography.

Move at your own pace

Moving to a broadband WAN is not an all-or-nothing approach. Enterprises can move at their own pace. While the ultimate goal may be a 100 per cent broadband WAN, enterprises can take the first step by deploying a hybrid WAN. As MPLS upgrades arise, businesses can explore lower-cost broadband internet services as an alternative path for connecting to cloud applications. This provides an opportunity to downsize the MPLS bandwidth and only use that connectivity for the remaining datacentre applications. Enterprises can then begin to migrate additional applications from the datacentre and into the cloud as desired, and do so in an optimal way.

The SD-WAN rewards

Ultimately, the benefits of transitioning to an SD-WAN model are fourfold; increased flexibility, more visibility and control, optimal performance and reduced connectivity, equipment and administration costs. Indeed, given the current industry averages for bandwidth costs, the payback for an SD-WAN investment will start immediately. With this in mind, companies should consider moving to an SD-WAN now, especially since it’s tipped to be the enterprise norm in the future.

John Vincenzo, senior vice president, chief marketing officer at Silver Peak