Designing More Intelligent Data Network Solutions: Top Tips for Building an SD-WAN that Works

For a majority of our managed services customers, and in fact, for most organizations today, the journey to the cloud is already well underway. 

This is changing how we build data networks and what we need from our infrastructures, so it’s no surprise that interest in technologies that promise to improve data transfer speeds, application performance, and user experience in today’s hybrid and cloud-first IT environments continues to grow.

Software-defined wide area networking (SD-WAN) is one of these technologies, and our customers ask about it often—for very good reasons. SD-WAN meets a number of emerging business needs. Implementing it can improve connectivity over enterprise networks and can link branch offices and remote sites with corporate headquarters and cloud data centers more intelligently, affordably, and securely than legacy WAN connections could.

SD-WAN Basics: What It Is and When to Use It

Essentially, in SD-WAN, software performs functions like network traffic management and monitoring that were traditionally accomplished by specialized hardware equipment. SD-WAN is a data network solution that makes it easier to control and manage traffic flows since it enables multiple segments to be administered from a common interface. It provides a dynamic routing protocol for customer applications and the traffic they generate. This means that it can automatically find the best path for your data to travel as it crosses the Internet, cloud-native private networks, or existing WAN circuits.

When our customers make the move to the cloud, they’re transitioning from relying on private circuits to leveraging public ones. SD-WAN is a tool that helps them maximize the value of this new shared infrastructure as they make the switch. Ken Beck, Solutions Architect, VectorUSA

One of the most attractive features of SD-WAN technology is that it enables organizations to maximize the health and performance of their existing circuits. By so doing, it also allows them to maximize the value they gain from previous investments in infrastructure and hardware.

SD-WAN accomplishes this using intelligent, centralized, programmable traffic controls. Conventional routers and switches direct data packets according to a first-in, first-out (FIFO) protocol, in which traffic is simply sent to the appropriate TCP/IP address in the order that it was received by the routing device. In this model, backup circuits are only used when the primary circuits begin to approach full capacity. They remain idle at all other times.

With SD-WAN, traffic is instead directed in accordance with business needs. Its intelligent routing policies allow customers to take advantage of all their circuits, including broadband Internet, 4G wireless, Multi-Protocol Label Switching (MPLS) pathways. And they can be set to prioritize traffic from business-critical applications, or establish policies that ensure that bandwidth-consumption, latency, jitter-reduction and packet loss requirements will be met.

SD-WAN is appropriate in a wide variety of scenarios and use cases. Trying to connect multiple branch offices to a central headquarters location? SD-WAN can improve security and network performance. Want to enable connectivity to corporate resources hosted outside the network perimeter? SD-WAN will ease configuration, administration, and security challenges. In fact, the only time it might not make sense to consider SD-WAN is when your organization has only a single office location and very simple network infrastructure.

If you’re considering building a new SD-WAN deployment, here are our top three tips for working with data networking companies to ensure superior performance and reasonable costs.

Tip #1: SD-WAN works best when partnered with LAN-side Quality of Service (QoS) in a comprehensive data network solution.

QoS technologies manage traffic and establish routing priorities to reduce packet loss, latency, and jitter for applications whose performance is sensitive to these kinds of disruptions. Such applications include streaming video and Voice over Internet Protocol (VOIP). A common misconception is that SD-WAN provides all the QoS guarantee you’ll need. But in fact, SD-WAN performs QoS only across wide-area networks. If you want intelligent routing of services and a guarantee that your data will travel along the best possible path, you’ll get this with SD-WAN. QoS provides an additional assurance: that those data packets will be ordered so as to guarantee optimal application performance. For instance, the large data packets generated by the backup of your central sales database won’t get in the way of small voice packets that must travel quickly if your VOIP calls are to maintain optimal quality.

Tip #2: To optimize SD-WAN performance, your circuits need to be as similar as possible.

Although SD-WAN is designed to maximize the performance of existing infrastructures, there are practical limitations on the composition of these infrastructures. If, for example, you have a primary circuit with a 500 Mbps capacity and a backup circuit with a 10Mbps capacity, the disparity in bandwidth between the two is simply too great to enable that backup circuit to work well in an SD-WAN. In today’s networks, if one circuit reaches 70 to 80 percent utilization, traffic needs to be rerouted to another circuit of similar bandwidth in order for acceptable performance to be maintained. Understanding these infrastructure constraints can help you decide when it might make sense to upgrade bandwidth and infrastructure. Ultimately, inadequate or outdated circuits can cost your organization a great deal in terms of lost productivity.

When your end users aren’t able to get their work done with the existing bandwidth, the initial cost of an upgrade will be more than repaid in terms of increased effectiveness and productivity. Imagine how many more deals your sales team could close if the CRM system’s performance was excellent, and you’ll see that sometimes you can’t afford not to do it. Ken Beck, Solutions Architect, VectorUSA

#3: Traffic studies are an essential part of building the policies that will allow your SD-WAN to perform its best.

SD-WAN isn’t a standalone technology that you simply purchase, configure, and implement. How well your SD-WAN performs is directly related to how well the traffic policies you define reflect your organization’s operational processes and workflows.

To maximize the value of an SD-WAN deployment, we always need to identify how our customers’ employees accomplish their work, and what they need to get their jobs done. Ken Beck, Solutions Architect, VectorUSA

Not all Internet circuits are created equal, and an essential part of the traffic study involves analyzing whether yours will meet your requirements. We also examine which applications your employees use most often, and how they use them. A traffic study lets us make rigorous, evidence-based recommendations about which infrastructure upgrades are essential, and which traffic policies will work best. The takeaway: SD-WAN solutions can give today’s organizations the tools and capabilities they need to make best possible use of their existing connectivity infrastructures—and be cloud-ready for the future.