What is SD-WAN and What It Is Not

When we talk about SDN or SD-WAN, there are a few minimum requirements to qualify for the term.

• It is a network service or an overlay that is going to replace what is a more traditional type WAN service like an MPLS service. Meaning a private network provided to a person from a networking provider.

• This solution is provisioned, and you interact with it in some portal, or it could be cloud driven.

• Automatic failover. If you plug in two connections, it needs to fail-over to the other.

With these three common denominators to define SDN, you can wash out all those tricky claims many people are making about their “SDN solutions” and focus on the real solutions. It’s a hot and trendy term, so following this definition will save you a lot of frustration of wasting time with solution offers that are somewhat counterfeit or misleading.


The providers that are offering legitimate SDN solutions can provide a crucial feature as it relates to performance. For example, let’s examine a scenario where you have your two internet connections. There is an application like hosted VoIP and a low-cost bandwidth solution like cable backed up with a DSL connection. Neither of those connections is bulletproof. A key feature functionality is the ability to adapt to the performance of the environment in real time. Look at latency with the cable and DSL along with jitter and packet loss as all three affect the voice quality. Good SDN solutions will be able to take those into account in real time and adapt a voice call as it relates to the real-time performance of the network. When problematic connections arise, it could reroute to the secondary link without disrupting the call. All that without having to touch the box since it’s automated.

In a traditional router environment, you can load-balance two connections as well as automatic failover. But typically, you will do that based upon hard downs. That will require manual swapping and restarting connections which cause interruptions. SD-WAN does all that without any perceived disruptions or manual servicing.

A bonus feature is the ability to alert. Set notifications to alert about an outage and gain visibility on who is doing what within your network environment.