Gartner recommend that you look at SD-WAN when refreshing your WAN edge equipment, renegotiating a carrier contract, building out new branches, or aggressively moving apps to the cloud (among other reasons).

SD-WAN has several very real and tangible benefits (cost, performance, availability to name a few) with clear ROI when compared to alternatives. In fact, this is what is driving rapid adoption. However, one question that often comes up with clients is “what are the downsides” or “it sounds to good too be true”. With that as the backdrop, here are some of the downsides (or “challenges” as the marketers call them) affiliated with early SD-WAN deployments…

• Substantial functionality gaps exist with many well-known SD-WAN vendors/products. For example, features that are missing from many SD-WAN products include T1/E1 interfaces, integrated 4G/LTE capability, WAN optimisation, and even support for IPv6. This will change and vendors are adding these capabilities as we speak, but at this point in time, most vendors don’t have them all.
• SD WAN can facilitate a move towards lower-cost Internet transport, but this can lead to challenges in managing heterogeneous connectivity. MPLS did something that everyone knows about, but that most people don’t really appreciate – manage that last mile. I’ve talked to many SD WAN early adopters that started bringing in lots of Internet connections only to find that the heterogeneous nature of vendor and/or service offerings prompted them to bring in a third party aggregator to manage it, or go with a higher cost provider with a larger footprint.
• Despite the name, there’s a good bit of hardware involved as most SD WAN vendors lead with hardware appliances in accounts.
• While SD WAN is much easier to configure and operate than traditional routers (probably 10X when making complex application routing policy), many SD-WAN implementations have actually added technical debt to the branch.
• This is because many of the early adopters are not actually replacing an existing router (at least not yet) for a variety of reasons including aversion to risk, lack of functionality, etc. Instead they are placing it behind and/or in conjunction with the existing router. I anticipate this will (and should) change soon.

Many of the issues raised above have already been encountered and dealt with by Onwave as we have been deploying SD-WAN solutions for over 5 years. The main recommendation we can make to you if you are looking into an SD-WAN solution is to use a manufacturer who has Multi-WAN routers, these by default accept multiple backhauls connections, xDSL, FTTC, fibre, LTE even satellite. This allows you to build in huge levels or resiliency to keep your IP Data traffic flowing even in the most catastrophic of events.

You can also engage a Managed Service Provider to give you a single bill for your WAN even if it is built out of tens of providers globally.

They will even make a change to your WAN in less than 28 days!