Which SD-WAN?

There’s a lot of talk about SD-WAN and the benefits it can deliver. If you’re a multi-site business with growing bandwidth needs, SD-WAN enables you to manage bandwidth more efficiently across all your locations. By decoupling the networking hardware from its control mechanism—that’s the SD, or software-defined piece of the acronym—SD-WAN simplifies the management and operation of your WAN and enables you to dynamically share bandwidth across your connection points and centralize policy management and security.

SD-WAN 101

In the simplest terms, here’s how SD-WAN works. First, it identifies and classifies the application traffic being sent. Then, it checks circuit performance and matches it to the application SLAs. Finally, it selects the path and transmits the traffic. Let’s say Internet path A is experiencing high latency and packet loss, which is not ideal for real-time applications such as voice or video. (How annoying—not to mention time-wasting—is it to get your entire team, or worse your customer, on a conference call and have it drop because of a connectivity blip?) The SD-WAN appliance will move the critical traffic over to path B, then once path A is restored, move it back.

But did you know there are different types of SD-WAN? In all SD-WAN scenarios, each location will have an SD-WAN appliance, also called an SD-WAN edge device, and you manage the SD-WAN policies. The different options relate to the SD-WAN controller, which is the device that manages the traffic flows. There’s on-premise controller, cloud controller, and gateway controller. If you’re thinking about SD-WAN for your organization—whether you’re considering replacing MPLS connectivity with SD-WAN or want to take a hybrid approach—you need to understand the differences.

On-Premise SD-WAN Controller

In this architecture, as the name implies, you install the SD-WAN controller on premises to perform traffic shaping in real time. The controller is only connected to your company’s other sites, making it a highly secure option. And it gives you control, but you have to maintain the controller environment, including the storage, VM, etc. And if you want high availability for the controller, it can be complex to set up in an on-prem scenario. This might be an appropriate option if your company hosts all applications on-prem—no cloud deployments—and you have the IT resources to manage it.

Cloud SD-WAN Controller

In this scenario, the controller is hosted by the SD-WAN supplier, simplifying maintenance for your team. Just like with on-prem, branch-to-branch communication happens at your main site, but this option delivers high availability and increased reliability and performance of your cloud applications.

Gateway SD-WAN Controller

In this option, a virtual SD-WAN gateway sits outside your main site in a cloud environment, which means branch-to-branch communication happens in the cloud, easing the traffic on your main site’s networks. Additionally, the gateway can have multiple connections for different transports—Internet, MPLS, LTE, etc.—to support a hybrid WAN that spans a diverse communications infrastructure.

The Right SD-WAN Solution for You

If you’re still not sure which SD-WAN approach is best for your company, BCM One can help. We’re SD-WAN agnostic so our priority is meeting your needs, not pushing a specific technology. And we’ve carefully vetted and have strategic partnerships with various SD-WAN providers across all three different types to accommodate different business and technical requirements. Contact us to learn more.