This guide will provide you with a comprehensive overview of what an SD-WAN is, the benefits it can provide, when it is the right networking solution, and more. This guide is written for IT engineers and decision makers and assumes a basic understanding of existing network technologies and systems.
What Is an SD-WAN?
A Software-Defined Wide Area Network, or SD-WAN, has become the standard for how corporations ensure connectivity for their employees who are spread out across multiple locations. Building out a traditional Wide Area Network (WAN) requires that you have dedicated private circuits (typically based on Multiprotocol Label Switching, or MPLS) connecting to each location. Not only is this expensive, but it also restricts your options for routing traffic and managing your connectivity.
With an SD-WAN, the network can use multiple connectivity options, including broadband internet circuits, along with any MPLS or other dedicated circuits you have in place. This allows for a robust network that uses smart routing to ensure your data is always taking the fastest route based on application requirements.
The SD-WAN is also easier to manage than a traditional WAN because it can be done from one central location. You configure your application network settings, security, permissions, and other factors on a single interface and then push all the settings throughout the network. This is a major improvement over having to configure individual routers at every location.
The History Of SD-WAN
For nearly two decades, most organizations used traditional WAN infrastructure, primarily using MPLS circuits to handle the traffic. But that changed in 2013, when the ONUG board held a meeting where guests were invited to offer input and insights for technological solutions to issues that were not yet being addressed by suppliers. ONUG was founded only a year earlier to help promote standardization and observability of infrastructure technologies.
At this meeting, Jim Kyriannis, who was the Program Director for Technology Architecture at New York University, brought up what he called the “Branch Office Has Multiple Paths to Headquarters” use case. At the time, he didn’t fully realize that he was defining a challenge faced by virtually all major companies. Over time, this subject was researched further, and the title was changed to the easier to remember name, Software Defined Wide Area Network, or SD-WAN. At the following ONUG meeting, the SD-WAN concept was voted as the top issue that demanded a solution. This prompted multiple vendors and other groups to begin working on proof of concepts for the technology.
By 2014, early adopters were already implementing SD-WAN technologies. Industry publications started using the SD-WAN term consistently. Vendors developed their own SD-WAN solutions, which accelerated the adoption.
When Does an SD-WAN Make Sense?
The big question most organizations have concerning an SD-WAN is understanding when it makes sense to transition from an existing WAN infrastructure to an SD-WAN. The simple answer is that an SD-WAN will provide advantages to companies in just about every situation. It provides greater flexibility, and can be implemented in a variety of ways to meet the specific needs of a network environment.
For example, a company that currently uses MPLS connections to their remote offices can implement an SD-WAN and offload all traffic that was destined for cloud applications. This will allow them to reduce bandwidth usage on their MPLS circuits without giving up quality and stability where it is needed. Companies that eventually want to move 100% away from MPLS and use broadband internet connections for all their traffic, can use SD-WAN for a planned transition to reduce costs and avoid unnecessary downtime.