You can use software-defined WAN (SD-WAN) hardware and software to align to your business goals, improve resiliency, and increase agility and speed. But to realize these benefits, you'll first have to select from a diverse set of vendors that vary by size, functionality, geography, and vertical market focus. Infrastructure and operations (I&O) professionals should use this report to understand the strengths and weakness of each segment and then examine a group of vendors within a particular segment.