How are SD-WAN and software-defined networking related and/or distinct?
You can think of it as part of SDN, because there is a part of it that is about the separation of the data plane from the management and control plane. Other than that, from an architecture perspective, the business model, the business case, the reasons for deploying SD-WAN are very different from deploying SDN. That's why the pace at which it is being deployed is very fast. SD-WAN is absolutely as important as virtualization was years ago, or any one of the other trends going on, like IoT, and they're all related. You cannot distinguish SD-WAN that clearly. There's an overlap with IoT. There's an overlap with virtualization, with machine learning and AI.