This talk takes a look at the history of SDN control at a major service provider. From the early pioneering and implementation of Intelligent Route Service Control Point (IRSCP) technology to applications on today’s D2 network for SDN control of Layers 0-7. In 2004, we implemented one of the first version of IRSCP at scale in our network. As we deepen and grow that early commitment to SDN, we like OpenDaylight for the breadth of brownfield protocols that are supported, its model driven approach that matches our service abstraction logic, and the ability to add applications on top of the controller base. In our experience, model driven is the best practice to enable the kind of scale and feature velocity required for the layers of the global network.