The document discusses disruptive changes in communications networks driven by the Internet of Things, big data, cloud computing, and the evolution of services. These "tectonic shifts" are transforming networks and driving the transition to software defined networking (SDN). SDN uses virtualization and network functions to abstract the network, enabling faster innovation, lower costs, and more flexible, software-based control of network resources. The changes present both challenges and opportunities for network operators and providers to reinvent their networks.