SDN in wide-area networks: A survey

Over the past several years, Software Defined Networking (SDN) has emerged as a new and promising paradigm for the management of computer networks. While we have seen many use-cases and deployments of SDN in data center networks, wide-area networks still heavily rely on legacy routing and traffic engineering technologies. Rapidly increasing traffic demands (mainly due to increasing usage of video streaming and voice over LTE deployments), however, motivate the development of novel routing and more efficient traffic engineering mechanisms. New approaches leveraging an SDN paradigm in wide-area networks promise to mitigate many of today's limitations, inefficiencies, and scalability issues. In this paper, we give an overview of the current state of the art in Software Defined wide-area networking research and technologies and give directions and discuss ideas for future work.