This document discusses the need for a standardized information model and high-level northbound API for SDN to abstract away the low-level details of existing protocols like OpenFlow. It proposes defining a common data-centric information model using UML that existing SDN protocols and middleware platforms can map to in order to provide interoperability and simplify development. RTI and Cisco believe this model-driven approach will help unify and evolve SDN systems to accommodate multiple protocols and legacy networks.