CA Technologies Infinera Software Driven Networks (SDN) is an approach to networks that enables applications to converse with and manipulate the control software of network devices and resources. SDNs are comprised of applications, control software, and interfaces to services that are hosted in an overlay or logical/virtual network as well as those possibly same components that comprise the underlying physical network. Modern applications require the ability to easily interact and manipulate these resources. Applications can benefit from knowing the available resources and from requesting that the network makes the resources available in specific ways. To this end, there is a requirement to couple applications more closely to the underlying resources on which they depend, consume and interact with. SDN infrastructure and components exist in most deployed networks today. Some of these components are being standardized by various organizations, as as well some being already standardized by the IETF. However, no standards or open specifications currently exist to facilitate end-to-end operation of a software defined network, specificlly one that provides open APIs for applications to control the network services and functions offered by device control planes or other "controlling" software. The goal of this document is to outline the problem area of SDN for the IETF.