  The evolution of Software-Defined Networking (SDN) has so far been
predominantly geared towards defining and refining the abstractions on the
forwarding and control planes. However, despite a maturing south-bound
interface and a range of proposed network operating systems, the network
management application layer is yet to be specified and standardized. It has
currently poorly defined access control mechanisms that could be exposed to
network applications. Available mechanisms allow only rudimentary control and
lack procedures to partition resource access across multiple dimensions.
  We address this by extending the SDN north-bound interface to provide control
over shared resources to key stakeholders of network infrastructure: network
providers, operators and application developers. We introduce a taxonomy of SDN
access models, describe a comprehensive design for SDN access control and
implement the proposed solution as an extension of the ONOS network controller
intent framework.
