What is the role of northbound APIs in an SDN environment?
The northbound application programming interface (API) on an SDN controller enables applications and orchestration systems to program the network and request services from it. Northbound APIs can enable network functions like path computation, loop avoidance, routing and security. For example, northbound APIs enable orchestration systems like OpenStack Quantum or VMware vCloud Director to manage network services in a cloud.
Because SDN is relatively new, the industry is still evaluating the capabilities of northbound APIs. The northbound API for SDN environments is not standardized at this time. The Open Networking Foundation (ONF) is investigating the current catalogue of northbound APIs with the hope of potential standardization in the future.
Vendor-specific implementations of SDN architectures like Cisco Open Network Environment (ONE) use non-standard northbound APIs to provide network traffic flow information to their network management systems. As it has often happened with other emerging technologies, it is likely that market success of specific SDN architectures will decide which northbound APIs will become de facto standards.
This was first published in March 2013