A Behavior-Driven Approach to Intent Specification for Software-Defined Infrastructure Management

One of the goals of Software-Defined Networking (SDN) is to allow users to specify high-level policies into lower level network rules. Managing a network and decide what policy set is appropriate requires, however, expertise and low level know-how. An emerging SDN paradigm is to allow higher-level network level decisions wishes in the form of "intents". Despite its importance in simplifying network management, intent specification is not yet standardized. In this work, we propose a northbound interface (NBI) for intent declaration, based on Behavior-Driven Development. In our approach, intents are specified in plain English and translated by our system into pre-compiled network policies, that are in turn, converted into low-level rules by the software-defined infrastructure e.g. an SDN controller. We demonstrated our behavior-driven approach with two practical use cases: service function chaining deployed on OpenStack, supported by both ONOS and Ryu controllers, and dynamic firewall programming. We also measured the overhead and response time of our NBI. We believe that our approach is far more general and paves the way for a more expressive and simplified northbound interface for intent-driven networking.