SDN Northbound REST API with Efficient Caches

In this paper, we present a REST Chart based approach to design and implement RESTful northbound API in SDN. In our approach, the RESTful API is modeled with Petri Net, and REST constraints, such as hypermedia driven, are enforced naturally. The RESTful structure of the designed northbound API can be checked almost automatically based on the described REST Chart model. The proposed approach has been applied to design and implement the northbound API of SDN in data center networks with OpenStack Neutron. To improve the protocol efficiency, we developed a structured caching mechanism for data network applications with SDN, that reduces the response time overheads by more than 65%, while it fully maintains the desired flexibility and scalability of the RESTful northbound API.