A Light-weight Approach to Obtaining NF State Information in SDN+NFV Networks

The combination of Network Function Virtualization (NFV) and Software Defined Networking (SDN) possesses a great potential in accommodating dynamic network control via cloning/migration of virtualized NFs and steering of traffic flows. A great challenge is the lack of the proprietary internal NF state information to the control system (including SDN controller and NFV orchestrator), which may lead to incorrect packet/flow processing at the newly created NF instances. In this work, we design a light-weight approach which can function either independently or as a plug-in to the network control system to reveal the internal NF states. Unlike the previous work, we propose to learn the internal NF states through normal network functions instead of designing extra APIs for certain NFs. Moreover, we propose a feasible way to detect state violations and even correct them automatically. Our approach is tested by experiments, and the results confirm its efficiency and practicability.