Summary - Q.3921 (01/2026) - Test framework for software-defined networking multi-controller inter-networking using a communication segment

Software-defined networking (SDN) is used by most evolving networks, including the Internet of things, International Mobile Telecommunications-2020 (IMT-2020) and next-generation networks, because of its numerous advantages, which include reducing end-to-end data latency and improving availability, reliability and flexibility of the system. To meet their scalability requirements, most of these systems use SDN networks with multi-controller configurations. There are several challenges in this field, in particular the multi-vendor issue (software and hardware), interfaces limitations, scalability on the control plane and other challenges related to sustainable multi-controller communication.
Recommendation ITU-T Q.3921 describes methods for testing SDN multi-controllers based on model networks.