Software-defined Flow Reservation: Configuring IEEE 802.1Q Time-Sensitive Networks by the Use of Software-Defined Networking
Communication systems are core elements of future cyber-physical systems (Industrial Internet, Industry 4.0, Internet of Things) which form the basis for applications such as smart production, smart grid, smart city, and the like. These applications will comprise data streams with very different communication requirements regarding data rate, latency, jitter, and reliability that may also vary over time. This calls for communication solutions that on one hand can adapt flexibly and on-demand to these needs and on the other hand can seamlessly support data streams with different quality-of-service requirements. Within this paper we present Software-defined Flow Reservation (SDFR), an approach that combines Software-defined Networking (SDN) technologies with Time-Sensitive Networking. Special focus is on the configuration of the time-sensitive network. SDFR implements the IEEE 802.1Qcc standard in the logically centralized SDN controller and, thus, allows for a flexible software-driven configuration of the underlying network. This flexibility enables operators to support multiple configuration interfaces simultaneously and to easily modify traffic classes, scheduling approaches, and network behavior. SDFR allows to re-use existing solutions for well-understood SDN use cases while simultaneously supporting novel TSN-specific solutions.