Extending Openflow with Flexible Time-Triggered Real-Time Communication Services

Emerging concepts such as Smart Production, Industrial Internet of Things and Industry 4.0 bring a radically new set of requirements to the way industrial systems are engineered. In what concerns the communication infrastructure, support to dynamic environments, interoperability and heterogeneity, combined with a significant increase in the number of devices, are just a few of the challenges that must be faced. Software-defined networking is a disruptive networking paradigm that emerged on campus networks but was soon considered for use at industrial level. This paper presents a set of extensions to the Software Defined Networking (SDN) OpenFlow protocol that complement its functionality, namely supporting real-time reservations, which is one of its more notorious limitations when considering industrial scenarios. We explain how the extensions are implemented in the OpenFlow side and enforced using a Flexible Time-Triggered Ethernet network. The extensions are validated experimentally, showing that the platform supports dynamically reconfigurable heterogeneous traffic classes.