Investigation on a distributed SDN control plane architecture for heterogeneous time sensitive networks

Data-driven services (optimization or condition monitoring) are often deployed using cloud architectures. The shop floor itself becomes more and more flexible and reconfigurable using modular machine design and Plug and Play services. These industrial use cases induce additional requirements to communication systems: scalable real-time communication from sensor to cloud as well as seamless and automatic network configuration on the shop floor. A promising data plane technology for the Industrial Internet of Things (IIoT) is IEEE 802.1 Ethernet TSN that allows convergent and time sensitive communication. The configuration of the IIoT is complex because the IIoT is often large, growing and changing over time and often consists of heterogeneous network domains because of the brownfield and manifold requirements from the applications. Software-defined Networking (SDN) has the potential to reduce the engineering effort and to increase the operation efficiency (monitoring, diagnosis, reconfiguration) of heterogeneous IIoT. SDN Control Planes can be implemented as physical-central, logic-central, distributed or hybrid architecture. The different architectures have specific advantages and disadvantages regarding QoS, throughput and engineering efforts. A key role takes the East-West interface that handles the communication between distributed SDN Controllers. SDN Data Plane agents can help to manage legacy Data Planes with SDN. A TSN Nano Profile with inverse and cooperative operating Time Aware Shaper is a migration solution to upgrade legacy communication controllers with TSN functions. The disadvantages are less throughput and increased latency for acyclic traffic.