NUTS: Network Updates in Real Time Systems

Factories need to adapt their communication networks to versatile customer-driven markets. Software defined networking enables a programmatic approach that provides modularity, flexibility and paves the road for behavior certification. Previous works proposed rigorous programming languages and abstractions offering safety properties and verification in best-effort environments. In this work, we propose an approach to provide live update of network elements behavior while respecting real-time constraints. During the network updates, the traffic can be deviated to devices not involved in the desired upgrade ensuring that communication invariant and software requirements are always taken into account. We leverage Temporal NetKAT to write network wide programs and P4 annotations to give indications on the impact of the implementation on deterministic real-time communications passing through network appliances.