On hierarchical server-based communication with switched Ethernet

Ethernet is becoming a common network technology for industrial and factory automation systems and, in recent years, a big effort has been made in enabling real-time communications using Ethernet technology. Many of these systems are complex, extend over relatively large places and/or integrate a significant number of nodes, thus requiring the use of multiple switches (hop). In this paper we look into the usage of Flexible Time-Triggered (FTT) enabled Ethernet switches in this class of systems, more specifically using the recently proposed server-based scheduling mechanism supported by this protocol. The paper proposes and validates a resource reservation protocol, presents a method for computing the end-to-end deadlines and discusses possible strategies for the deadline partitioning. 1