Implementing hierarchical scheduling on COTS Ethernet switches using a master/slave approach

Hierarchical scheduling is instrumental to efficiently deploy component-based designs and achieve composability. It allows partitioning resources into multiple levels, hiding the complexity within each partition behind its respective interface. In this paper we focus on the network resource, particularly on Ethernet using ordinary COTS switches, and we show how hierarchical scheduling can be efficiently deployed using a master/slave approach that enforces the temporal properties of the partitions. We use the FTT-SE protocol for being open source and a bandwidth efficient master/slave alternative currently available for real-time communication over Ethernet. We present a response-time analysis for the traffic submitted within each partition and we validate it using experimental results obtained from a prototype implementation. In particular, the results highlight the strong partitioning capabilities of our approach, with full temporal isolation across partitions in different branches of the hierarchy.