Improving end-to-end delay upper bounds on an AFDX network by integrating offsets in worst-case analysis

Abstract

AFDX (Avionics Full Duplex Switched Ethernet) standardized as ARINC 664 is a major upgrade for avionics systems. The mandatory certification implies a worst-case delay analysis of all the flows transmitted on the AFDX network. Up to now, this analysis is done thanks to a tool based on the Network Calculus approach. This existing approach considers that all the flows transmitted on the network are asynchronous and it does not take into account the scheduling of output flows done by each end system. The main contribution of this paper is to extend the existing Network Calculus approach by introducing the offsets associated to the different periodic flows into the computation. The resulting approach is evaluated on an industrial AFDX configuration with an existing offset assignment algorithm. The obtained upper bounds are significantly reduced.