Performance Evaluation on Packet Transmission for AFDX Networks Using Optimized Forward End-to-End Delay Analysis

AFDX (Avionics Full Duplex switched Ethernet) standardized as ARINC 664 is chosen as the backbone network for distributed real-time avionics systems as it offers high throughput and does not require global clock synchronization. A deterministic upper bound of the end-to-end transmission delays for packets of each flow should be guaranteed to ensure the network performance. In this paper, we focus on the forward end-to-end delay analysis (FA). This approach iteratively estimates the maximum backlog (amount of the pending packets) in the switch output port along the transmission path so that the worst-case end-to-end transmission delay can be computed and the network performance can be evaluated. Recent research demonstrates this approach is pessimistic (overestimated). This paper presents an optimization which considers the serialization effect of packets transmitted through the same physical link. We provide a comparative analysis on both sample network configurations and real industrial systems. The experiments show that by considering the serialization effect the forward end-to-end delay analysis can remove the pessimism in the analysis of end-to-end transmission delay. The evaluation of network performance can be improved. Then a discussion on the potential optimism (underestimation) is presented.