Response time analysis in AFDX networks with sub-virtual links and prioritized switches

The ARINC-664, Part 7 (AFDX) standard defines a communications network based on Ethernet and the UDP/ IP protocols. Contrary to general-purpose Ethernet, the timing behavior in AFDX is deterministic due to the use of special network switches and end-systems with static routing tables and traffic policing at the sending end through mechanisms called virtual links. Even though the latencies in this network are bounded, there are scheduling and contention effects that need to be analyzed. In this paper we develop a response-time analysis of the network including the scheduling of the virtual links and the contention in the end-systems and in the switches. This analysis allows us to obtain worst-case latencies and output jitter for the network messages. These results can be integrated with the response time analysis in other resources to obtain end-to-end response times in heterogeneous distributed systems.