Timing verification of real­time automotive Ethernet networks: what can we expect from simulation?

Switched Ethernet is a technology that is profoundly reshaping automotive communication architectures as it did in other application domains such as avionics with the use of AFDX backbones. Early stage timing verification of critical embedded networks typically relies on simulation and worst-case schedulability analysis. When the modeling power of schedulability analysis is not sufficient, there are typically two options: either make pessimistic assumptions or ignore what cannot be modeled. Both options are unsatisfactory because they are either inefficient in terms of resource usage or potentially unsafe. To overcome those issues, we believe it is a good practice to use simulation models, which can be more realistic, along with schedulability analysis. The two basic questions that we aim to study here is what can we expect from simulation, and how to use it properly? This empirical study explores these questions on realistic case-studies and provides methodological guidelines for the use of simulation in the design of switched Ethernet networks. A broader objective of the study is to compare the outcomes of schedulability analyses and simulation, and conclude about the scope of usability of simulation in the design of critical Ethernet networks.