Controller Area Network (CAN) is becoming a de facto standard for data transmission in automotive applications. Such applications are characterized by their obligation to respect stringent time and dependability constraints. This is why it is vital, at the design step, to validate their behavior. By validation, we mean verifying that the application's contraints will be met by the designed solution, or Operational Architecture (OA), which results from mapping the application level functions onto a material architecture (microcontroller, network...). The verification is based on the performance evaluation of the OA. Our approach involves 1) building models (both analytic and simulation) and solving them (model based evaluation) and 2) performing network monitoring on a prototype of the system (prototype based evaluation).