Generally, the real-time applications exchange information on dedicated network and the other traffic is supported by another communication system. The differentiation of these two networks enables to easily guarantee the level of Quality of Service required by the application. The objective of this paper is to study Ethernet network architectures which transport all kinds of information. The mechanism of Classification of Service are modelled by using Network Calculus to adjust the service offered by the network with the information timed requirements. The study analyzes two kinds of scheduling policies and could be used in the framework of entertainment applications in vehicles.