Nowadays, Industrial Control Systems (ICSs) are becoming larger and implement more complex functions. Therefore, technologies that are currently used to implement these functions, like hardware platforms and communication protocols might soon become unusable due to the lack of resources. The industry is trying to adopt new technologies that will allow these functionalities to be developed without an increase in the size of the equipment, or of the development costs. To enumerate some of these technologies: virtualization, multi-core technologies are the ones that show the biggest potential. Because these technologies are not mature, research has to be done in order to fully maximize their potential. Another technology that is highly used by the industry is the Ethernet communication protocol. It presents some advantages, but due to the non-real-time nature of the applications that it was designed for, it has to be extended in order to be used in real-time applications. The objective of this thesis work is to model an Ethernet network comprised of software partitions so that it can provide timing guarantees for the traffic that traverses the network. A Response Time Analysis for real-time flows over such networks is proposed. The model and the RTA are evaluated by experiments.