Nowadays massive access to the new cellular technologies is no longer an idea but a tangible reality. Among them, the GSM/GPRS/EDGE architecture represents without any question the most Worldwide spread of them. Costs decreases in both infrastructure and personal equipment has largely increased the number of users. This abrupt growth poses a difficult challenge for telecom operators when it comes to dimensioning and evaluating the performance of their networks. Previous works have studied the problem of modelling GSM/GPRS/EDGE networks, paying little attention to many technical implementation features of determinant impact. This work addresses the performance evaluation problem of these networks, focusing on the influence of different operational details. Different data and voice models are studied, including a traffic prioritization model of great relevance facing the increasing popularity of new multimedia services offered through these networks. The proposed models are finally applied to the performance evaluation of the local operator s network.