Sequential network simulation is a high time-consuming application, and with the emergence of global multihop networks and gigabit-per-second links is becoming a challenging problem. A new approach to this open problem is presented, based on HW/SW co-design. A complete modular and scalable reconfigurable system architecture is explained. Most important features of this simulation framework are: (1) efficient and flexible network simulation, and (2) transparent use of the reconfigurable system by telecommunication networks engineers because of the use of a high level network modeling language.