We introduce a high-fidelity simulation model to evaluate the power consumption of computer networks derived from measured data on routers. To this end, we design and use a power consumption profiling system to parameterize the electrical power consumption of network elements in terms of data traffic. A model validation done by comparing simulation outputs for a test case with actual measurements from an equivalent network testbed confirms the accuracy of the model. Finally, we apply the model to investigate power saving routing on a representative MPLS network. © 2010 IEEE.