The work presented in this section extends the following congress paper, where we present VanetMobiSim/Ns-2 as VANET simulator. However, nowadays we simulate VANETs coupling SUMO and ns-2. E. Alba, S. Luna & J. Toutouh. Accuracy and Efficiency in Simulating VANETs. Modelling, Computation and Optimization in Information Systems and Management Sciences, Second International Conference, MCO 2008, Metz, France - Luxembourg, September 8-10, 2008.Introduction The emergence of vehicular networks has encouraged the design of a set of new applications and protocols specifically for these kind of networks. The evaluation of those in outdoor experiments, by using large-scale networks to obtain significant results, is extremely dicult due to several issues concerning available resources, accurate performance analysis, and reproducible results. Indeed, it is neither easy nor cheap to have a high number of real vehicles and a real scenario for only practical purposes. It is also difficult to analyze applications and protocols performance in a inherently distributed and complex environment like VANETs. Simulation has become an indispensable tool because it makes possible to build a dedicated VANET for its evaluation. Simulators also gather statistical data about the network usage during the simulation that allows to measure the protocols per- formance. Moreover, it is possible to visualize the VANET in order to easily specify the scenarios for the protocol evaluation. However, due to the complexity of the real world, a lot of the events related to the signal propagation that plays an important role in the performance of the outdoor experiments are missed in the simulations: passing by obstacles, reflection problems, signal interferences, etc. Thus, simulation also presents an important drawback: the fidelity of the generated results. VANET Simulation Alternatives