In this paper we compare two simulators: ns-3 and Vienna, in the context of LTE networks, on four basic scenarios for which well-known analytical results exist. These scenarios differentiate themselves by the nature of the traffic (data or voice) and by the number of sources (infinite or finite). Our goal is twofold. First, by confronting the results of the two simulators with exact results, we can assess the accuracy of both simulators and compare their efficiency. Second, and maybe more important, we want to compare the ease of handling and use of both simulators, and list the difficulties encountered in the context of the four basic scenarios, that will necessarily arise in more realistic simulated scenarios, and explain how we worked around the problems. We hope this comparison will help researchers who work on LTE net- works to choose the simulator that best suits their needs.