Performance Evaluation of a VANET Simulation System Using NS-3 and SUMO In this paper, we investigate the performance of HWMP, OLSR and DD protocols in a VANET crossroad scenario. The mobility patterns of vehicles are generated by means of SUMO (Simulation of Urban Mobility) and as communication protocol simulator is used NS3 (Network Simulator 3). For the simulations, we used IEEE 802.11p standard, Two Ray Ground Propagation Loss Model and sent multiple CBR flows over UDP between 20 source-destination pairs. We use Packet Delivery Ratio (PDR), throughput and delay as evaluation metrics. We compared the performance of three protocols and the simulation results shows that the DD protocol has better PDR and throughput compared with HWMP and OLSR protocol. However, the DD protocol has a long delay because is a delay tolerant protocol.