This paper investigates the impact of traffic arrival distributions on a typical 802.11 ad hoc network using simulation and modeling. In the investigation, four diverse traffic models (Exponential, Pareto, Poisson, and Constant bit rate) are considered for TCP and UDP. Results show that the network performance for Poisson arrivals is almost independent of traffic load for TCP and UDP but not for Constant bit rate (CBR). However, for both the Pareto and Exponential packet arrivals the network performance is almost independent of load for TCP, but is sensitive to UDP. The network achieves best and worst throughput performance for CBR and Poisson, respectively. The analysis and research findings reported in this paper provide some insight into the impact of the choice of traffic arrival distributions and transport protocols on wireless local area network (WLAN) performance.