We study the connectivity properties of an ad hoc network consisting of n nodes each moving according to the Random Waypoint mobility model. In particular, we focus on estimating two quantities, the probability that the network is connected, and the mean durations of the connectivity periods. The accuracy of the approximations is compared against numerical simulations. For the probability of connectivity, an approximation is given that is remarkably accurate. By numerical examples we also show that in sparse network the mobility has a positive effect on connectivity, whereas in dense network the situation becomes the opposite. For the mean length of the connectivity periods results are also accurate in the important region where the probability of connectivity rises rapidly.