In the last years, broadband satellite networks have emerged as a flexible technology offering high-speed Internet access to large communities of users at relatively low-cost. At the same time, the large widespread of VoIP and Multimedia over IP (MoIP) applications, has pointed out the need of investigating their performance over heterogeneous networks and, more specifically, on wireless and satellite systems not offering Quality of Service (QoS) guarantee. The paper presents the results of an experimental study aimed at analyzing the behaviour of MoIP applications over a two-way satellite system. Starting from the most relevant performance metrics of a satellite network, the paper is focused on the evaluation of the Perceived Quality of Service (PQoS) when VoIP and MoIP applications are deployed over a satellite network. Control and data plane issues that may deteriorate the performance of such applications are highlighted.