Real-Time QoS DiffServ Gateway Implementation for Satellite IP Networks

IP satellite networks are gaining a considerable interest and this is mainly due to their ability to deliver high bandwidth services to nation-wide areas. Some difficulties exist, however, to implement IP based transport mechanisms on geo-stationary satellite networks. TCP based protocols performance are heavily affected by the large delay-bandwidth product on GEO satellites and by the coexistence of UDP and TCP on the same limited resource. In the literature several methods have been proposed to provide quality of service control on IP networks. The most scalable approach is the Differentiated Services (DS). This paper proposes a real-time implementation of a satellite system, mapping the DS entities on software elements on a Linux platform. A detailed analysis has been computed to verify the performance of the RED/DS method with real traffic flows and some optimization are suggested.