Dynamic QoS Configuration of a DVB-RCS Satellite Terminal for SIPbased Applications
Résumé
Satellite systems were long-dedicated mainly to broadcast services as television whereas Internet access was offered by terrestrial networks as DSL technologies. However, the democratization of DVB-S terminal, the standardization of a return channel via satellite (DVB-RCS) and the significant breakthroughs leading to DVB-S2 standard have allowed them to represent an interesting alternative to terrestrial networks in remote areas. But, to be competitive, DVB-S2/RCS systems have to offer an appropriate support to the variety of current and future multimedia applications (VoIP, videoconferencing) by providing QoS guarantees in spite of its specific characteristics: a long transmission delay and a limited bandwidth. In this context, this paper considers a DiffServ architecture, compliant with the SatLabs recommandations, in which three classes are considered at the IP layer to differentiate the traffic: EF, dedicated to real-time applications with strong time-constraints, AF used for non real-time applications and BE. Each Diffserv classe is mapped on a specific MAC queue to take benefit of the DAMA (Demand Assignment Multiple Access) mechanisms which allow the ST to dynamically request capacity to the NCC (Network Control Center). The goal of this work is to configure dynamically the DiffServ classes of service of the Linux-based ST for interactive applications, as VoIP, by using the session descriptors contained in SIP messages. For that, a complete QoS architecture based on the communication between an enhanced SIP proxy and a QoS Server and/or an ARC (Access Resource Controller) has been designed, developed and evaluated on a satellite network emulation testbed (PLATINE), implemented in the SatIP6 and SatSIX IST projects.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...