ETSI TS 102 464

The aim of the present document is to define an open specification for enabling QoS for IP-based multimedia satellite systems, based on the DiffServ model. If IP packets entering the BSM network require a particular QoS treatment, they have to be mapped onto QIDs. The choice of the QID to be used inside the BSM network is thus particularly important. So the present document specifies the allocation of the QIDs and their mapping to IP QoS classes, when DiffServ is used to provide QoS at IP layer. The present document assumes the QoS functional architecture described in ETSI TS 102 462 [2].

The present document describes in detail how QIDs are defined, how they are allocated and handled by the BSM network, and the requirements needed by sending and receiving Satellite Terminals (STs) in a BSM network to provide QID management functionalities. The present document also defines the primitives that should be used across the SI-SAP when allocating QIDs, when mapping DiffServ Code Points (DSCPs) and IP services to QIDs, when mapping QIDs to SD queues.

Details on the QID mapping are presented with some examples. Some cases are presented to show the potential evolution from a simple QoS solution with quasi-static QID allocation to more sophisticated services with dynamic resource reservation.

The combination of DiffServ with multicast transmissions is out of scope of the present document, as well as the use of Explicit Congestion Notification (ECN), which was linked to DiffServ only for historical reasons, as the ECN bits are the two least significant bits of the IPv4 ToS octet. This is better explained in clause 4.