The present document defines an open specification for enabling QoS for IP-based multimedia satellite systems, based on the IntServ model, including the use of RSVP for resource allocation and control IETF RFC 2210 [4]. The focus is on the mapping of IP-layer QoS functions, primarily the Guaranteed (GS IETF RFC 2212 [6]) and Controlled Load (CL IETF RFC 2211 [5]) services, to BSM-specific QoS functions across the SI-SAP. This results in specifications for the SI-SAP including its interactions with higher and lower layers.

The present document is based on the findings of the Technical Report on Performance, Availability and Quality of Service ETSI TR 102 157 [i.2] and the Technical Specification on QoS Architecture ETSI TS 102 462 [1]. It is also based on current ETSI BSM architecture document ETSI TS 102 292 [i.3] and is aligned with the relevant IETF standards.

The key to providing real-time multimedia services such as those offered by the IntServ model is the interaction of a resource reservation protocol like RSVP with lower layer (i.e. link layer) resource reservation. For IntServ provision in a BSM network the concept of QIDs (Queue Identifiers) at the SI-SAP is the concept used to provide this interaction with alternative link layers, ETSI TS 102 357 [2]. QIDs represent abstract queues, each with a defined class of service, for transfer of IP packets to the SD layers. The satellite dependent lower layers are responsible for assigning satellite capacity and/or particular forwarding behaviour to these abstract queues according to defined properties.

The present document deals with the QoS issues arising in the management of these QIDs, when IntServ is adopted at IP layer.

A BSM IntServ functional architecture is described and the functions, protocols and primitives needed to ensure QoS provision are specified.

IntServ for unicast services is the primary focus of the present document, although the approach described may also be applicable to multicast.

The use of other IP resource reservation protocols such as NSIS is at present excluded from the present document.

NOTE: RSVP can be used for a number of other functions, apart from IntServ Resource reservation, which are not in the scope of the present document:

• DiffServ resource reservation.
• Policy distribution.
• Traffic engineering.