scope:

The scope for the present document is to specify normative rules for how to use the Gq', Rq and Ia protocols (TS 183 017 [4], ES 283 026 [3] and ES 283 018 [7]) as of TISPAN release 1. These rules apply to the interface between:

• P-CSCF and SPDF using Gq';

• IBCF and SPDF using Gq';

• SPDF and (C- and I-) BGF using Ia;

• SPDF and A-RACF using Rq.

In addition, to illustrate the usage of these rules, the present document contains informative signalling flows between the above-listed entities.

Non IMS AF entities are out of scope of the present document. Thus, the rules for using the Gq', Rq and Ia protocols and the signalling flows provided do NOT cover possible signalling scenarios for non-IMS applications. They describe however basic principles for how parameters travel via these protocols for IMS, which should be considered when using these protocols for non-IMS AF entities. In case of any discrepancy between the end-to-end IMS signalling flows in the present document and the ETSI TISPAN IMS specifications (TS 182 006 [5] and ES 283 003 [6]), the ETSI TISPAN IMS specification shall take precedence.