7.3.1 Originating sessions that use PS media

23.2923GPPIP Multimedia Subsystem (IMS) centralized servicesRelease 17Stage 2TS

When the ICS UE has access to a PS network that supports the full duplex speech component of an IMS service, the originating IMS procedures (as described in clause 5.6 of TS 23.228 [2]) shall be used to set up the session. The S‑CSCF shall insert the SCC AS in the IMS session path using originating initial filter criteria. The SCC AS shall be the first AS inserted into the session path.