5.0 General

23.2283GPPIP Multimedia Subsystem (IMS)Release 18Stage 2TS

This clause documents the main procedures that are used for the provision of services in the IP multimedia subsystem. These procedures are described using text description as well as information flow diagrams. The procedures described in this document are meant to provide a high level description and are not intended to be exhaustive.

In the following clauses, user roaming procedures apply to cases where P‑CSCF is located in the visited network. Procedures for cases where the user is roaming and the P‑CSCF is located in the home network are similar to procedures for a non-roaming user.