E.0 General

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

This clause describes the main IP-Connectivity Access Network specific concepts that are used for the provisioning of IMS services over GPRS and EPS system using GERAN and/or UTRAN radio access and/or E-UTRAN (using EPC only).

When using GPRS-access, the IP-Connectivity Access Network bearers are provided by PDP Context(s).

When using EPS the SGSN is responsible for mapping PDP Context(s) to EPS bearers, i.e. the UE (using GERAN/UTRAN) is using PDP Context(s) whereas EPS bearers are used from the SGSN towards the S‑GW/P‑GW. However, throughout this annex PDP context(s) are used when referring to an IP‑CAN bearer for GPRS networks and when a UE is connected to EPS via GERAN/UTRAN access.

When GGSN/P‑GW is shown, it represents either a GGSN or a P‑GW for a specific UE connection towards a PDN.