6.5 Transport-level interworking: Delivery Report procedure
23.2043GPPRelease 17Stage 2Support of Short Message Service (SMS) over generic 3GPP Internet Protocol (IP) accessTS
Figure 6.5: Delivery report procedure
1) The UE has received the Short Message as described in clause 6.4 or clause 6.4a.
2) The UE sends a Delivery report (SMS‑DELIVER‑REPORT) to the S-CSCF, including either a positive or a negative acknowledgement to the Short Message received in step 1.
3) The S-CSCF forwards the Delivery report to the IP-SM-GW (AS). It shall be ensured that the Delivery report reaches the same IP-SM-GW that forwarded the Short Message in step 1.
4) IP-SM-GW (AS) acknowledges, at the SIP level, the Delivery report to S-CSCF.
NOTE: This is the acknowledgement to the Forward Short Message in the SM termination procedure.
5) S-CSCF forwards the SIP acknowledgement to the Delivery report to the UE.
6) The IP-SM-GW (AS) sends a Delivery report to the SMS-GMSC or to originating IMS network for MSISDN-less SMS operation.
7) The IP-SM-GW may send a Report SM Delivery Status to the HSS. This may trigger the Alert service centre procedure or an update of the message waiting data in the HSS as described in TS 23.040 [2], if necessary.
8) The SMS-GMSC may send a Report SM Delivery Status to the HSS. The HSS shall ignore the information provided in this report.