6.17 Service-level Interworking: SMS user requesting the IP-SM-GW to tear down the Chat session between a CPM user and an SMS user

23.2043GPPRelease 17Stage 2Support of Short Message Service (SMS) over generic 3GPP Internet Protocol (IP) accessTS

6.17.1 IP-SM-GW in the originating network

Figure 6.17.1: Chat session teardown request to CPM UE (IP-SM-GW in originating network)

1) A message is received from the SMS user via the SMS-GMSC by the IP-SM-GW, in accordance to steps 2 to 4 and steps 10 to 13 of clause 6.14, with the operator defined Short Message indicating the SMS user wants to leave the chat session.

2) The IP-SM-GW performs service-level interworking by recognizing that the Short Message corresponds to the operator defined teardown text indicating the SMS user wants to leave the chat session, so the IP-SM-GW sends a chat session teardown request.

3) The session teardown request is forwarded by S-CSCF to the CPM UE.

4) The CPM UE acknowledges the session teardown request.

5) The acknowledgement is forwarded by the S-CSCF to the IP-SM-GW.

6.17.2 IP-SM-GW in the terminating network

The SMS user in this flow is a CPM user who has set his preferences in his home network to receive his incoming chat sessions as Short Messages.

Figure 6.17.2: Chat session teardown request to CPM UE (IP-SM-GW in terminating network)

1) A message is received from the SMS user via the SMS-GMSC by the IP-SM-GW, in accordance to steps 2 to 4 and steps 10 to 13 of clause 6.14, with the operator provided teardown text indicating the SMS user wants to leave the chat session.

2) The IP-SM-GW performs service-level interworking by recognizing that the Short Message corresponds to the operator provided teardown text indicating the SMS user wants to leave the chat session, so the IP-SM-GW sends a chat session teardown request.

3) The session teardown request is forwarded by the S-CSCF towards the CPM user’s originating network.

4) The CPM user’s originating network acknowledges the session teardown request and tears down the associated resources.

5) The acknowledgement is forwarded by the S-CSCF to the IP-SM-GW.