4.2.3 PCRF-Initiated
29.2133GPPPolicy and charging control signalling flows and Quality of Service (QoS) parameter mappingRelease 17TS
4.2.3.1 AF located in the HPLMN
This clause is applicable if an IP-CAN Session is being released by the PCRF and the AF is located in the HPLMN.
Figure 4.2.3.1.1: PCRF-initiated IP-CAN Session Termination – AF located in HPLMN
In the following procedures, the V-PCRF is included to depict the roaming scenarios. H-PCRF acts as the PCRF for non-roaming Ues.
1. The H-PCRF detects that the termination of an IP-CAN Session is required.
2. For the non-roaming case, and for the case when the UE is roaming in a Home Routed scenario, the H-PCRF sends a RAR including the Session-Release-Cause AVP to request that the PCEF terminates the IP CAN session.
For the case when the UE is roaming in a Visited Access scenario, steps 2a~2b are executed instead of step 2:
2a. If case 2b or case 1 applies and the subsession being terminated is the last subsession over S9, the H-PCRF sends a RAR including the Session-Release-Cause AVP to the V-PCRF to indicate the termination of the S9 session. Otherwise, the H-PCRF sends a RAR to the V-PCRF including the Subsession-Decision-Info AVP with the Session-Release-Cause AVP to indicate the request for terminating the S9 subsession corresponding to the IP-CAN session.
2b. The V-PCRF sends a RAR including the Session-Release-Cause AVP to the PCEF.
3. The PCEF removes all the PCC Rules which are applied to the IP-CAN session.
4. For the non-roaming case, and for the case when the UE is roaming in a Home Routed scenario, the PCEF sends a RAA to acknowledge the RAR.
For the case when the UE is roaming in a Visited Access scenario, steps 4a~4b are executed instead of step 4:
4a. The PCEF sends a RAA to the V-PCRF.
4b. The V-PCRF sends a RAA to the H-PCRF and acknowledges the request for terminating the S9 session or the S9 subsession corresponding to the IP-CAN session.
5. The PCEF applies IP CAN specific procedures to terminate the IP CAN session.
6. – 21. Same as Steps 3-18 in figure 4.2.2.1.1.
4.2.3.2 AF located in the VPLMN
This clause is applicable only for the Visited Access scenario for the case when an IP-CAN Session is being released by the PCRF and the AF is located in the VPLMN
Figure 4.2.3.2.1: PCRF-Initiated IP-CAN Session Termination – AF located in the VPLMN
If the AF resides in the VPLMN, the V‑PCRF proxies AF session signalling over S9 between the V-AF and the H‑PCRF.
1. In order to perform PCRF initiated IP-CAN Session Termination Procedures, step 1 through step 12: asspecified in Figure 4.2.3.1.1: PCRF Initiated IP-CAN Session Termination – AF Located in the HPLMN areexecuted.
For each AF session identified in step 6 (Figure 4.2.3.1.1) as bound to the IP-CAN Session being removed, steps 2-9 are executed:
2. The H-PCRF indicates the session abort to the V-AF in VPLMN by sending an ASR to the V-PCRF.
3. The V-PCRF proxies the ASR to the V-AF.
4. The V-AF responds by sending an ASA to the V-PCRF.
5. The V-PCRF proxies the ASA to the H-PCRF.
6. The V-AF sends an STR to the V-PCRF to indicate that the session has been terminated.
7. The V-PCRF proxies the STR to the H-PCRF.
8. The H-PCRF responds by sending an STA to the V-PCRF.
9. The V-PCRF proxies the STA to the V-AF.
10. Step 17 through step 20: as specified in Figure 4.2.3.1.1: PCRF Initiated IP-CAN Session Termination – AF Located in the HPLMN are executed, as needed.
NOTE: For steps 19 and 20: the details associated with the Sp reference point are not specified in this Release. The SPR’s relation to existing subscriber databases is not specified in this Release.