PCRF-initiated Detach Procedure
The following call flow illustrates the procedure in which the E-UTRAN network (PCRF) initiated detach.

Step | Description |
---|---|
1 |
PCRF sends Gx Credit Control Answer or RAR with session release cause to SMF. |
2 |
SMF sends N4 PFCP Session Modification Request to UPF with FARs having apply action set to Drop |
3 |
UPF sends N4 PFCP Session Modification Response to SMF. |
4 |
SMF sends Delete Bearer Request to S-GW. |
5 |
S-GW sends Delete Bearer Request to MME. |
6 |
MME sends Delete Bearer Response to S-GW. |
7 |
S-GW sends Delete Bearer Response to SMF. |
8 |
SMF sends N4 PFCP Session Deletion Request to UPF to release N4 session. |
9 |
UPF sends N4 PFCP Session Deletion Response to SMF. |
10 |
SMF sends Radius Accounting Request Stop to AAA server to release radius session. |
11 |
AAA server sends RADIUS Accounting Response to SMF. |
12 |
SMF sends Gx Credit Control Request Terminate to OCS to release Gy session. |
13 |
OCS sends Gx Credit Control Answer Terminate to SMF. |
14 |
SMF sends Gx Credit Control Request Terminate to PCRF to release Gx session. |
15 |
PCRF sends Gx Credit Control Answer Terminate to SMF. |