UE Initiated Detach Procedure
The following figure shows the call flow for an UE-initiated release with Diameter interfaces.

The following table describes the detailed procedure of an E-UTRAN UE-initiated detach.
Step | Description |
---|---|
1 |
MME sends Delete Session Request to S-GW. |
2 |
S-GW sends Delete Session Request to SMF. |
3 |
SMF sends N4 PFCP Session Deletion Request to UPF to release N4 session. |
4 |
UPF sends N4 PFCP Session Deletion Response to SMF. |
5 |
SMF sends Delete Session Response to S-GW. |
6 |
S-GW sends Delete Session Response to MME. |
7 |
SMF sends Radius Accounting Request Stop AAA server to release the accounting session. |
8 |
AAA server sends RADIUS Accounting Response to SMF. |
9 |
SMF sends Gy Credit Control Request Terminate to OCS to release the Gy session. |
10 |
OCS sends Gy Credit Control Answer Terminate to SMF. |
11 |
SMF sends Gx Credit Control Request Terminate to PCRF. |
12 |
PCRF sends Gx Credit Control Answer Terminate to SMF to release the Gx session. |