RADIUS-initiated Detach Procedure

The following figure shows the call flow for E-UTRAN RADIUS disconnect messages.

Call Flow Description for RADIUS-initiated Detach
Step	Description
1	AAA Radius Disconnect Message to SMF.
2	SMF sends back Radius Disconnect acknowledgment.
3	SMF sends PCRF Session Modification Request (Update FAR with DROP) to UPF.
4	UPF responds to SMF with PCRF Session Modification Response.
5	SMF sends Delete Bearer Request to S-GW
6	S-GW forwards Delete Bearer Request to MME.
7	MME responds to S-GW with Delete Bearer Response.
8	S-GW forwards Delete Bearer Response to SMF.
9	SMF sends PCRF Session Deletion Request to UPF.
10	UPF responds to SMF with PCRF Session Deletion Response.
11	SMF sends CCR-T to OCS.
12	SMF sends Accounting Request(Stop) to AAA.
13	OCS responds to SMF with CCA-T.
14	SMF responds to AAA with Accounting Response(Stop).
14	SMF sends CCR-T to PCRF.
15	PCRF responds to SMF with CCA-T.