Ultra Cloud Core 5G Access and Mobility Management Function, Release 2021.04 - Configuration and Administration Guide - Idle Entry Procedure [Cisco Ultra Cloud Core - Access and Mobility Management Function]

Idle Entry Procedure

Feature Summary and Revision History

Table 1. Summary Data
Applicable Product(s) or Functional Area	AMF
Applicable Platform(s)	SMI
Feature Default Setting	Enabled - Always-on
Related Documentation	Not Applicable

Table 2. Revision History
Revision Details	Release
First introduced.	2021.04.0

This section describes how this feature works.

This section describes the key call flow for this feature.

This section describes the gNB-Initiated UE Context Release Procedure call flow.

Table 3. gNB-Initiated UE Context Release Procedure Call Flow Description
Step	Description
1	AMF receives UE Context Release Request from gNB.
2	AMF sends UE Context Release Command to gNB.
3	AMF receives UE Context Release Complete from gNB.
4	SmContextUpdate procedure is initiated for all existing PDU sessions of the subscriber.
5	Once the SmContextUpdate is complete, UE is moved to Idle state.
6	T3512 Timer is started.
7	On expiry of T3512 timer, the UE Detach Timer is started.
8	On expiry of UE Detach Timer, the deregistration procedure is triggered.

This section describes the UE/NW Initiated Deregistration followed by UE Release Procedure call flow.

Table 4. UE Context Release Procedure after Deregistration Call Flow Description
Step	Description
1	UE/NW Initiated Deregistration procedure is completed. Deregistration Req/Accept is completed and UE is moved to Deregistered state.
2	AMF Sends UE Context Release Command to gNB.
3	AMF receives UE Context Release Complete from gNB.
4	As UE deregistration is already done and UE is moved to Deregistered state, UE Context/Subscriber cleanup is triggered, and subscriber and session is deleted from CDL.