The AMF may request PDU Session Release towards an alternative V/I-SMF in the same SMF Set when it detects the V/I-SMF has failed and if the V/I-SMF supports the DLSET feature while the (H-)SMF doesn't support the PSETR feature as specified in
clause 6.8.2 of TS 23.527. When the AMF sends an Update SM Context Request, the requirements specified in
clause 5.2.2.3.1 shall apply with the following modifications.
Step 1.
Same as step 1 of
Figure 5.2.2.3.1-1, with the following modifications.
The POST request shall contain:
-
the release IE set to true;
-
the cause IE set to REL_DUE_TO_SMF_NOT_SUPPORT_PSETR.
The NF Service Consumer (e.g. AMF) shall request the SMF to apply CN based MT communication handling as specified in
clauses 4.8.1.1a and
4.8.2.2b of
TS 23.502 when the AMF is notified by the NG-RAN that the NG-RAN has transited the UE using eDRX to RRC_INACTIVE state and the SMF supports the UPCSMT feature (see
clause 6.1.8).
Upon receiving a notification from NG-RAN that the UE is in RRC_CONNECTED mode or when receiving from NG-RAN a MT Communication Handling request indicating the UE is now reachable for downlink data and/or signalling as specified in
clause 4.8.2.2 of TS 23.502, the NF Service Consumer (e.g. AMF) shall request the SMF to resume the User Plane connection of an existing PDU session, i.e. establish the N3 tunnel between the 5G-AN and UPF, as follows.
The requirements specified in
clause 5.2.2.3.1 shall apply with the following modifications.
Step 1.
Same as step 1 of
Figure 5.2.2.3.1-1, with the following modifications.
The POST request shall contain:
-
the release IE set to true;
-
the cause IE set to "REL_DUE_TO_NSI_NOT_AVAILABLE".
The requirements specified in
clause 5.2.2.3.1 shall apply with the following modifications.
Step 1.
Same as step 1 of
Figure 5.2.2.3.1-1, with the following modifications.
The POST request shall contain:
-
the release IE set to true;
-
the cause IE set to "REL_DUE_TO_MBSR_NOT_AUTHORIZED".