RAN-initiated PDU Session Release Call Flow

The RAN-initiated PDU session release procedure allows the RAN to initiate the release of a PDU session.

The following figure depicts the RAN-initiated PDU session release call flow.

RAN-initiated PDU Session Release Call Flow
AMF-initiated PDU Session Creation Call Flow Description
Step Description
1

The AMF sends SmContextModifyRequest with N2 type: N2_PDU_SESSION_RESOURCE_NOTIFY_RELEASED_TRANSFER.

2, 3

The SMF sends N4SessionModificationRequest to the UPF with changing packet rule to Buffer from Forward. The UPF sends the response for the same, that is, the SMF moving to IDLE state.

4

The SMF sends SmContextUpdateResponse message with UpState as Deactivated.