Section: 6.4.3.4 UE-requested PDU session release procedure not accepted by the network
Content: Upon receipt of a PDU SESSION RELEASE REQUEST message, if the SMF does not accept the request to release the PDU session, the SMF shall create a PDU SESSION RELEASE REJECT message. The SMF shall set the 5GSM cause IE of the PDU SESSION RELEASE REJECT message to indicate the reason for rejecting the PDU session release. The 5GSM cause IE typically indicates one of the following SM cause values: #35 PTI already in use; or #43 Invalid PDU session identity; or #95 – 111: protocol errors. The SMF shall send the PDU SESSION RELEASE REJECT message. Upon receipt of a PDU SESSION RELEASE REJECT message and a PDU session ID, using the NAS transport procedure as specified in subclause 5.4.5, the UE shall stop timer T3582, release the allocated PTI value and locally release the PDU session. If there is one or more multicast MBS sessions associated with the PDU session, the UE shall locally leave the associated multicast MBS sessions.