NF_CONSUMER_REDIRECT_ONE_TXN

307 Temporary Redirect

The request has been asked to be redirected to a specified target.

HANDOVER_FAILURE

403 Forbidden

Creation of UE context or relocation in the target AMF failed during Handover procedure causing a failure of handover.

INTEGRITY_CHECK_FAIL

403 Forbidden

Integrity check of the complete registration message included in the UE context transfer request failed.

EBI_EXHAUSTED

403 Forbidden

Allocation of EPS Bearer ID failed due to exhaustion of EBI as the maximum number of EBIs has already been allocated to the UE.

EBI_REJECTED_LOCAL_POLICY

403 Forbidden

Allocation of EPS Bearer ID failed due to local policy at the AMF as specified in clause 4.11.1.4.1 of 3GPP TS 23.502 [3].

EBI_REJECTED_NO_N26

403 Forbidden

The allocation of EPS Bearer ID was rejected when the AMF is in a serving PLMN that does not support 5GS-EPS interworking procedures with N26 interface.

SUPI_OR_PEI_UNKNOWN

403 Forbidden

The SUPI or PEI included in the message is unknown.

UE_IN_NON_ALLOWED_AREA

403 Forbidden

UE is currently in a non-allowed area hence the N1/N2 message transfer cannot be completed because the request is not associated with a regulatory prioritized service.

UNSPECIFIED

403 Forbidden

The request is rejected due to unspecified reasons.

SM_CONTEXT_RELOCATION_REQUIRED

403 Forbidden

The request is rejected because the SM Context should be relocated to another SMF, e.g. when AMF detects that an I-SMF or V-SMF insertion, change or removal is needed, as specified in clause 4.23 of 3GPP TS 23.502 [3].

UE_WITHOUT_N1_LPP_SUPPORT

403 Forbidden

UE does not support LPP in N1 mode hence the N1 LPP message cannot be sent to the UE.

INVALID_SM_CONTEXT

403 Forbidden

The request is rejected because the SM Context is invalid for the PDU session, i.e. active SM Context for the PDU session (with same PDU Session ID) has been created on another SMF.

(NOTE)

CONTEXT_NOT_FOUND

404 Not Found

The requested UE Context does not exist on the AMF

HIGHER_PRIORITY_REQUEST_ONGOING

409 Conflict

Paging triggered N1/N2 transfer cannot be initiated since already there is a paging due to a higher priority session ongoing.

TEMPORARY_REJECT_REGISTRATION_ONGOING

409 Conflict

N1/N2 message transfer towards UE / AN cannot be initiated or the EBI assignment fails due to an ongoing registration procedure.

TEMPORARY_REJECT_HANDOVER_ONGOING

409 Conflict

N1/N2 message transfer towards UE / AN cannot be initiated due to an ongoing Xn or N2 handover procedure, or the EBI assignment fails due to an ongoing N2 handover procedure or an ongoing Xn handover procedure.

UE_IN_CM_IDLE_STATE

409 Conflict

N2 message transfer towards 5G-AN cannot be initiated due to the UE being in CM-IDLE state for the Access Network Type associated to the PDU session.

MAX_ACTIVE_SESSIONS_EXCEEDED

409 Conflict

If the RAT type is NB-IoT, and the UE already has 2 PDU Sessions with active user plane resources.

REJECTION_DUE_TO_PAGING_RESTRICTION

409 Conflict

If Paging Restrictions information restricts the N1N2MessageTransfer request from causing paging as defined in 3GPP TS 23.501 [2] clause 5.38.5.

UE_NOT_REACHABLE

504 Gateway Timeout

The UE is not reachable for paging.

UE_NOT_RESPONDING

504 Gateway Timeout

The UE is not responding for paging.

NOTE: More than one SM Contexts may be present in the network for the same PDU Session ID, e.g. when the UE established a new PDU session with the same PDU Session ID and the AMF failed to release the old SM Context in the old SMF. In such a scenario, if the old SMF tries to send N1 and/or N2 Message to the RAN/UE, the AMF shall respond with this application error if the AMF identified that service operation is invoked by the SMF holding the old SM Context.