3GPP 24.501 v20.0.0 — the document's own text

5.4.5.2.5 Abnormal cases on the network side

Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).

The following abnormal cases in AMF are identified:

If the Payload container type IE is set to "N1 SM information" and:

if the Old PDU session ID IE is not included in the UL NAS TRANSPORT message, the AMF does not have a PDU session routing context for the PDU session ID and the UE, the Request type IE is set to "initial request" or "MA PDU request", and the SMF selection fails, then the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);
if the Old PDU session ID IE is included in the UL NAS TRANSPORT message, the AMF has a PDU session routing context for the old PDU session ID and the UE and does not have a PDU session routing context for the PDU session ID and the UE, the Request type IE is set to "initial request", the AMF received a reallocation requested indication from the SMF indicating that the SMF is to be reallocated, and the SMF selection fails, then the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);
if the AMF does not have a PDU session routing context for the PDU session ID and the UE, the Request type IE is set to "existing PDU session" or "MA PDU request", and the user's subscription context obtained from the UDM does not contain an SMF ID for the PDU session ID matching the PDU session ID received from the UE or for the DNN matching the DNN received from the UE such that the SMF ID includes a PLMN identity corresponding to the UE's HPLMN or the current PLMN or the PLMN ID part of the current SNPN, then the AMF may send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f).
if the Old PDU session ID IE is included in the UL NAS TRANSPORT message, and the AMF has a PDU session routing context for the old PDU session ID and the UE and does not have a PDU session routing context for the PDU session ID and the UE, the Request type IE is set to "initial request" and the AMF has not received a reallocation requested indication, the AMF should select an SMF with following handlings:

if the S-NSSAI IE is not included and the allowed NSSAI contains:

A) one S-NSSAI, the AMF shall use the S-NSSAI in the allowed NSSAI as the S-NSSAI;

B) two or more S-NSSAIs and the user's subscription context obtained from UDM contains only one default S-NSSAI that is included in the allowed NSSAI, the AMF shall use the S-NSSAI in the allowed NSSAI as the S-NSSAI; or

C) two or more S-NSSAIs and the user's subscription context obtained from UDM contains two or more default S-NSSAI(s) included in the allowed NSSAI, the AMF shall use an S-NSSAI in the allowed NSSAI selected based on operator policy as the S-NSSAI;

if the DNN IE is not included, and the user's subscription context obtained from UDM:

A) contains the default DNN for the S-NSSAI, the AMF shall use the default DNN as the DNN; and

B) does not contain the default DNN for the S-NSSAI, the AMF shall use a locally configured DNN as the DNN;

iii) if the DNN selected by the network is a LADN DNN, the AMF shall determine the UE presence in LADN service area (see clause 6.2.6);

if the SMF selection is successful, the AMF should store a PDU session routing context for the PDU session ID and the UE, set the SMF ID in the stored PDU session routing context to the selected SMF ID, and forward the 5GSM message, the PDU session ID, the old PDU session ID, the S-NSSAI, the mapped S-NSSAI (if available), the DNN determined by the AMF, DNN selected by the network (if different from DNN determined by the AMF), the request type and UE presence in LADN service area (if DNN selected by the network corresponds to an LADN DNN) towards the SMF ID of the PDU session routing context; and
if the SMF selection fails, then the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);

if the AMF has a PDU session routing context for the PDU session ID and the UE, the PDU session routing context indicates that the PDU session is an emergency PDU session, the Request type IE is set to "initial emergency request", the AMF should forward the 5GSM message, the PDU session ID, the S-NSSAI (if configured in the AMF emergency configuration data), the DNN (if configured in the AMF emergency configuration data) and the request type towards the SMF ID of the PDU session routing context;
if the Request type IE is set to "initial emergency request" and the S-NSSAI or the DNN is received, the AMF ignores the received S-NSSAI or the DNN and uses the emergency DNN from the AMF emergency configuration data, if any;
if the AMF does not have a PDU session routing context for the PDU session ID and the UE, and the Request type IE of the UL NAS TRANSPORT message is either not provided or is provided but set to other value than "initial request", "existing PDU session", "initial emergency request", "existing emergency PDU session" and "MA PDU request", then the AMF may send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);
if the AMF unsuccessfully attempted to forward the 5GSM message, the PDU session ID, the S-NSSAI, the mapped S-NSSAI (if available), the DNN and the request type (if received) towards a SMF ID, then the AMF may send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f).
if the Old PDU session ID IE is included in the UL NAS TRANSPORT message, the AMF does not have a PDU session routing context for the old PDU session ID and the UE, the AMF does not have a PDU session routing context for the PDU session ID and the UE, the Request type IE is set to "initial request", the AMF should select an SMF with following handlings:

if the S-NSSAI IE is not included and the allowed NSSAI contains:

A) one S-NSSAI, the AMF shall use the S-NSSAI in the allowed NSSAI as the S-NSSAI;

B) two or more S-NSSAIs and the user's subscription context obtained from UDM contains only one default S-NSSAI that is included in the allowed NSSAI, the AMF shall use the default S-NSSAI in the allowed NSSAI as the S-NSSAI; or

if the DNN IE is not included, and the user's subscription context obtained from UDM:

A) contains the default DNN for the S-NSSAI, the AMF shall use the default DNN as the DNN; and

B) does not contain the default DNN for the S-NSSAI, the AMF shall use a locally configured DNN as the DNN;

iii) if the DNN selected by the network is a LADN DNN, the AMF shall determine the UE presence in LADN service area (see clause 6.2.6);

if the SMF selection is successful, the AMF should store a PDU session routing context for the PDU session ID and the UE, set the SMF ID in the stored PDU session routing context to the selected SMF ID, and forward the 5GSM message, the PDU session ID, the old PDU session ID, the S-NSSAI, the mapped S-NSSAI (if available), the DNN determined by the AMF, DNN selected by the network (if different from DNN determined by the AMF), the request type and UE presence in LADN service area (if DNN selected by the network corresponds to an LADN DNN) towards the SMF ID of the PDU session routing context; and
if the SMF selection fails, then the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);

if the AMF has a PDU session routing context for the PDU session ID and the UE, the PDU session routing context indicates that the PDU session is not an emergency PDU session, and the Request type IE is included and is set to "existing emergency PDU session", the AMF may send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);
if the AMF has a PDU session routing context for the PDU session ID and the UE, the PDU session routing context indicates that the PDU session is an emergency PDU session, and the Request type IE is included and is set to "existing PDU session", the AMF may forward the 5GSM message, the PDU session ID, the S-NSSAI (if configured in the AMF emergency configuration data), the DNN (if configured in the AMF emergency configuration data), and the request type towards the SMF identified by the SMF ID of the PDU session routing context;
if the AMF has a PDU session routing context for the PDU session ID and the UE, the Request type IE is set to "initial request", then the AMF shall perform a local release of the PDU session identified by the PDU session ID and shall request the SMF to perform a local release of the PDU session, and proceed as specified in clause 5.4.5.2.3;
if the Request type IE is set to "initial request" or "modification request", and the S-NSSAI IE contains an S-NSSAI that is not allowed by the network, then the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e), case f) or h4);
if the Request type IE is set to "existing PDU session", the AMF has a PDU session routing context for the PDU session ID and the UE, the PDU session routing context indicates that the PDU session is not an emergency PDU session, and the S-NSSAI associated with the PDU session identified by the PDU session ID is not allowed for the target access type, the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e), case f) or h4);
if the Request type IE is set to "initial request", "existing PDU session", "modification request" or "MA PDU request":

the UE is not configured for high priority access in selected PLMN or SNPN; or
the UE is configured for high priority access in selected PLMN or SNPN and service area restrictions are applicable for high priority access based on operator policy;

and the UE is in a non-allowed area or is not in an allowed area, the AMF shall send back to the UE the 5GSM message which was not forwarded, and 5GMM cause #28 "Restricted service area" as specified in clause 5.4.5.3.1 case i);

15a) if the Request type IE is set to "initial request" or "initial emergency request" and the AMF determines that the UE has registered to a PLMN via:

a satellite NG-RAN cell; or
a non-satellite NG-RAN cell where the PLMN supports selected features that are normally applied in the satellite access and the UE has indicated NonSATLSP supported,

that is not allowed to operate at the present UE location, then the AMF may send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case i1); and

if the Request type IE is set to "initial request" or "MA PDU request", the AMF is pending the receipt of a REGISTRATION REQUEST message indicating "mobility registration updating" in the 5GS registration type IE, and an emergency PDU session exists for the UE (see clause 5.4.4.3), the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);
if the timer T3447 is running and the UE supports service gap control and:

the Request type IE:

A) is set to "initial request";

B) is set to "existing PDU session"; or

C is set to "modification request" and the PDU session being modified is a non-emergency PDU session;

the UE is not configured for high priority access in selected PLMN;

iii) the current NAS signalling connection was not triggered by paging; and

mobile terminated signalling has not been sent or no user-plane resources have been established for any PDU session after the establishment of the current NAS signalling connection,

then the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);

if the AMF has a PDU session routing context for the PDU session ID and the UE, the Request type IE is not included, the UE is not configured for high priority access in selected PLMN or SNPN, and the PDU session is not an emergency PDU session, then the AMF shall forward the 5GSM message, and the PDU session ID IE towards the SMF identified by the SMF ID of the PDU session routing context with:

an exemptionInd attribute indicating "message was exempted from the DNN based congestion activated in the AMF" as specified in 3GPP TS 29.502 [20A], if DNN based congestion control is activated for the selected DNN;
an exemptionInd attribute indicating "message was exempted from the S-NSSAI and DNN based congestion activated in the AMF" as specified in 3GPP TS 29.502 [20A], if S-NSSAI and DNN based congestion control is activated for the selected S-NSSAI and the selected DNN; or

iii) an exemptionInd attribute indicating "message was exempted from the S-NSSAI only based congestion activated in the AMF" as specified in 3GPP TS 29.502 [20A], if S-NSSAI only based congestion control is activated for the selected S-NSSAI;

if the Request type IE is set to "MA PDU request" and the S-NSSAI IE contains an S-NSSAI that is not allowed by the network on neither access, then the AMF shall send to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f);
if the Request type IE is set to "initial request" and the UE is registered for emergency services over the current access, then the AMF may send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e) or case f); and
if the Request type IE is set to "existing PDU session", the UE is attempting to transfer a PDU session from 3GPP access to non-3GPP access, and the PDU session is associated with control plane only indication then the AMF shall send back to the UE the 5GSM message which was not forwarded as specified in clause 5.4.5.3.1 case e).
if the Request type IE is set to "MA PDU request" and the UE requested DNN corresponds to an LADN DNN, the AMF shall send back to the UE the 5GSM message which was not forwarded and 5GMM cause #90 "payload was not forwarded" as specified in clause 5.4.5.3.1 case h3).
if the Request type IE is set to "initial request", the UE requested DNN corresponds to an LADN DNN, and the MA PDU session information IE is included, the AMF shall not forward the MA PDU session information towards the SMF.
if the Request type IE is set to "modification request", the DNN associated with the PDU session corresponds to an LADN DNN, and MA PDU session information IE is included, the AMF shall not forward the MA PDU session information towards the SMF.

If the Payload container type IE is set to "SMS" and:

the AMF does not have an SMSF address associated with the UE;
the AMF cannot forward the content of the Payload container IE to the SMSF associated with the SMSF address available in the AMF; or
the AMF determines that the UE has registered to a PLMN via:

a satellite NG-RAN cell; or
a non-satellite NG-RAN cell where the PLMN supports selected features that are normally applied in the satellite access and the UE has indicated NonSATLSP supported

that is not allowed to operate at the present UE location;

then the AMF shall abort the procedure.

If the Payload container type IE is set to "LTE Positioning Protocol (LPP) message container" or "SLPP message container" and:

the Additional information IE is not included in the UL NAS TRANSPORT message;
the AMF cannot forward the content of the Payload container IE to the LMF associated with the routing information included in the Additional information IE; or
the AMF determines that the UE has registered to a PLMN via:

a satellite NG-RAN cell; or
a non-satellite NG-RAN cell where the PLMN supports selected features that are normally applied in the satellite access and the UE has indicated NonSATLSP supported

that is not allowed to operate at the present UE location;

then the AMF shall abort the procedure.

If the Payload container type IE is set to "UE policy container" and:

the AMF does not have a PCF address associated with the UE;
the AMF cannot forward the content of the Payload container IE to the PCF associated with the PCF address available in the AMF; or
the AMF determines that the UE has registered to a PLMN via:

a satellite NG-RAN cell; or
a non-satellite NG-RAN cell where the PLMN supports selected features that are normally applied in the satellite access and the UEhas indicated NonSATLSP supported

that is not allowed to operate at the present UE location;

then the AMF shall abort the procedure.

If the Payload container type IE is set to "Location services message container" and:

the Additional information IE is included in the UL NAS TRANSPORT message and the AMF cannot forward the content of the Payload container IE to an LMF associated with the routing information included in the Additional information IE;
the AMF determines that the UE has registered to a PLMN via:

a satellite NG-RAN cell; or
a non-satellite NG-RAN cell where the PLMN supports selected features that are normally applied in the satellite access and the UE has indicated NonSATLSP supported

that is not allowed to operate at the present UE location;

the AMF determines that the payload container content is related to PRU and the UE has not a valid PRU subscription information; or
any combination of bullets 1 to 3,

then the AMF shall abort the procedure.

If the Payload container type IE is set to "SMS", "LTE Positioning Protocol (LPP) message container", "SLPP message container" or "Location services message container" and:

the timer T3447 is running and the UE supports service gap control;
the UE is not configured for high priority access in selected PLMN;
the current NAS signalling connection was not triggered by paging; and
mobile terminated signalling has not been sent or no user-plane resources have been established for any PDU session after the establishment of the current NAS signalling connection,

then the AMF shall abort the procedure.

NOTE: In this state the N1 NAS signalling connection can be released by the network.

If the Payload container type IE is set to "CIoT user data container" and:

the AMF does not have a PDU session routing context for the PDU session ID and the UE; or
the AMF unsuccessfully attempted to forward the user data container and the PDU session ID,

then the AMF may send back to the UE the CIoT user data container which was not forwarded as specified in clause 5.4.5.3.1 case l1).

If the Payload container type IE is set to "CIoT user data container" and:

the timer T3447 is running and the UE supports service gap control;
the UE is not configured for high priority access in selected PLMN;
the current N1 NAS signalling connection was not triggered by paging; and
mobile terminated signalling has not been sent or no user-plane resources have been established for any PDU session after the establishment of the current NAS signalling connection,

then the AMF shall send back to the UE the CIoT user data container which was not forwarded as specified in clause 5.4.5.3.1 case l2).

If the Payload container type IE is set to "SOR transparent container", "UE parameters update transparent container", or "Service-level-AA container", and the AMF determines that the UE has registered to a PLMN via:

a satellite NG-RAN cell; or
a non-satellite NG-RAN cell where the PLMN supports selected features that are normally applied in the satellite access and the UE has indicated NonSATLSP supported

that is not allowed to operate at the present UE location, then the AMF shall abort the procedure.

If the Payload container type IE is set to "UPP-CMI container" and:

the AMF cannot forward the content of the Payload container IE to the LMF associated with the routing information included in the Additional information IE; or
the AMF determines that the UE has registered to a PLMN via:

a satellite NG-RAN cell; or
a non-satellite NG-RAN cell where the PLMN supports selected features that are normally applied in the satellite access and the UE has indicated NonSATLSP supported

that is not allowed to operate at the present UE location;

then the AMF shall abort the procedure.