The purpose of the AMF Configuration Update procedure is to update application level configuration data needed for the NG-RAN node and AMF to interoperate correctly on the NG-C interface. This procedure does not affect existing UE-related contexts, if any. The procedure uses non UE-associated signalling.
The AMF initiates the procedure by sending an AMF CONFIGURATION UPDATE message including the appropriate updated configuration data to the NG-RAN node. The NG-RAN node responds with an AMF CONFIGURATION UPDATE ACKNOWLEDGE message to acknowledge that it successfully updated the configuration data. Unless stated otherwise, if an information element is not included in the AMF CONFIGURATION UPDATE message, the NG-RAN node shall interpret that the corresponding configuration data is not changed and shall continue to operate the NG-C interface with the existing related configuration data.
If the
PLMN Support List IE is included in the AMF CONFIGURATION UPDATE message, the NG-RAN node shall overwrite the whole list of supported PLMN/SNPN Identities and the corresponding list of AMF slices and, if present, other associated information for each PLMN/SNPN Identity and use the received values for further network slice selection and AMF selection.
If the
AMF TNL Association to Add List IE is included in the AMF CONFIGURATION UPDATE message, the NG-RAN node shall, if supported, use it to establish the TNL association(s) with the AMF. If the
AMF TNL Association to Add List IE is included in the AMF CONFIGURATION UPDATE message, and if the
AMF TNL Association Address IE does not include the
Port Number IE, the NG-RAN node shall assume that port number value 38412 is used for the endpoint. The NG-RAN node shall report to the AMF, in the AMF CONFIGURATION UPDATE ACKNOWLEDGE message, the successful establishment of the TNL association(s) with the AMF as follows:
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A list of successfully established TNL associations shall be included in the AMF TNL Association Setup List IE;
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A list of TNL associations that failed to be established shall be included in the AMF TNL Association Failed to Setup List IE.
If the AMF CONFIGURATION UPDATE message includes the
AMF TNL Association to Remove List IE, the NG-RAN node shall, if supported, initiate removal of the TNL association(s) indicated by AMF TNL endpoint(s) and NG-RAN node TNL endpoint(s) if the
TNL Association Transport Layer Address NG-RAN IE is present, or the TNL association(s) indicated by AMF TNL endpoint(s) if the
TNL Association Transport Layer Address NG-RAN IE is absent:
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if the received AMF TNL Association Address IE includes the Port Number IE, the AMF TNL endpoint is identified by the Endpoint IP Address IE and the Port Number IE. Otherwise, the AMF TNL endpoints correspond to all AMF TNL endpoints identified by the Endpoint IP Address IE and any port number(s).
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if the received TNL Association Transport Layer Address NG-RAN IE includes the Port Number IE, the NG-RAN node TNL endpoint is identified by the Endpoint IP Address IE and the Port Number IE. Otherwise, the NG-RAN node TNL endpoints correspond to all NG-RAN node TNL endpoints identified by the Endpoint IP Address IE and any port number(s).
If the
AMF Name IE is included in the AMF CONFIGURATION UPDATE message, the NG-RAN node shall overwrite the previously stored AMF name and use it to identify the AMF.
If the AMF CONFIGURATION UPDATE message includes the
AMF Name IE, the NG-RAN node may store it or update this IE value if already stored, and use it as a human readable name of the AMF. If the AMF CONFIGURATION UPDATE message includes the
Extended AMF Name IE, the NG-RAN node may store it or update this IE value if already stored, and use it as a human readable name of the AMF and shall ignore the
AMF Name IE if also included.
If the
Served GUAMI List IE is included in the AMF CONFIGURATION UPDATE message, the NG-RAN node shall overwrite the whole list of GUAMIs served by the AMF by the new list and use the received values for further AMF management and AMF selection as defined in
TS 23.501.
If the
Relative AMF Capacity IE is included in the AMF CONFIGURATION UPDATE message, the NG-RAN node may use it as defined in
TS 23.501.
If the
AMF TNL Association to Update List IE is included in the AMF CONFIGURATION UPDATE message the NG-RAN node shall, if supported, update the TNL association(s) indicated by the received AMF Transport Layer information towards the AMF:
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if the received AMF TNL Association Address IE includes the Port Number IE, the AMF TNL endpoint is identified by the Endpoint IP Address IE and the Port Number IE. Otherwise, the AMF TNL endpoints correspond to all AMF TNL endpoints identified by the Endpoint IP Address IE and any port number(s).
If the
TNL Association Usage IE or the
TNL Address Weight Factor IE is included in the
AMF TNL Association to Add List IE or the
AMF TNL Association to Update List IE, the NG-RAN node shall, if supported, consider it as defined in
TS 23.502.
If the
NID IE within the
NPN Support IE is included within a
PLMN Support Item IE in the AMF CONFIGURATION UPDATE message, the NG-RAN node shall consider that the AMF supports the SNPN identified by the
PLMN Identity IE and the
NID IE.
If the
Onboarding Support IE is also included within the
same PLMN Support Item IE, the NG-RAN node shall, if supported, consider that the AMF supports UE onboarding for the identified SNPN, as specified in
TS 23.501.
If the NG-RAN node cannot accept the update, it shall respond with an AMF CONFIGURATION UPDATE FAILURE message and appropriate cause value.
If the
Time to Wait IE is included in the AMF CONFIGURATION UPDATE FAILURE message, the AMF shall wait at least for the indicated time before reinitiating the AMF Configuration Update procedure towards the same NG-RAN node.
If the AMF receives neither an AMF CONFIGURATION UPDATE ACKOWLEDGE nor an AMF CONFIGURATION UPDATE FAILURE message, the AMF may reinitiate the AMF Configuration Update procedure towards the same NG-RAN node provided that the content of the new AMF CONFIGURATION UPDATE message is identical to the content of the previously unacknowledged AMF CONFIGURATION UPDATE message.