B.5 Enhancements for dnn NFProfile Attribute and Discovery Query Parameter

NRF supports dnn attribute that represents the Data Network Name (DNN). DNN comprises of the Network Identifier and Operator Identifier.

Until 24.2.x release, when dnn attribute was provided during NFManagement and NFDiscover service operations, NRF performed validations for null or empty values. NRF also supported exact matching of dnn query attribute value with the dnn attribute present in the registered NFProfile for NFDiscover service operations.

From 24.3.x releases, NRF performs the validations for the dnn attribute, as per 3GPP TS 29.571 v16.7. These validations are added for the NF Types SMF, UPF, PCF, and BSF (that is, smfInfo,smfInfoList, upfInfo, pcfInfo, and bsfInfo).

Note:

The attributes for upfInfoList, pcfInfoList, and bsfInfoList are not supported by NRF.
  • Maximum length of DNN is 100 Octets.
  • DNN Structure = <Label>.<Label>.<Label>. Label should only contain (A-Z), (a-z), (0-9), '-'.
  • Network Identifier structure is mandatory in DNN.

    Validations for Network Identifier:

    • maximum length can be 63 Octets
    • cannot start with {"rac","lac","sgsn","rnc"}
    • cannot end with {"gprs"}
    • cannot take value {"*"}
  • Operator Identifier structure is optional in DNN.

    Validations for Operator Identifier:

    • The Access Point Name (APN) Operator Identifier is composed of three labels. The last label (= domain) shall be "gprs".
    • The first and second labels together identifies the PLMN.

      Format: "mnc<MNC>.mcc<MCC>.gprs", <MNC> of 3 digits , <MCC> of 3 digits.

      • The format should be strictly followed. Any change in the formatted value will result in considering the whole dnn value as Network Identifier.
      • Any other value of mcc and mnc comprising of anything else like alphabets, negative value, or hyphen(-) will be rejected.

        Consumer NF should send the MNC in 3 digits to NRF.

        Note: If there are only 2 significant digits in the MNC, one "0" digit must be added at the left side by Consumer NF to fill the 3 digits coding of MNC in the APN Operator Identifier.

        For example: If the APN Operator Identifier for MCC 345 and MNC 12, then Consumer NF sends MNC as 012 in the DNS "mnc012.mcc345.gprs" to NRF.

Examples:

  • Following are the examples of valid dnn values:
    • province1.mnc012.mcc345.gprs

      Here, province1 is Network Identifier and mnc012.mcc345.gprs is Operator Identifier.

    • ggsn-cluster-A.provinceB.mnc012.mcc345.gprs

      Here, ggsn-cluster-A.provinceB is Network Identifier and mnc012.mcc345.gprs is Operator Identifier.

  • Following are the examples of invalid dnn values along with their rejection reasons:
    • province_A, provinc*A.mnc012.mcc345.gprs

      Here, these would be rejected as both the values contain a label having a character ( _ and * respectively ) that is not in permissible list of characters (A-Z), (a-z), (0-9), '-'.

    • province1.gprs, province-A.gprs.mnc012.mcc345.gprs

      Here, these would be rejected as all the values have their network identifier part ending with gprs.

    • lac.province.mnc012.mcc345.gprs, race-province, rncabc.provinceA.mnc012.mcc345.gprs, and sgsn

      Here, these would be rejected as all of the values have their network identifier starting with one of the following {"rac","lac","sgsn","rnc"}.

As per 3GPP TS 29.510 v16.7, the dnn attribute present in the discovery query is considered as a match with a dnn attribute present in the registered NFProfile during the following scenarios:
  • Both the dnn attributes contain the same Network Identifier and Operator Identifier.
  • Both the dnn attributes contain the same Network Identifier and none contains an Operator Identifier.
  • The dnn attribute in the discovery query contains only the Network Identifier and the DNN value in the registered NF Profile contains both the Network Identifier and Operator Identifier, and both contain the same Network Identifier.
  • The dnn attribute in the discovery query contains both the Network Identifier and Operator Identifier, the dnn value in the NF Profile contains the Network Identifier only, both contain the same Network Identifier and the Operator Identifier matches one PLMN of the NF (that is, plmnList of the NF Profile).

Note:

Prior to 24.3.0 release, NRF was not performing dnn validations. From 24.3.0 release, dnn validations are added for NFManagement and NFDiscover service operations as per 3GPP defined format. The following points should be considered while performing the validations:

  • Prior upgrading NRF to 24.3.x, in case NRF database contains NFProfiles with dnn attribute and dnn attribute value is not as per 3GPP defined format, NFs should update their NFProfiles with correct dnn format (as defined in 3GPP TS 23.003 v16.8 Section 9A). NFProfiles can be updated using NFRegister or NFUpdate (PUT or PATCH) service operations.
  • Post upgrading NRF to release 24.3.x, in case there are still NFProfiles with dnn attribute value not as per 3GPP defined format, then NFProfile processing is performed for NRF service operations as follows:
    • NFRegister (PUT): NFs are allowed to re-register with dnn attribute value as per 3GPP defined format.
    • NFUpdate (PUT): NFs are allowed to update the dnn attribute value as per 3GPP defined format.
    • NFUpdate (PATCH): NFs are not allowed to update the dnn attribute value. NRF rejects the request with status code as 400 bad request.
    • NFUpdate (Heartbeat): NFs are allowed to do heartbeat for such NFProfiles as per 3GPP specifications.
    • NFDiscover:
      • NFDiscover query with dnn attribute value if not as per 3GPP defined format, is rejected by NRF.
      • The NFProfiles in the database having invalid dnn value format will be ignored while filtering NFProfiles based on dnn query attribute.
      • The NFProfiles in the database having invalid dnn value format will be included in the NFDiscover response if dnn is not present in the discovery query if other attributes present in the query matches as per 3GPP NRF specifications.
      • The NFProfiles in the database having invalid dnn value format for Operator Identifier but Network Identifier value is in correct format. dnn attribute is present in the discovery query with matching network identifier and no operator identifier. In this case, such NFProfiles will be included in the NFDiscover response.
    • NFStatusNotify: NRF sends notifications for NFUpdate and NFRegister PUT service operations with the updated NFProfiles. As NFUpdate (Patch) request is rejected, NRF does not send notifications for the service operation.