Section: 5.2.21.2.4 Nnsacf_NSAC_NumOfPDUsUpdate service operation
Content: Service Operation name: Nnsacf_NSAC_NumOfPDUsUpdate Description: Updates the number of PDU Sessions established on a network slice (e.g. increase or decrease). Also, if the number of PDU Sessions on the network slice is to be increased, the NSACF first checks whether the number of the PDU Sessions on that network slice has reached the maximum number of PDU Sessions per network slice. If the maximum number of PDU Sessions on the network slice has already been reached, the PDU Session Establishment procedure is rejected. Inputs, Required: S-NSSAI, UE ID, PDU Session ID, Access Type, update flag. The S-NSSAI parameter is the network slice for which the number of PDU Sessions established on a network slice is to be updated. In the LBO roaming case, the corresponding mapped S-NSSAI of the HPLMN is also included. The UE ID parameter is used by the NSACF to maintain a list of UE IDs that has established PDU sessions with the network slice. PDU Session ID parameter is used by the NSACF to maintain for each UE ID, the PDU Session ID(s) for established PDU Sessions. The Access Type parameter indicates over which access network type the PDU Session is established. In the case of MA PDU Session, one or multiple Access Types may be included for a PDU Session ID. The update flag input parameter indicates 'increase', 'decrease' or 'update' as specified in clause 4.2.11.4. Inputs, Optional: NSAC admission mode, PLMN ID. NSAC admission mode applies to inbound roamers. It is included by NF consumer to indicate applicable NSAC admission mode in VPLMN. Its values can be VPLMN NSAC admission mode, or VPLMN with HPLMN assistance NSAC admission mode. The PLMN ID is the serving PLMN of the UE. Inputs, Conditional: The SMF NSAC service area is included in a centralized NSAC architecture, if applicable. Outputs, Required: Result indication, Access Type. The Result indication parameter contains the outcome of the update and check operation in the NSACF and may indicate one of the values 'maximum number of PDU Sessions for the S-NSSAI not reached' or 'maximum number of PDU Sessions for the S-NSSAI reached'. The Access Type parameter is associated with the Result indication parameter. Outputs, Optional: Updated local maximum number of PDUs. This parameter is returned only by a primary NSACF.