Section: 5.2.16.3.3 Nnssf_NSSAIAvailability_Notify service operation
Content: Service operation name: Nnssf_NSSAIAvailability_Notify Description: This service operation enables the NSSF to update a NF Service Consumer (e.g. AMF) with any S-NSSAIs restricted per validity time, or per TA and if needed subsequently lift any restriction per TA. This service operation also enables the NSSF to notify to the NF Service Consumer (e.g. AMF or NSSF in the VPLMN) that an S-NSSAI has to be replaced by an Alternative S-NSSAI or a Network Slice instance should be replaced. Inputs, Required: Subscription Correlation ID. Inputs, Conditional Required: If this service operation is invoked by subscription for changes in the status of the NSSAI availability information, then the following inputs are required: - a list of TAIs and the S-NSSAIs for which the status is changed (restricted/unrestricted) per each TAI. If this service operation is invoked by subscription for event notification for Network Slice Replacement, then the following inputs are required: - For replacement of an S-NSSAI of the serving PLMN: an Alternative S-NSSAI and the corresponding mapping to the S-NSSAI to be replaced. - For replacement of an HPLMN S-NSSAI: an Alternative S-NSSAI and the corresponding mapping to the S-NSSAIs of the HPLMN, PLMN ID. - For termination of the Network Slice replacement: 1) indication to stop the Network Slice replacement for new UEs; or 2) indication to terminate the Network Slice replacement and move back the UEs and PDU Sessions from the Alternative S-NSSAI to the S-NSSAI. If this service operation is invoked by subscription for event notification for Network Slice Instance Replacement, then the following inputs are required: - The S-NSSAI(s) and NSI ID(s) for which the status is changed (e.g. congested or no longer available). If this service operation is invoked by subscription for event notification for update of slice validity time, then the following inputs are required: - The S-NSSAI(s) and associated validity time for each S-NSSAI. Inputs, Optional: - NSI IDs in the S-NSSAI for which the status is changed (restricted/unrestricted) per each TAI. If this service operation is invoked by subscription for event notification for Network Slice Replacement or Network Slice Instance Replacement, then the following inputs are optional: - For replacement due to congestion: congestion mitigation information. Outputs, Required: None. Outputs, Optional: None.