Section: 6.2.6 NRF 6.2.6.1 General
Content: The Network Repository Function (NRF) supports the following functionality: - Supports service discovery of NRF services and their endpoint addresses by the NRF bootstrapping service. - Supports service discovery function. Receive NF Discovery Request from NF instance or SCP, and provides the information of the discovered NF instances (be discovered) to the NF instance or SCP. - Supports P-CSCF discovery (specialized case of AF discovery by SMF). - Maintains the NF profile of available NF instances and their supported services. - Maintains SCP profile of available SCP instances. - Supports SCP discovery by SCP instances. - Notifies about newly registered/updated/ deregistered NF and SCP instances along with its potential NF services to the subscribed NF service consumer or SCP. - Maintains the health status of NFs and SCP. In the context of Network Slicing, based on network implementation, multiple NRFs can be deployed at different levels (see clause 5.15.5): - PLMN level (the NRF is configured with information for the whole PLMN), - shared-slice level (the NRF is configured with information belonging to a set of Network Slices), - slice-specific level (the NRF is configured with information belonging to an S-NSSAI). In the context of roaming, multiple NRFs may be deployed in the different networks (see clause 4.2.4): - the NRF(s) in the Visited PLMN (known as the vNRF) configured with information for the visited PLMN. - the NRF(s) in the Home PLMN (known as the hNRF) configured with information for the home PLMN, referenced by the vNRF via the N27 interface.