Section: 5.8.2.17 Data exposure via Service Based interface
Content: The UPF may expose information by means of UPF Event Exposure service as described in TS 23.502[ Procedures for the 5G System (5GS) ]  [3] clause 5.2.26.2, via a service-based interface directly. The NF consumers, which may receive UPF event notifications, are AF/NEF, TSNAF/TSCTSF and NWDAF/DCCF/MFAF. When the UPF supports the data exposure via the service based interface, it may register its NF profile to the NRF including the UPF Event Exposure services and the related Event ID(s). For data collection from UPF (see clause 4.15.4.5 of TS 23.502[ Procedures for the 5G System (5GS) ]  [3]), NF consumers do the subscription to the UPF directly or indirectly via SMF. A n NF consumer may subscribe to the UPF Event Exposure service directly only for data collected for "any UE" e.g. to collect user data usage information for NWDAF NF Load analytic (see clause 6.5 of TS 23.288[ Architecture enhancements for 5G System (5GS) to support network data analytics services ]  [86]) and if the subscription is not including any of the following parameters: AoI, traffic filtering, BSSID/SSID and Application ID. To alleviate the load of UPF due to frequent event notification, the event subscription may include Reporting suggestion information. The Reporting suggestion information includes Report urgency and Reporting window information. Reporting urgency information represents whether this event report can be delay tolerant, i.e. the event report can be delayed. If the Reporting urgency information indicates "delay tolerant", the Reporting window is also provided, which defines the last valid reporting time, and UPF shall report the detected event before the last valid time. Per Reporting suggestion information UPF can concatenate several notification messages to the same notification endpoint in one notification message. The UPF may also expose UE information by means of the Nupf_GetUEPrivateIPaddrAndIdentifiers service as described in TS 23.502[ Procedures for the 5G System (5GS) ]  [3] clause 5.2.26.3. An UPF which is deployed with NAPT (Network Address Port Translation) functionality may support to provide the 5GC UE IP address to NEF based on NEF request containing public IP address and port number using the Nupf_GetUEPrivateIPaddrAndIdentifiers service as described in clause 4.15.10 of TS 23.502[ Procedures for the 5G System (5GS) ]  [3] for AF specific UE ID retrieval.