Section: 4.15.4.5.3 Information flow for UPF event exposure service for any UE
Content: Figure 4.15.4.5.3-1: UPF Information Exposure to the UPF event consumer (e.g. NWDAF) of any UE scenario 1. (For the case when the UPF event consumer is NWDAF) The analytics consumer sends a request to the NWDAF for analytics on any UE. The analytics consumer provides the value "any UE" in the Target of Analytics Reporting. Analytics Filter Information optionally contains DNN, S-NSSAI, Area of Interest, Application server IP address/FQDN, APP ID, DNAI, etc. 2. (Optional and only when the UPF event consumer is NWDAF) If the Analytic Filter Information does not contain DNN/S-NSSAI, but only includes application server IP address/FQDN, the NWDAF should first obtain the DNAI from NEF. The NWDAF invokes Nnef_DNAIMapping_Subscribe service to request the DNAI information. The request includes EAS IP/IP range and/or FQDN. 3. (Conditional, if step 2 took place) The NEF determines the suitable DNAI(s) and provides them to NWDAF. 4. The UPF event consumer triggers the SMF(s)/UPF(s) discovery to NRF by Nnrf_NFDiscovery_Request providing the DNN, S-NSSAI, DNAI etc. This procedure is to discover the related SMF(s)/UPF(s) associated with any UE and support the indicated DNAI. Either SMF(s) or UPF(s) are discovered depending on whether the subscription request to UPF events meets the criteria for direct subscription to UPF as defined in clause 5.8.2 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]). 5. The NRF provides Nnrf_NFDiscovery_Response that may refer to several SMFs/UPFs. 6. (Option 1) If the subscribed UPF events needs the SMF(s) to do a third-party subscription onto UPF (as defined in clause 5.8.2 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]), the same procedure as Indirect subscription via several SMFs (steps 3 - 5 in Figure 4.15.4.5.2-1(for single UE)) takes place via each discovered SMF. 7. (Option 2) If the subscribed UPF events allows to directly subscribe to UPF (as defined in clause 5.8.2 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2]), the UPF event consumer (e.g. NWDAF) triggers the Nupf_EventExposure_Subscribe to all discovered UPFs. The information included in the subscription is as described in step 3 in clause 4.15.4.5.2. 8. Each of the UPFs invokes Nupf_EventExposure_Notify service operation directly to the UPF event consumer (e.g. NWDAF).