Section: 4.17.6.2 SMF provisioning of UPF instances using NRF
Content: This procedure applies when a SMF wants to get informed about UPFs available in the network and supporting a list of parameters. Figure 4.17.6.2-1: SMF provisioning of UPF instances using NRF procedure The following takes place when an SMF expects to be informed of UPFs available in the network: 1 The SMF issues a Nnrf_NFManagement_NFStatusSubscribe Service Operation providing the target UPF Provisioning Information it is interested in. 2 The NRF issues Nnrf_NFManagement_NFStatusNotify with the list of all UPFs that currently meet the SMF subscription. This notification indicates the subset of the target UPF Provisioning Information that is supported by each UPF. The following takes place when a new UPF instance is deployed: 3 At any time a new UPF instance is deployed. 4 The UPF instance is configured with the NRF identity to contact for registration and with its UPF Provisioning Information. An UPF is not required to understand the UPF Provisioning Information beyond usage of this information to register in step 5. 5 The UPF instance issues an Nnrf_NFManagement_NFRegister Request operation providing its NF type, the FQDN or IP address of its N4 interface and the UPF Provisioning Information configured in step 4. 6. Alternatively (to steps 4 and 5) OAM registers the UPF on the NRF indicating the same UPF Provisioning Information as provided in step 5. This configuration mechanism is out of scope of this specification. 7. Based on the subscription in step 1, the NRF issues Nnrf_NFManagement_NFStatusNotify to all SMFs with a subscription matching the UPF Provisioning Information of the new UPF