Nsmf_NIDD Delivery Request/Response Figure 3.12 - Services produced by the SMF REST in 5G TheNsmf_PDUSession_ContextRequest service operation is used by consumers to request an SM context for a particular subscriber. TheNsmf_PDUSession_ContextPushRequest is leveraged by the SMF to push SM context to another SMF, which acts as a consumer. This is used mainly during roaming cases. The Nsmf_PDUSession_SendMOData service operation is used by the AMF to send mobile-originating data that it has received from the UE as part of the NAS procedure to the SMF. The Nsmf_PDUSession_TransferMOData service operation is used by the visited or intermediate SMF to forward the mobile-originated data that it received from UE as a part of a NAS message to the home SMF. The Nsmf_PDUSession_TransferMTData service operation is used by the home SMF to transfer MT data from the NEF to the visited or intermediate SMF. The Nsmf_EventExposure service is responsible for providing events related to PDU sessions to its consumer network function. This allows NFs to subscribe to or unsubscribe from a particular event relating to the PDU session. The Nsmf_NIDD_Delivery service operation is used by the consumer network function to deliver unstructured data from itself to the SMF. UDM services As you saw in Chapter 2, the UDM is involved with subscriber information, SO let's take a deeper look at what this information's contents are. It's an easy guess that it would include a subscriber identifier, such as a SUPI, but what are the associated details of this SUPI? Let's look at an exhaustive list of user details, per Release 16,23.502. Building Blocks - Cloud Native Infrastructure GPSI List SoR Update indicator for emergency registration For emergency PDU session Id Internal group ID-list Network slicing subscription change indicator Secondary authentication indication Subscribed-UE-AMBR Tracing requirements DN-AAA server UR IP address allocation indication Subscribed-S-NSSAls Inclusion of NSSAI in RRC connection establishment allowed DN-AAA server a