ons in the 5G core: 5G network concepts NWDAF Figure 2.10 - AF reference points The role of the AF is relevant in non-roaming cases. The AF can send requests to influence the SMF routing decisions for the traffic in a PDU session. The AF may also influence the UP selection by the SMF. The AF interacts with the PCF via N5 and hence can update policies related to an ongoing PDU session. The UDR The UDR serves as the data store for the subscription information for UE. It helps in the storage and retrieval of subscription data by the UDM. It helps with storage and the retrieval of policy data for the PCF. It also stores and retrieves structured data for exposure via the NEF: Figure 2.11 - UDF reference points End-to-End Architecture Components, Concepts, Security, and Transport It stores PFDs for application detection. It also stores and retrieves NF group IDs corresponding to a subscriber. It must be noted that the UDR is an intra-PLMN NF and it will store and retrieve information only for the NFs within the same PLMN. The SMSF The SMSF is responsible for providing the functionality of supporting SMS over NAS. It performs SMS management subscription data checking and conducts SMS delivery accordingly. It relays the message from the device toward the SMS-GMSC, IWMSC, or SMS router, and vice versa: NG-RAN SMS over NAS Figure 2.12 - SMSF reference architecture It also generates CDRs related to the SMS. It can perform lawful interception and interacts with the AMF and the SMS-GMSC for the notification procedure that communicates whether the UE is available or unavailable for SMS transfer. It also notifies the SMS-GMSC to inform the UDM when the UE is unavailable to receive SMS. The NSSF Network slicing is a concept introduced with 5G networks. Network slicing allows the operator to design their physical infrastructure differently for different use cases. As an example, a URLLC use case, an enhanced broadband use case, and an IoT use case can all be assigned different types of infrastructure (hardware or networking) base