NF Dictionary (Network Function)¶
A dictionary for looking up each 5GC Network Function (NF) by its formal name, role, provided APIs, and related Interfaces. First get a rough idea from the one-line role description, then proceed to the individual pages or related Specs for details.
Related: Interface Dictionary / Protocol Dictionary / Registration chapter
NF List¶
| NF | Formal Name | Role (1 line) | Main Provided APIs | Related Interfaces | Individual Page | Main Spec |
|---|---|---|---|---|---|---|
| AMF | Access and Mobility Management Function | Terminates N1/N2; manages registration, connection, and mobility | Namf (Communication, EventExposure, etc.) | N1, N2, N8, N11, N12, N14, N15 | AMF | TS 23.501 §6.2.1 |
| AUSF | Authentication Server Function | Authentication (5G-AKA / EAP-AKA') server | Nausf (UEAuthentication) | N12, N13 | AUSF | TS 23.501 §6.2.8 |
| UDM | Unified Data Management | Subscriber data management and authentication information generation | Nudm (UECM, SDM, UEAU, etc.) | N8, N10, N13 | UDM | TS 23.501 §6.2.7 |
| SMF | Session Management Function | PDU session management, UPF control (N4) | Nsmf (PDUSession, EventExposure, etc.) | N4, N7, N10, N11 | SMF | TS 23.501 §6.2.2 |
| UPF | User Plane Function | User plane processing (packet forwarding, QoS enforcement, charging measurement) | — (controlled by SMF over N4) | N3, N4, N6, N9 | UPF | TS 23.501 §6.2.3 |
| UDR | Unified Data Repository | Data storage repository for subscriber, policy, etc. data | Nudr (DataRepository) | N35, N36, N37 | UDR | TS 23.501 §6.2.11 |
| NRF | Network Repository Function | NF registration, discovery, and selection support | Nnrf (NFManagement, NFDiscovery) | SBI | NRF | TS 23.501 §6.2.6 |
| NSSF | Network Slice Selection Function | Network slice selection support (NSSAI resolution) | Nnssf (NSSelection, NSSAIAvailability) | N22 | NSSF | TS 23.501 §6.2.14 |
| PCF | Policy Control Function | Policy control (QoS, charging, access control rules) | Npcf (AMPolicyControl, SMPolicyControl, etc.) | N5, N7, N15 | PCF | TS 23.501 §6.2.4 |
| CHF | Charging Function | Charging (online/offline) function | Nchf (ConvergedCharging, etc.) | N40 | CHF | TS 32.290 (CHF has no clause in TS 23.501 §6.2) |
| NEF | Network Exposure Function | Capability exposure to external AFs and information mediation | Nnef | N33 | NEF | TS 23.501 §6.2.5 |
| NWDAF | Network Data Analytics Function | Network data analytics and prediction | Nnwdaf (AnalyticsInfo, EventsSubscription) | SBI | NWDAF | TS 23.501 §6.2.18 |
| BSF | Binding Support Function | Manages binding information between sessions and PCF | Nbsf (Management) | SBI | BSF | TS 23.503 (BSF has no clause in TS 23.501 §6.2) |
| SMSF | Short Message Service Function | SMS delivery function via NAS | Nsmsf (SMService) | N20, N21 | SMSF | TS 23.501 §6.2.13 |
| SEPP | Security Edge Protection Proxy | Edge protection of inter-PLMN SBI signaling (N32) | — | N32 | SEPP | TS 23.501 §6.2.17 |
| SCP | Service Communication Proxy | Mediation of inter-NF SBI communication within a PLMN (indirect communication). Route control and delegated Discovery in Model C/D | — | SBI | SCP | TS 23.501 (communication models A–D; clause number to be confirmed) |
| AF | Application Function | Application-side function (integrates via NEF or directly with PCF) | — | N5 (when directly connected to PCF) | AF | TS 23.501 §6.2.10 |
| 5G-EIR | 5G Equipment Identity Register | Checks the status of the terminal's equipment identifier PEI (IMEI, etc.) (blacklist lookup). Queried by the AMF | N5g-eir (EquipmentIdentityCheck) | SBI | 5G-EIR | TS 23.501 (§6.2-series clause number to be confirmed) |
| GMLC | Gateway Mobile Location Centre | The point of contact for external LCS clients. Authorizes location requests and discovers the serving AMF | Ngmlc (to be confirmed) | Le, SBI | — | TS 23.273 / TS 23.501 (clause number to be confirmed) |
| LMF | Location Management Function | Positioning computation NF. Collects measurements via LPP (UE)/NRPPa (RAN) and computes location | Nlmf (to be confirmed) | NL series (AMF⇔LMF) | — | TS 23.273 / TS 23.501 (clause number to be confirmed) |
About Clause Numbers
The TS 23.501 §6.2-series clause numbers for NFs are the values finalized in the ETSI published version (TS 123 501 V17.x, Rel-17). The core NFs of 6.2.1–6.2.19 (AMF–SCP) were numbered in Rel-15 and have not been changed in Rel-16/17 since. Note that CHF does not have an independent clause in TS 23.501 §6.2 (it is defined in charging-series Specs such as TS 32.290), and BSF likewise has no clause in §6.2 and is defined in TS 23.503 (PCC framework). GMLC / LMF are NFs for location services (LCS), primarily grounded in TS 23.273 (positioning stage 2). Their individual pages have not been created; for the overall procedure, refer to Location Service (LCS). The SBI service names of GMLC/LMF (Ngmlc/Nlmf) and the formal NL-series numbers for AMF⇔LMF differ by Release and are therefore marked to be confirmed.