5G Network Functions And APIs

Question 1

5G-EIR

Answer 1

5G Equipment Identity Register

Check if device is on black list or not based on the Permanent Equipment Identifier (PEI)

Question 2

LMF

Answer 2

Location Management Function

Request location for a UE using location measurements from the UE or the NG RAN

Question 3

NSSF

Answer 3

Network Slice Selection Function
Determines the allowed and configured NSSAIs and compares to the S-NSSAIs
Determine the AMF set for network slices

Question 4

AUSF

Answer 4

Authentication Server Function
Subscriber authentication for 5G network and untrusted non-3GPP access
Retrieves authentication vectors from UDM

Question 5

NWDAF

Answer 5

Network Data Analytics Function

Provides slice specific network data analytics to other NFs

Question 6

NRF

Answer 6

Network Repository Function
Service registration from network functions
Network function service discovery
Used by all network functions

Question 7

AMF

Answer 7

Access and Mobility Management Function
UE registration and connection management
Stores policy data for PCF and Application data for the NEF
Transport of NAS SM messages between UE and SMF

Question 8

UDM

Answer 8

Unified Data Management

Retrieves subscription profile from the UDR

Question 9

UDR

Answer 9

User Data Repository
Repository for subscriber profile data
Stores policy and application-specific data

Question 10

UDSF

Answer 10

Unstructured Data Storage Function

Can be used by any other Network Function to store data

Question 11

SMF

Answer 11

Session Management Function 
Manages user PDU sessions 
Retrieves policy information from the PCF
UE IP address assignment
Selects UPF for PDU sessions

Question 12

PCF

Answer 12

Policy Control Function
Provides policies, charging rules, flow control rules, and Quality of Service rules to the SMF for PDU sessions
Accepts requests for new QoS flows from external entities
Retrieves subscription policy data from UDR

Question 13

NEF

Answer 13

Network Exposure Function
Permits external application secure access to some capabilities of the 5G network
UE event notification
Security exposes the services and capabilities of the PCF

Question 14

CHF

Answer 14

Charging Function
Session and event based offline charging services
Provides notifications for spending limit controls

Question 15

UPF

Answer 15

User Plane Function
Transports user traffic between the gNB/N3IWF and data networks
Enforces QoS within the network
Anchor point for Intra-/Inter-RAT mobility

Question 16

AF

Answer 16

Application Function
Interacts with NEF for untrusted access and PCF for trusted access
Influences traffic routing