of the connections is named - this name comprises the letter "N," followed by a number to uniquely identify the connection between the two NFs. We will go into the details of what role each of these NFs performs and how it interoperates with its neighboring NFs: 5G network concepts VPLMN HPLMN 23.501, 23.502, 23.503: 5GC Stage 2 29.500, 29.501: SBA 33.126/127/128: Lawful Intercept Stage 1/2/3 29.571 : Data Types 29.573 33.501: : Security 32.255 29.531 29.504 32.290 Charging Flows 29.522 29.505 29.519 29.503 Subscpt Strcture App Data Policy Converged Spending Charging Limit 29.531 29.509 29.504 32,291 29.594 29.551 29.510 29.504 29.520 29.503 -29.518] 29.502 29.554 29.523 29.540 29.518 29.508 Events 29.518 Policy Policy 29.511 29.512 29.514 29.502 Policy 29.507 29.525 29.521 24.501 NAS 29.524 24.526 UE Policies NAS Error HTTP Error 29.244 29.513 Policy Flows 38.413 29.413 NG-PAM 29.281 29.561 38.415 Control 38.300: NG-RAN Stage 2 29.281 Non-3GPP N31WT 24.502 Figure 2.3 - 5G packet core reference points This diagram details the various constituents of a 5G network. In the previous sections, we have focused mainly on radio and transport. In the upcoming sections, we will cover each NF. The AMF A reference point diagram for an AMF is shown in Figure 2.4. The AMF is connected to various other NFs via well-defined interfaces, as indicated here: NG-RAN N3-IWF Figure 2.4 - AMF reference points End-to-End Architecture Components, Concepts, Security, and Transport It must be noted that all these interfaces are service-based interfaces. We will learn more about the service-based model in the next chapter. The numbers denote a specific connection name: N11: This is the interface that connects the AMF to the SMF, and the AMF controls it N15: This is the interface that connects the AMF to the PCF N2: This is the interface that connects the AMF to the N3-Interworking Function (N3-IWF) and the Next Generation Radio Access Network (NG-RAN) N1: This is the virtual interface that connects the AMF to the UE for signaling N17: This i