3GPP 23.501 v20.2.0 — the document's own text
5.3.3.1 General
Taught in 9. Registration, reachability and paging (The 5G system architecture, in depth), 4. Knowing who you are and where you are (The 5G system architecture, overview).
Connection management comprises the functions of establishing and releasing a NAS signalling connection between a UE and the AMF over N1. This NAS signalling connection is used to enable NAS signalling exchange between the UE and the core network. It comprises both the AN signalling connection between the UE and the AN (RRC Connection over 3GPP access or UE-N3IWF connection over untrusted N3GPP access or UE-TNGF connection over trusted N3GPP access) and the N2 connection for this UE between the AN and the AMF.