3GPP 23.501 v20.2.0 — the document's own text
6.2.9A TNGF
Taught in 4. What each network function does (The 5G system architecture, in depth), 2. Who does what in the core (The 5G system architecture, overview).
The functionality of TNGF in the case of trusted non-3GPP access includes the following:
- Terminates the N2 and N3 interfaces.
- Terminates the EAP-5G signalling and behaves as authenticator when the UE attempts to register to 5GC via the TNAN.
- Implements the AMF selection procedure.
- Transparently relays NAS messages between the UE and the AMF, via NWt.
- Handles N2 signalling with SMF (relayed by AMF) for supporting PDU sessions and QoS.
- Transparently relays PDU data units between the UE and UPF(s).
- Implements a local mobility anchor within the TNAN.
- Packet marking in the downlink and the uplink on N2 and N3, as for the N3IWF (clause 6.2.9).
- ECN marking for L4S, as for N3IWF (clause 6.2.9).
- Optionally, supporting PDU Set based Handling as defined in clause 5.37.5.