Question: What protocol is used for establishing the user plane between the UE and TNGF in a trusted non-3GPP access scenario?
Option 1: IKEv1 signalling
Option 2: IKEv2 signalling with Create_Child_SA exchange
Option 3: TLS handshake
Option 4: DTLS handshake
Explanation: In a trusted non-3GPP access scenario, the user plane between the UE and TNGF is established using IKEv2 signalling with a Create_Child_SA exchange. This allows for the reservation of non-3GPP specific QoS resources as defined in clause 4.12a.5.