Section: 4.12a.2 Registration via Trusted non-3GPP Access 4.12a.2.1 General
Content: Clause 4.12a.2 specifies how a UE can register to 5GC via a trusted non-3GPP Access Network. The utilized procedure is very similar with the 5GC registration procedure over untrusted non-3GPP access in clause 4.12.2.2 and it is based on the Registration procedure specified in clause 4.2.2.2.2. It uses the same vendor-specific EAP method (called "EAP-5G") as the one specified in clause 4.12.2.1. In this case, the "EAP-5G" method is used between the UE and the TNGF and is utilized for encapsulating NAS messages. In Registration and subsequent Registration procedures via trusted non-3GPP access, the NAS messages are always exchanged between the UE and the AMF. When possible, the UE can be authenticated by reusing the existing UE security context in AMF.