Question: What is the restriction on PDU session types that can be transferred to an ePDG connected to EPC?
Option 1: Only PDU sessions with PDU session type "IP" can be transferred.
Option 2: All PDU session types, including "Ethernet", "Unstructured", and "IP", can be transferred.
Option 3: The UE can choose which PDU session types to transfer based on the interworking without N26 interface indicator.
Option 4: PDU sessions with PDU session type "Ethernet" or "Unstructured" cannot be transferred.
Explanation: This is because PDN connections with PDN type "non-IP" or PDN type "Ethernet" are not supported over ePDG connected to EPC, making it impossible for the UE to transfer PDU sessions with these types.