Question: What should a UE that is only capable of IPv6 do when setting the PDU session type IE in the PDU SESSION ESTABLISHMENT REQUEST message?
Option 1: Set the PDU session type IE to IPv4.
Option 2: Set the PDU session type IE to IPv6.
Option 3: Set the PDU session type IE to IPv4v6.
Option 4: Not set the PDU session type IE.
Explanation: According to the specifications, a UE that is only capable of IPv6 should set the PDU session type IE to IPv6. This ensures that the network allocates an IP address based on the UE's capabilities and configuration.