Question: In Un-trusted Non-3GPP IP access via S2c, where is Lawful Interception (LI) performed in the Visited Public Land Mobile Network (VPLMN) for I-WLAN, according to 3GPP security standards?
Option 1: ePDG (Evolved Packet Data Gateway)
Option 2: PDN-GW (Packet Data Network Gateway)
Option 3: UE (User Equipment)
Option 4: DS-MIPv6 Server
Explanation: In the context of Un-trusted Non-3GPP IP access for I-WLAN, Lawful Interception in the VPLMN is specifically required to be performed at the ePDG. This is because the ePDG acts as a security gateway between untrusted non-3GPP networks (like I-WLAN) and the trusted 3GPP Evolved Packet Core (EPC), making it a critical point for intercepting communications as per lawful interception requirements for PDG (Packet Data Gateway) functions.