Question: In the context of Lawful Interception (LI) over the X2 interface, what information is NOT necessarily transferred from the PDN-GW to the Delivery Function 2 (DF2) for performing its functionality?
Option 1: Target Identity
Option 2: Quality of Service (QoS) Information, if available
Option 3: Encryption Parameters (keys and associated parameters for decrypting CC), only if explicitly requested by DF2
Option 4: Complete Call Content (CC) in Plain Text
Explanation: The correct answer is Option 4 because what is transferred for decryption purposes are 'encryption parameters (keys and associated parameters for decrypting CC), if available and necessary', not the complete call content in plain text. This ensures that only the necessary information for lawful interception is provided, maintaining privacy and security protocols.