Question: In the context of Lawful Interception (LI) for IMS supplementary services, what is the responsibility of the Application Server (AS) storing the target's XCAP data regarding XCAP-based messages?
Option 1: The AS only intercepts XCAP messages on the Ut interface for its own supplementary services.
Option 2: The AS transmits all intercepted XCAP messages to the Law Enforcement Monitoring Facility (LEMF) without encapsulation.
Option 3: The AS is responsible for filtering XCAP messages based on operator policy before transmitting them to the Delivery Function 2 (DF2).
Option 4: The AS intercepts and transmits to the DF2 any XCAP-based messages related to the target's actions on supplementary services and settings, via the Ut interface or other interfaces to XCAP server-capable AS.
Explanation: This is correct because, according to lawful interception architecture specifications, the Application Server (AS) storing the target's XCAP data must intercept and forward all relevant XCAP messages (related to supplementary services and settings modifications) to the Delivery Function 2 (DF2), regardless of whether these messages are transmitted over the Ut interface or other interfaces communicating with AS having XCAP server capabilities. This ensures comprehensive monitoring as required for lawful interception purposes. Options 1, 2, and 3 are incorrect because they either limit the scope of intercepted messages, misrepresent the transmission process to the LEMF, or incorrectly assign filtering responsibilities to the AS, respectively.