Question: In a 5G System (5GS) supporting IPTV service via PDU Sessions, what does the 'IP Multicast Accept' Action value in a Forwarding Action Rule (FAR) imply for the User Plane Function (UPF) upon receiving an IGMPv3 Leave message or MLD Done message?
Option 1: The UPF should ignore the message and maintain the existing multicast group distribution.
Option 2: The UPF should accept new multicast join requests from other PDU Sessions.
Option 3: The UPF should initiate a new multicast stream to the PDU Session.
Option 4: The UPF needs to ensure the PDU Session is removed from the requested multicast group distribution.
Explanation: This is correct because, in supporting IPTV services, 'IP Multicast Accept' implies that upon detecting leave messages (IGMPv3 Leave or MLD Done), the UPF must ensure the PDU Session is removed from the multicast distribution, crucial for efficient resource management and accurate multicast group updates.