Question: What is the primary function of the IMS Application Layer Gateway (ALG) in IP version interworking for IMS sessions?
Option 1: To modify SIP message bodies and headers with IP address associations, translating between IPv6 and IPv4 addresses.
Option 2: To manage UE authentication across different IP versions within the IMS network.
Option 3: To prioritize traffic from IPv6 UEs over those using IPv4 in congested networks.
Option 4: To handle all DNS queries for both IPv4 and IPv6-enabled User Equipment (UE).
Explanation: The IMS ALG plays a crucial role in facilitating communication between IPv6 and IPv4 SIP applications by modifying the necessary SIP/SDP parameters. This involves translating IP addresses (IPv6 to IPv4 and vice versa) within the SIP message bodies and headers that contain IP address associations, ensuring seamless interworking without disrupting IMS sessions.