Question: In GTPv1-U, how are the IP Source and Destination Addresses determined for a Supported Extension Headers Notification message?
Option 1: IP Source: Copied from IP source of triggering GTP message; IP Destination: Copied from IP destination of triggering GTP message
Option 2: IP Source: Copied from IP destination of triggering GTP message; IP Destination: Copied from IP source of triggering GTP message
Option 3: IP Source and Destination: Both copied from IP source of triggering GTP message
Option 4: IP Source and Destination: Both copied from IP destination of triggering GTP message
Explanation: This is correct because, for a Supported Extension Headers Notification message in GTPv1-U, the IP Source Address is derived from the IP destination address of the triggering GTP message (to ensure the response reaches the originator), and the IP Destination Address is derived from the IP source address of the triggering GTP message (the original sender's address). This swap ensures proper routing back to the initiator of the interaction.