Question: In a UE-initiated IP-CAN Session termination scenario, what triggers the procedure at the GGSN if it's not the last PDP Context for the IP Address?
Option 1: Receipt of a Delete PDP Context request with a Teardown Indicator set, indicating all shared PDP contexts should be deactivated.
Option 2: Automatic timer expiration in the GGSN for inactive PDP contexts.
Option 3: SGSN-initiated context modification request to reduce resource allocation.
Option 4: UE's IP Address renewal attempt with a different APN.
Explanation: According to telecom standards, the GGSN is triggered to terminate all associated PDP contexts not just by being the last one for an IP Address, but also if a received Delete PDP Context request includes a Teardown Indicator, signaling deactivation of all PDP contexts sharing the same IP address for resource cleanup and session closure.