Question: How does a User Equipment (UE) indicate its support for 'Update PDP context/bearer at P-CSCF failure' Restoration to the P-GW/GGSN during IMS PDN connection/PDP context activation?
Option 1: Through a dedicated signaling message sent directly to the P-GW/GGSN.
Option 2: By including the capability in the PCO parameter related to P-CSCF Re-selection support as part of the initial setup.
Option 3: Via periodic UE capability updates transmitted over the established PDN connection.
Option 4: Through MME/SGSN, which then informs the P-GW/GGSN about the UE's capability.
Explanation: The correct method for a UE to indicate its support is by utilizing the Protocol Configuration Options (PCO) parameter related to P-CSCF Re-selection support. This is included in the initial IMS PDN connection/PDP context setup, ensuring the P-GW/GGSN is aware of the UE's capabilities from the outset, aligning with efficient signaling use and seamless network integration.