Question: In a PCRF-initiated IP-CAN Session modification, what is a possible outcome when a PDP Context in the session requires changes to its Quality of Service (QoS) settings?
Option 1: The GGSN will automatically deactivate all existing PDP contexts and initiate new ones with updated QoS.
Option 2: The SGSN will directly modify the UE's (User Equipment) settings without involving the GGSN.
Option 3: The PCRF will bypass the GGSN and send an Update PDP Context Request directly to the SGSN.
Option 4: The GGSN sends an Update PDP Context Request message to the SGSN, which then responds with an Update PDP Context Response upon modification.
Explanation: In a PCRF-initiated IP-CAN Session modification, if a PDP Context's QoS needs to be updated, the procedure involves the GGSN initiating the change by sending an Update PDP Context Request to the SGSN. The SGSN then confirms the modification with an Update PDP Context Response, ensuring both network and UE are aligned with the new QoS settings for session integrity and performance as per Policy and Charging Control architecture.