Question: Under what conditions, as per 3GPP security standards, is a Bearer deactivation event generated involving the ePDG (Evolved Packet Data Gateway) and PDN-GW (Packet Data Network Gateway)?
Option 1: Only when the UE (User Equipment) initiates a detach procedure over the LTE radio interface.
Option 2: Exclusively when the PDN-GW initiates Resource Allocation Deactivation on a non-GTP based S2b interface.
Option 3: Solely when the Detach is handled by the ePDG over a PMIP (Proxy Mobile IP) based S2b interface.
Option 4: In scenarios including: Detach handled by the ePDG over GTP S2b interface, Bearer deactivation detected at the PDN-GW, or PDN GW initiated Resource Allocation Deactivation detected by the ePDG on a GTP based S2b interface.
Explanation: This option correctly identifies all specified conditions under which a Bearer deactivation event is generated. These include: Detach handled by the ePDG over a GTP S2b interface, detection of Bearer deactivation at the PDN-GW, and detection by the ePDG of PDN GW initiated Resource Allocation Deactivation on a GTP based S2b interface.