Question: In a Generic Authentication Architecture (GAA) setup, what happens to an application-specific User Security Setting (USS) in the Home Subscriber Server (HSS) if a service is temporarily revoked from a subscriber?
Option 1: The HSS permanently deletes the application-specific USS from the Generic User Security Settings (GUSS).
Option 2: The HSS may temporarily remove the application-specific USS from the GUSS, with updates to the Bootstrapping Server Function (BSF) occurring upon session timeout or a new bootstrapping session.
Option 3: The BSF immediately updates its local copy of the GUSS by removing the revoked application's USS without waiting for a new bootstrapping session.
Option 4: No action is taken in the HSS regarding the GUSS, but the NAF (Network Application Function) is notified to deny service temporarily.
Explanation: This option correctly reflects the behavior described for temporary revocation of a service from a subscriber. The HSS has the capability to temporarily remove an application-specific USS from the GUSS, but this change in the HSS does not immediately affect the BSF's copy of the GUSS. Instead, the BSF's version of the GUSS is updated either when the existing bootstrapping session times out or when a new bootstrapping session is initiated, at which point the modified GUSS (without the temporarily revoked USS) is fetched from the HSS.