Question: In a Generic Authentication Architecture (GAA) scenario where a Network Application Function (NAF) uses User Security Settings (USSs) but the Bootstrapping Server Function (BSF) lacks a local policy for that NAF, what happens to a USS identified by a GSID if it's not found in the subscriber's Generic User Security Settings (GUSS)?
Option 1: The BSF generates a default USS for the missing GSID and includes it in the response to the NAF.
Option 2: The BSF omits this particular USS from the response sent to the NAF but includes a notification of its absence.
Option 3: The BSF derives an alternative shared key for the missing USS and sends it along with available USSs to the NAF.
Option 4: The BSF omits these USSs from the response without any further notification or action, proceeding only with available USSs.
Explanation: According to the scenario's logic, if a particular USS (identified by a GSID) is not found in the subscriber's GUSS, or if the NAF is not authorized to receive it, the BSF simply omits these USSs from its response to the NAF. There's no indication of generating defaults, sending notifications of absence, or deriving alternative keys for omitted USSs in this context. The focus is on providing only what is available and authorized, thus ensuring security and policy compliance.