Question: Upon User Authentication Failure in an IP-based service, as per 3GPP security standards, what action is taken by both the User Equipment (UE) and the Proxy-Call Session Control Function (P-CSCF) regarding their Transport Layer Security (TLS) connection?
Option 1: Only the UE initiates closure of the TLS connection.
Option 2: Both the UE and the P-CSCF close the TLS connection and delete the associated TLS session if established.
Option 3: The P-CSCF alone closes the TLS connection without deleting the TLS session.
Option 4: No action is taken on the existing TLS connection by either party.
Explanation: In the event of user authentication failure, to maintain security integrity and prevent potential unauthorized access, both the UE (User Equipment) and the P-CSCF (Proxy-Call Session Control Function) are required to close the Transport Layer Security (TLS) connection. Additionally, if a TLS session was established as part of this connection, it must also be deleted by both parties to fully sever the secure link and necessitate re-authentication for any future connections, thus ensuring the security of IP-based services in accordance with 3GPP standards.