Question: What happens at the P-CSCF if the authentication and encryption algorithms list received in Security Mode (SM) message 7 does not match the list sent in SM message 6 during a registration procedure?
Option 1: The P-CSCF sends a warning alert to the User Equipment (UE) but continues with the registration.
Option 2: The P-CSCF aborts the registration procedure.
Option 3: The P-CSCF attempts to negotiate an alternative set of algorithms with the UE.
Option 4: The P-CSCF ignores the mismatch and proceeds with the default security settings.
Explanation: This is because, according to the specified security protocol for IP-based services in telecom networks, a mismatch in the security setup between what is expected (sent in SM6) and what is received (in SM7) indicates a potential security risk. Aborting the registration procedure ensures the integrity of the network's security by not allowing potentially compromised or incorrectly configured sessions to establish. This aligns with standard practices for maintaining secure connections in telecommunications, prioritizing security over the convenience of a successful connection at all costs.