Question: Upon termination of an interconnect agreement between two operators in a telecom network, what action MUST each concerned operator take regarding the certificates of the terminated operator's Interconnection CA, TLS client CA, and TLS server CA?
Option 1: Immediately revoke all associated certificates but do not update their local revocation lists.
Option 2: List the cross-certificate in their own local Certificate Revocation List (CRL) or Online Certificate Status Protocol (OCSP) server.
Option 3: Permanently store the certificates for future reference but do not utilize them.
Option 4: Automatically transfer the certificates to a shared industry repository.
Explanation: When an interconnect agreement is terminated, to maintain network security and prevent potential misuse of the terminated operator's certificates, each concerned operator must ensure these certificates are marked as invalid. Listing the cross-certificates in their local CRL or OCSP server effectively notifies all network components to reject connections based on these certificates, thus preventing unauthorized access. This action aligns with best practices for securing telecom networks post-interconnection termination.