An administrator configures a secure SIP trunk in Cisco UCM to Expressway-C. The SIP trunk fails to become active, and an examination of a packet capture finds that the TLS handshake failed with a “Certificate Unknown” error from Cisco UCM. To allow the Cisco UCM to trust the Expressway-C and establish a TLS connection, the administrator will upload the Expressway server certificate to the trust store. To which trust store must the certificate be uploaded?