Question

A remote engineer reports that Jabber successfully logs in through MRA and can search the corporate directory, but calls fail to establish with a secure SIP profile applied. Non-secure phones registering internally work fine. Packet captures on the Expressway-C show the SIP INVITE reaching CUCM, but CUCM logs indicate a failed TLS handshake for the encrypted signaling channel. Which action most directly resolves the secure call failure?

Accepted Answer

Ensure the Expressway-C certificate is signed by a CA trusted by CUCM and that the CUCM Tomcat/CallManager trust stores include the Expressway-C CA certificate

Answer

Enable mixed mode on the CUCM cluster and issue a new CTL file so encrypted media can traverse the Expressway pair

Answer

Change the Expressway-E to Expressway-C traversal zone from TLS to TCP to avoid the certificate negotiation

Answer

Increase the SIP session timer and re-register the Jabber client to force a new secure signaling connection