Communication Manager uses TLS to encrypt the signaling channel between Communication Manager and 96x1-H.323 deskphones. After the exchange of Gatekeeper Request (GRQ) and Gatekeeper Confirm (GCF) messages is complete, the 96x1-H.323 deskphone opens a TCP/TLS channel towards Communication Manager and communication between the endpoint and Communication Manager happens through the encrypted TLS channel.

In releases before Communication Manager Release 7.0.1, you must enable FIPS mode to use TLS. With Communication Manager Release 7.0.1 or later, you can use TLS with or without enabling the FIPS mode.