Cisco Unified Communications Manager only: The Cisco Certificate Trust List (CTL) Provider service, which runs with local system account privileges, works with the Cisco CTL Provider Utility, a client-side plug-in, to change the security mode for the cluster from nonsecure to mixed mode. When you install the plug-in, the Cisco CTL Provider service retrieves a list of all Cisco Unified Communications Manager and Cisco TFTP servers in the cluster for the CTL file, which contains a list of security tokens and servers in the cluster.
You can install and configure the Cisco CTL Client or the CLI command set utils ctl, and then activate this service for the clusterwide security mode to change from nonsecure to secure.
After you activate the service, the Cisco CTL Provider service reverts to the default CTL port, which is 2444. If you want to change the port, see the Cisco Unified Communications Manager Security Guide for more information.