Cisco CTL Client 5.0

Cisco CTL Client by Cisco Systems, Inc. is a Windows-based administrative utility for Cisco Unified Communications Manager (CUCM) environments. It creates, signs, and maintains the cluster’s Certificate Trust List (CTL), which Cisco IP phones use to verify trusted services and to download signed configuration files. Using hardware security tokens, the CTL Client authenticates and signs entries for core services such as Cisco CallManager, Cisco TFTP, and the Certificate Authority Proxy Function (CAPF), then distributes the resulting CTL file across the cluster. Administrators typically use the tool when enabling or maintaining mixed-mode security, adding or removing nodes, or updating certificates. By centralizing CTL management, Cisco CTL Client helps enforce device authentication and supports secure, encrypted communications across Cisco Unified Communications deployments.

Key capabilities:

• Generate and update the CTL file for CUCM clusters
• Hardware token–based signing and validation
• Automatic retrieval and inclusion of service certificates
• Cluster-wide CTL distribution via TFTP
• Support for mixed-mode security enablement and ongoing maintenance

Cisco CTL Client is developed by Cisco Systems Inc.. The most popular version of this product among our users is 5.0. The name of the program executable file is CTLClient.exe.