• The CTIM may be activated on any of the Unified CM servers in a cluster that have the Cisco CallManager Service active. This allows up to eight CTIMs to be active within a Unified CM cluster. Standalone CTIMs are currently not supported.

• A maximum of 800 CTI connections or CTI controlled devices can be utilized per Unified CM subscriber (Cisco MCS 7825 or 7835), or a maximum of 3200 per 8-node cluster if they are equally balanced among the servers. The controlled device association limit for a single CTI application is 2000.
• A maximum of 2500 CTI connections or CTI controlled devices can be utilized per MCS 7845, or a maximum of 10,000 per 8-node cluster if they are equally balanced among the servers. The controlled device association limit for a single CTI application is 2500.
• For Cisco Unified Communications Manager Business Edition, this server has a maximum of 500 CTI devices.

<note>For JTAPI applications, a CTI connection is a single TCP/IP connection between each JTAPI application and a Unified CM server.</note> <note>For TAPI applications, a CTI connection is a single TCP/IP connection between the Cisco TSP residing on the TAPI application server and a Unified CM server. There could be multiple TAPI applications (on the same server) interfacing to a single TSP, in which case a single CTI connection would be utilized for all of those TAPI applications.</note> <note>The controlled device limits apply only to active applications; controlled devices associated to inactive (disabled) applications do not count against the limit. Assuming one CTI controlled line per device</note>