A collaboration engineer is enabling desk phone control for an existing group of Cisco Jabber desktop users. The users have been granted the appropriate permissions in Cisco UCM, and the devices are c

Cisco XCP Authentication Service handles XMPP login authentication for IM and Presence and is unrelated to CTI-based desk phone control.

Cisco CTIManager is the UCM service that implements the TAPI/JTAPI CTI interface. When Jabber uses desk phone control mode, it establishes a CTI connection through CTIManager to send call control commands (answer, hold, transfer) to the associated physical device. Without CTIManager running, no CTI application including Jabber can control desk phones regardless of user permissions or device configuration.

Cisco XCP Connection Manager manages XMPP client connections for instant messaging, not CTI desk phone control sessions.

Cisco Extended Functions handles features like QRT and call recording but is not required for basic CTI desk phone control in Jabber.