The Free On-line Dictionary of Computing (30 December 2018):

Computer Telephone Integration
Computer Telephony
Computer Telephony Integration
CT

    (CTI or "- Telephony -") Enabling computers to
   know about and control telephony functions such as making and
   receiving voice, fax and data calls, telephone directory
   services and caller identification.

   CTI is used in call centres to link incoming calls to computer
   software functions such as database look-up of the caller's
   number, supported by services such as Automatic Number
   Identification and Dialled Number Identification Service.

   Application software (middleware) can link personal computers
   and servers with telephones and/or a PBX.  Telephony and
   software vendors such as AT&T, British Telecom, IBM,
   Novell, Microsoft and Intel have developed CTI services.

   The main CTI functions are integrating messaging with
   databases, word processors etc.; controlling voice, fax,
   and e-mail messaging systems from a single application
   program; graphical call control - using a graphical user
   interface to perform functions such as making and receiving
   calls, forwarding and conferencing; call and data
   association - provision of information about the caller from
   databases or other applications automatically before the call
   is answered or transferred; speech synthesis and speech
   recognition; automatic logging of call related information
   for invoicing purposes or callback.

   CTI can improve customer service, increase productivity, reduce
   costs and enhance workflow automation.

   IBM were one of the first with workable CTI, now sold as
   "CallPath".  Callware's Phonetastic is another middleware
   product.

   CTI came out of the 1980s call centre boom, where it linked
   central servers and IVRs with PBXes to provide call
   transfer and screen popping.  In the 1990s, efforts were
   made by several vendors, such as IBM, Novell TSAPI and
   Microsoft TAPI, to provide a version for desktop computers
   that would allow control of a desktop telephone and assist in
   hot desking.

   See also Telephony Application Programming Interface.

   (2012-11-18)