Computer telephony integration, also called computer–telephone integration or CTI, is a common name for any technology that allows interactions on a
telephone and a
computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...
to be coordinated. The term is predominantly used to describe
desktop-based interaction for helping users be more efficient, though it can also refer to server-based functionality such as automatic
call routing
Routing is the process of selecting a path for traffic in a network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone netw ...
.
Common functions
By application type
CTI applications tend to run on either a user's desktop, or an unattended server.
;Common desktop functions provided by CTI applications
*
Screen popping - Call information display (caller's number (
ANI), number dialed (
DNIS), and
Screen pop on answer, with or without using calling line data. Generally this is used to search a business application for the caller's details.
*Dialing -
Automatic dialing and computer-controlled dialing (power dial, preview dial, and
predictive dial).
*Phone control - Includes call control (answer, hang up, hold, conference, etc.) and feature control (DND, call forwarding, etc.).
*Transfers - Coordinated phone and data transfers between two parties (i.e., pass on the
Screen pop with the call.).
*
Call center
A call centre ( Commonwealth spelling) or call center (American spelling; see spelling differences) is a managed capability that can be centralised or remote that is used for receiving or transmitting a large volume of enquiries by telephone. ...
- Allows users to log in as a call center agent and control their agent state (Ready, Busy, Not ready, Break, etc.).
;Common server functions provided by CTI applications
*Call routing - The automatic routing of calls to a new destination based on criteria normally involving a database lookup of the caller's number (ANI) or number dialed (DNIS).
*Advanced call reporting functions - Using the detailed data that comes from CTI to provide better-than-normal call reporting.
*
Voice recording
Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording te ...
integration - Using data from CTI to enrich the data stored against recorded calls.
By connection type
Computer-phone connections can be split into two categories:
;First-party call control
:Operates as if there is a direct connection between the user's computer and the phone set. Examples are a
modem or a phone plugged directly into the computer. Typically, only the computer associated with the phone can control it by sending commands directly to the phone and thus this type of connection is suitable for desktop applications only. The computer can generally control all the functions of the phone at the computer user's discretion.
;Third-party call control
:Interactions between arbitrary numbers of computers and telephones are made through and coordinated by a dedicated
telephony server
Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is i ...
. Consequently, the server governs which information and functions are available to a user. The user's computer generally connects to the telephony server over the local network.
History and main CTI technologies
The origins of CTI can be found in simple screen population (or "
screen pop") technology. This allows data collected from the telephone systems to be used as input data to query databases with customer information and populate that data instantaneously in the customer service representative screen. The net effect is the agent already has the required screen on his/her terminal before speaking with the customer.
This technology started gaining widespread adoption in markets like North America and West European countries.
There were several standards which had a major impact in the ´normalization´ of in the industry, previously fully closed and proprietary to each
PBX/
ACD vendor. On the software level, the most adopted interface by vendors is the
CSTA standard, which is approved by the standards body
ITU
The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
. Other well known CTI standards in the industry are
JTAPI The Java Telephony API (JTAPI) supports telephony call control. It is an extensible application programming interface (API) designed to scale for use in a range of domains, from first-party call control in a consumer device to third-party call contr ...
,
TSAPI
Telephony Server Application Programming Interface was a computer telephony integration standard developed and promoted by Novell and AT&T. It consisted of a number of call control commands for switching calls, voice mail and call logging using ...
and
TAPI: JTAPI, the Java Telephony API is promoted by Sun; TSAPI, originally promoted by the AT&T (later Lucent then
Avaya) and
Novell
Novell, Inc. was an American software and services company headquartered in Provo, Utah, that existed from 1980 until 2014. Its most significant product was the multi-platform network operating system known as Novell NetWare.
Under the lead ...
; Microsoft pushed their own initiative also, and thus TAPI was born, with support mostly from Windows applications. All of these standards required the
PBX vendor to write a specific driver, and initially support for this was slow.
Among the key players in this area,
Lucent played a big role and
IBM acquired
ROLM Inc, a US pioneer in ACDs, in an attempt to normalize all major PBX vendor interfaces with its CallPath
middleware. This attempt failed when it sold this company to
Siemens AG and gradually divested in the area. A pioneer startup that combined the technologies of voice digitization, Token Ring networking, and
time-division multiplexing
Time-division multiplexing (TDM) is a method of transmitting and receiving independent signals over a common signal path by means of synchronized switches at each end of the transmission line so that each signal appears on the line only a fracti ...
was ZTEL of
Wilmington, Massachusetts. ZTEL's computer-based voice and data network combined user-programmable voice call processing features, protocol conversion for automated "data call processing," database-driven directory and telset definitions, and custom LSI chipset technology. ZTEL ceased operation in 1986.
Two other important players were
Digital Equipment Corporation and Tiger Software (now Mondago). Digital Equipment Corporation developed
CT Connect CT Connect is a software product that allows computer applications to monitor and control telephone calls. This monitoring and control is called computer-telephone integration, or CTI. CT Connect implements CTI by providing server software that su ...
which includes vendor abstraction middleware. CT Connect was then sold to
Dialogic
Dialogic refers to the use of conversation or shared dialogue to explore the meaning of something. (This is as opposed to monologic which refers to one entity with all the information simply giving it to others without exploration and clarificatio ...
, which in turn was purchased by Intel. This CTI software, known as CT Connect, was most recently sold in 2005 to Envox Worldwide. Tiger Software produced the SmartServer suite which was primarily aimed at allowing CRM application vendors to add CTI functionality to their existing applications with minimal effort. Later, and after changing their name to Mondago, Tiger Software went on to produce the Go Connect server application, which is aimed at providing at helping other CTI vendors integrate with a wider range of telephone systems.
By 2008, most PBX vendors had aligned themselves behind one or two of the
TAPI, CSTA or
TSAPI
Telephony Server Application Programming Interface was a computer telephony integration standard developed and promoted by Novell and AT&T. It consisted of a number of call control commands for switching calls, voice mail and call logging using ...
standard. The TSAPI advocates were: Avaya,
Telrad
A reflector sight or reflex sight is an optical sight that allows the user to look through a partially reflecting glass element and see an illuminated projection of an aiming point or some other image superimposed on the field of view. These si ...
. The CSTA advocates were: Siemens (now Unify),
Aastra,
DeTeWe,
Toshiba,
Panasonic. The majority (see main
TAPI article for detail) preferred TAPI. A few vendors promoted proprietary standards:
Mitel,
Broadsoft,
Digium and most hosted platforms. CT Connect and Go Connect thus provided an important translation middle-layer, allowing the PBX to communicate in its preferred protocol, while an application can communicate using its preferred protocol.
Many of the early CTI vendors and developers have changed hands over the years. An example is Nabnasset, an
Acton, Massachusetts firm that developed a
CORBA based CTI solution for a client and then decided to make it into a general product. It merged with Quintus, a
customer relationship management company, which went bankrupt and was purchased by Avaya Telecommunications. Smaller organisations have also survived from the early days and have leveraged their heritage to thrive. However, many of the 1980s startups that were inspired by the "
Bell Breakup
The breakup of the Bell System was mandated on January 8, 1982, by an agreed consent decree providing that AT&T Corporation would, as had been initially proposed by AT&T, relinquish control of the Bell Operating Companies, which had provided loc ...
" and the coming competitive telephony marketplace, did not survive the decade.
On the hardware level, there was a paradigm shift since 1993, with emerging standards from
IETF, which led to several new players like
Dialogic
Dialogic refers to the use of conversation or shared dialogue to explore the meaning of something. (This is as opposed to monologic which refers to one entity with all the information simply giving it to others without exploration and clarificatio ...
, Brooktrout (now part of Dialogic), Natural MicroSystems (also now part of Dialogic) and
Aculab
Aculab is a privately held, UK-based limited company that was founded in 1978. It is a designer, developer and manufacturer that specialises in providing API-driven, enabling technology sub-systems for telecommunications related OEM products such ...
offering telephony interfacing boards for various networks and elements.
Until 2011, it was the makers of telephone systems that implemented CTI technologies such as
TAPI and CSTA. But after this time, a wave of handsets become popular that were independently made. These handsets would connect to the telephone systems using standards such as
SIP and consumers could easily buy their telephone system from one vendor and their handsets from another. However, this situation led to poor quality CTI since the protocols (ie SIP) were not really suitable for third-party control.
So, handset vendors started to add support for CTI directly. Initially this would be over proprietary HTTP methods, but in time
uaCSTA (aka TR/87) became popular and by 2016 most SIP handsets support uaCSTA control. These include:
Snom (the first to pioneer it),
Yealink,
Akuvox, Panasonic and Aastra.
See also
*
Automatic number identification (ANI)
*
Automatic call distributor
*
Dialed Number Identification Service Dialed Number Identification Service (DNIS) is a service offered by telecommunications companies to corporate clients which identifies the originally dialed telephone number of an inbound call. The client may use this information for call routing to ...
(DNIS)
*
PhoneValet Message Center
PhoneValet Message Center (or, simply, ''PhoneValet'') is a discontinued Mac-based multi-line computer-telephony software application from Parliant Corporation. The application provided computer-telephony functionality including voicemail, call ...
*
Predictive dialer
*
Screen pop
*
Telephony Application Programming Interface (TAPI)
*
Telephony Server Application Programming Interface
Telephony Server Application Programming Interface was a computer telephony integration standard developed and promoted by Novell and AT&T. It consisted of a number of call control commands for switching calls, voice mail and call logging using ...
(TSAPI)
*
Computer-supported telecommunications applications Computer-supported telecommunications applications (CSTA) is an abstraction layer for telecommunications applications. It is independent of underlying protocols. It has a telephone device model that enables CTI applications to work with a wide ran ...
(CSTA)
*
Multi-Vendor Integration Protocol
The Multi-Vendor Integration Protocol (MVIP) is a hardware bus for computer telephony integration ( Audiotex) equipment, a PCM data highway for interconnecting expansion boards inside a PC. It was invented and brought to market by Natural Micros ...
External links
*
User Agent CSTA (uaCSTA) - TR/87 - ECMA International
{{Telecommunications
Telephone service enhanced features