Computer telephony integration, also called computer–telephone integration or CTI, is a common name for any technology that allows interactions on a
telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...
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
A desktop traditionally refers to:
* The surface of a desk (often to distinguish office appliances that fit on a desk, such as photocopiers and printers, from larger equipment covering its own area on the floor)
Desktop may refer to various compu ...
-based interaction for helping users be more efficient, though it can also refer to server-based functionality such as automatic
call
Call or Calls may refer to:
Arts, entertainment, and media Games
* Call, a type of betting in poker
* Call, in the game of contract bridge, a bid, pass, double, or redouble in the bidding stage
Music and dance
* Call (band), from Lahore, Paki ...
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
Ani ( hy, Անի; grc-gre, Ἄνιον, ''Ánion''; la, Abnicum; tr, Ani) is a ruined medieval Armenian city now situated in Turkey's province of Kars, next to the closed border with Armenia.
Between 961 and 1045, it was the capital of the ...
), number dialed (
DNIS 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 t ...
), and
Screen pop
Screen pop is a call centre term that refers to the feature of a computer telephony integration (CTI) which automatically displays customer information via a window or dialog box on an agent's computer upon answering a customer's call.
For ''inb ...
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
Screen pop is a call centre term that refers to the feature of a computer telephony integration (CTI) which automatically displays customer information via a window or dialog box on an agent's computer upon answering a customer's call.
For ''inb ...
with the call.).
*
Call center - 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
A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulati ...
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
Screen pop is a call centre term that refers to the feature of a computer telephony integration (CTI) which automatically displays customer information via a window or dialog box on an agent's computer upon answering a customer's call.
For ''inb ...
") 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,
TSAPI and
TAPI: JTAPI, the Java Telephony API is promoted by Sun; TSAPI, originally promoted by the AT&T (later Lucent then
Avaya
Avaya Holdings Corp., often shortened to Avaya (), is an American multinational technology company headquartered in Durham, North Carolina, that provides cloud communications and workstream collaboration services. The company's platform inclu ...
) 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
Lucent Technologies, Inc. was an American multinational telecommunications equipment company headquartered in Murray Hill, New Jersey. It was established on September 30, 1996, through the divestiture of the former AT&T Technologies business u ...
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
Middleware is a type of computer software that provides services to software applications beyond those available from the operating system. It can be described as "software glue".
Middleware makes it easier for software developers to implement co ...
. This attempt failed when it sold this company to
Siemens AG
Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad.
The principal divisions of the corporation are ''Industry'', ''E ...
and gradually divested in the area. A pioneer startup that combined the technologies of voice digitization, Token Ring networking, and
time-division multiplexing was ZTEL of
Wilmington, Massachusetts
Wilmington is a town in Middlesex County, Massachusetts, United States. Its population was 23,349 at the 2020 United States census.
History
Wilmington was first settled in 1665 and was officially incorporated in 1730, from parts of Woburn, Readi ...
. 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
Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president unt ...
and Tiger Software (now Mondago). Digital Equipment Corporation developed
CT Connect 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 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 sigh ...
. The CSTA advocates were: Siemens (now Unify),
Aastra
Aastra Technologies Limited, formerly headquartered in Concord, Ontario, Canada, made products and systems for accessing communication networks, including the Internet. Its products included residential and business telephone terminals, screen ...
,
DeTeWe,
Toshiba
, commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure system ...
,
Panasonic
formerly between 1935 and 2008 and the first incarnation of between 2008 and 2022, is a major Japanese multinational conglomerate corporation, headquartered in Kadoma, Osaka. It was founded by Kōnosuke Matsushita in 1918 as a lightbulb ...
. The majority (see main
TAPI article for detail) preferred TAPI. A few vendors promoted proprietary standards:
Mitel
Mitel Networks Corporation is a Canadian telecommunications company. The company previously produced TDM PBX systems and applications, but after a change in ownership in 2001, now focuses almost entirely on Voice-over-IP (VoIP) products. Mitel ...
,
Broadsoft
BroadSoft, Inc. is a communication software and service provider that was acquired by Cisco Systems in 2018. BroadSoft was founded in 1998 and completed its initial public offering in 2010, and was headquartered in Maryland. It partners with carri ...
,
Digium
Digium, Inc. is a communications technology company based in Huntsville, Alabama, and since 2018, a subsidiary of Sangoma Technologies Corporation. The company makes VoIP business phone systems, IP phones, and hardware products. It was founded ...
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
Acton is a town in Middlesex County, Massachusetts, United States, approximately west-northwest of Boston along Massachusetts Route 2 west of Concord and about southwest of Lowell. The population was 24,021 in April 2020, according to the Unit ...
firm that developed a
CORBA
The Common Object Request Broker Architecture (CORBA) is a standard defined by the Object Management Group (OMG) designed to facilitate the communication of systems that are deployed on diverse platforms. CORBA enables collaboration between s ...
based CTI solution for a client and then decided to make it into a general product. It merged with Quintus, a
customer relationship management
Customer relationship management (CRM) is a process in which a business or other organization administers its interactions with customers, typically using data analysis to study big data, large amounts of information.
CRM systems data collectio ...
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" 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
The Internet Engineering Task Force (IETF) is a standards organization for the Internet and is responsible for the technical standards that make up the Internet protocol suite (TCP/IP). It has no formal membership roster or requirements and a ...
, 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
Snom Technology GmbH is a German company which manufactures Voice over Internet Protocol (VoIP) telephones, based on the IETF standard Session Initiation Protocol (SIP). Snom's products are targeted at the small- to medium-sized business secto ...
(the first to pioneer it),
Yealink,
Akuvox, Panasonic and Aastra.
See also
*
Automatic number identification
Automatic number identification (ANI) is a feature of a telecommunications network for automatically determining the origination telephone number on toll calls for billing purposes. Automatic number identification was originally created by the A ...
(ANI)
*
Automatic call distributor
An automated call distribution system, commonly known as automatic call distributor (ACD), is a telephony device that answers and distributes incoming calls to a specific group of terminals or agents within an organization. ACDs direct calls based ...
*
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
*
Predictive dialer
A predictive dialer dials a list of telephone numbers and connects answered dials to people making calls, often referred to as agents. Predictive dialers use statistical algorithms to minimize the time that agents spend waiting between conversation ...
*
Screen pop
Screen pop is a call centre term that refers to the feature of a computer telephony integration (CTI) which automatically displays customer information via a window or dialog box on an agent's computer upon answering a customer's call.
For ''inb ...
*
Telephony Application Programming Interface
The Telephony Application Programming Interface (TAPI) is a Microsoft Windows API, which provides computer telephony integration and enables PCs running Microsoft Windows to use telephone services. Different versions of TAPI are available on diff ...
(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 ra ...
(CSTA)
*
Multi-Vendor Integration Protocol
External links
*
User Agent CSTA (uaCSTA) - TR/87 - ECMA International
{{Telecommunications
Telephone service enhanced features