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 to be integrated or 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.
CTI applications tend to run on either a user's desktop, or an unattended server.
Computer-phone connections can be split into two categories:
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. 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) and Novell; 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.