computer supported telecommunications application (CTI) (CSTA)

Computer Supported Telecommunications Application (CSTA) is a standard of the European Computer Manufacturers Association( ECMA) for computer supported Tk applications for the coupling of computer and telephone in computer telephony integration( CTI).

The CSTA standard specifies the structure and type of messages for the various service features, such as toggling, call forwarding, three-party conferencing, and so on.

CSTA is not a specified interface, but rather a guideline for the standardized implementation of CTI functionality. CSTA is accepted and implemented by almost all PBX manufacturers. Examples of standard-compliant implementation are the Telephony Service Application Programming Interface( TSAPI) and Telephony Application Programming Interface( TAPI) programming interfaces, which are based on the CSTA definitions.