Computer telephony integration and its applications

Computer telephony integration (CTI) enhances the capability and flexibility of the switches or the network end equipment by computer technology. This article introduces the components of CTI such as switch-to-host interfaces, application programming interfaces, and resource architectures. Then we describe two CTI configurations: first-party call control and third-party call control. CTI-based telecommunication services such as unified messaging and call center are described. We also illustrate the Integrated Office Telephony System (IOTS), a CTI system developed at Computer Communication Research Laboratories, which integrates the switch and CTI server on a personal computer platform.