An introduction to TSAPI and network telephony

Discusses the integration of the telephone into the desktop work environment. This objective can be achieved in a number of different ways. The approach described uses the client-server model. Network telephony is a service that provides the capability to establish, answer, route, and terminate telephone calls under the control of applications on either desktop computers or servers resident in the network. It is accessed by applications via a standard programming interface (telephony services application programming interface, TSAPI) and utilizes a centralized server-based interface with the private branch exchange (PBX) to access the switching and telephone control services that the PBX provides. Creating a logical control link between the application software on the desktop computer and the telephone on the desk eliminates the need to physically connect the telephone to the desktop computer. The author distinguishes between the application programming interface and the network telephony service provider. The author assumes the services are provided by NTS R2.2 release and a PBX-based switching service. However, the author uses the term PBX to include switching services provided by key telephone or hybrid systems, PC-based telephony cards, or other appropriate technologies.