Telephony Service Providers


A telephony service provider (TSP) is a dynamic-link library (DLL) that supports communications device control through a set of exported service functions. A TAPI application uses standardized commands, TAPI passes information to the telephony service provider, and the TSP handles the specific commands that must be exchanged with the device.

A TSP must conform to the Telephony Service Provider Interface (TSPI) to function as a service provider within the Microsoft Telephony environment. TSPI defines the external functions exposed by a telephony service provider supplied with communications equipment.

Developer audience

You can write TAPI-enabled applications in many languages, including Java, Visual Basic, and C/C++. Previous development experience with telecommunications or other telephony applications is helpful but not necessary.

Run-time requirements

TSPI enables development of TSPs for all versions of Windows.

In this section



General information about TSPI's architecture and components.


Documentation for the TSPI interfaces.


Related topics

Microsoft Telephony Overview
Media Service Providers
TAPI 2.2
TAPI 3.1