TAPI (Telephony Application Program Interface) is a standard program interface that lets you and your computer "talk" over telephones or video phones to people or phone-connected resources elsewhere in the world. Assuming your computer is equipped with TAPI and your setup includes the right application and hardware, you may be able:
- Call someone by clicking on their picture or other image
- Use a similar graphical user interface (GUI) to set up a conference call and then attend the call at the scheduled time
- See who you're talking to individually or at a conference call
- Add a voice note to an e-mail note you send or listen to a voice note attached to an e-mail note you receive
- Program your computer to automatically receive phone calls from certain numbers (but not from others)
- Send and receive faxes
- Do these things from a portable wireless cellular telephone telephone/computer as well as from a desktop computer
Developed jointly by Intel and Microsoft, TAPI is included with the Windows 95/98 and Windows NT operating system. Using TAPI, programmers can take advantage of different telephone systems, including ordinary public switched telephone network, digital ISDN, and private branch exchange without having to understand all their details. Each phone system hardware provider (for example, the modem maker or ISDN card maker) provides a specific software driver that interfaces directly with the hardware.
TAPI provides a high-level interface for dialing and disconnecting. Instead of having to encode an ATDT dial string and the ATH disconnect string, the programmer codes a much simpler "function call."
In addition to the interface for applications, TAPI includes a Service Provider Interface (SPI) for hardware vendors who are writing the driver software. The TAPI Dynamic Link Library (DLL) maps the API to the SPI and coordinates input/output traffic.