TAPI (Telephone Application Programming Interface) is part of Microsoft Windows. It gives software applications access to telephony hardware, independent of the hardware it is accessing. This allow applications such as Outlook to be able to dial the phone, or CRM applications to screen pop on inbound calls with relevant details (without the software knowing what the hardware is).


babblevoice TAPI is a SIP TAPI driver. It bridges the gap between Internet telephone calls and the application on your computer. So know you can click to dial from Act, Outlook or screen pop from Outlook (third party software required).

What’s more, we have open sourced this driver (which is our second driver asttapi being the first). So it is free to use on your babblevoice account and it is free to use on your own SIP implementation.


It is very simple to install. We have tested it on Windows XP and should work on any platform since although there is no 64 bit version. Simply:

  • Install the driver from sourceforge
  • In Windows Control Panel, go to Phone and Modem options, advanced, configure then
  • The registration information is the SIP account you want to register the TAPI driver against. Think of it as simply another phone. In babblevoice this is its own device.
  • The URI takes the form of, enter the password
  • The lines then can be added which you can have multiple of, a line has
  • Name - simply a text description you want to recognise it as - it could be the same as URI
  • URI - the phone account of the phone you want to act on behalf of, or the phone you want to make calls from using the TAPI driver, or seen screen pops when that phone rings.
  • Debug file is for if you are having problems with it, enter a location and file name to generate a file with this information.
  • Now, once this is all configured, open your application you intend to use and away you go.

Some Applications

  • Outlook supports click to dial
  • Windows dialer can dial for you
  • Sage Act can click to dial, we believe there are some 3rd party add-ons for screen popping
  • Identapop pro, from Identafone, good for screen popping Outlook contact information and integrating with 3rd party web CRM applications


It is primarily designed to work with babblevoice, however it has been tested and works with Freeswitch, the open source telephony switch.

Theoretically it should work with any SIP server which supports RFC 4235. We have tested it with Asterisk, but unfortunately hardly works. This is because we use a type of SIP presence unsupported by Asterisk - RFC 4235.

In the mean time there is still asttapi available at sourceforge.

Thank you

SIP Sofia is a large component in bv-tapi which is an open source SIP library which has come out of the Labs at Nokia.