TAPI

Overview

Microsoft uses TAPI (Telephone API) for placing calls from Outlook (or dialer.exe)

To take advantage of dialing from Outlook with an SIP phone you need a SIP TAPI driver.

I've tested out a few, and SIPTAPI from IPCom does the job. http://www.ipcom.at/en/telephony/siptapi/

Install

You install by copying siptapi.tsp to the %systemroot%\system32 directory.

Configuration

Then launch the Phone and Modem Options from Control Panel (assuming Win XP).

Click the 'Advanced' Tab then click 'Add'

Select SIPTAPI Service Provider and click 'Add'

Then select SIPTAPI Service Provider and click 'Configure'

The settings are fairly self explanatory.
I did find that with my CudaTel device (based on FreeSwitch) that I it would not work if the User: and User's Extension: fields were the same. So I created extension 499 so the SIPTAPI device could authenticate, but set the User's extension to my own extension 200. It seems that my CudaTel doesn't like for forward a call to itself. In my case this actually worked better, having a single extension for TAPI makes it easy to deploy as I only have to remember 1 password (as opposed to a different password for each extension). I actually just exported the SIPTAPI values from the registry, and this can be pushed along with the siptapi.tsp file via Group Policy. So the only configuration actually needed is the User's Extension:.

Outlook 2007 & 2010

If you want to use SIPTAPI with Outlook versions 2007 and above you need to make a few changes to the registry (Editing the registry directly is dangerous, DO THIS AT YOUR OWN RISK) Outlok 2007 and up are setup to use Ofice Communicator by default so we need to override that setting with TAPI.

run regedit.exe

Navigate to: HKLM\SOFTWARE\Microsoft\Office\Outlook

Create a new 'Key' named

Call Integration

Then create a new DWORD Value named:

TAPIOVERRIDE

with a decimal value of 1

Restart Outlook and you should be able to place a call from your contacts. Just right click the contact and click call. Then you will see this screen: