Installing TAPI Service Providers (131356)

MORE INFORMATION

First and foremost, be sure to do version checking when installing all files.

Second, use a setup application rather than relying on an .INF file. While the ATSP sample uses a .INF file to install, there are several major problems with using a .INF file:

• TAPI needs to already be installed (which isn't guaranteed under Windows 3.1 or Windows for Workgroups).
• You can't do operating system version checking if you use an .INF file.
• You can't do file version checking with an .INF file.
• Bugs that won't be fixed in Windows NT 4.0 prevent an .INF file installation.

Files Necessary for Windows 3.1 or Windows for Workgroups

When a TSP is installed under Windows 3.1 or Windows for Workgroups, it must check and make sure all the necessary system files are present. The files to be installed can be found in the TAPI 1.0 SDK \REDIST directory and must be distributed with the TSP. Some of these are optional and some are not. Here is a list of files and where they should be placed:

Mandatory TAPI files: Optional TAPI files:

Files Necessary for Windows 95 and Windows NT 4.0

The TAPI 1.0 redistributable files are only for use on Windows 3.1 and Windows for Workgroups. These files must not be installed to any other operating systems. Other Windows operating systems either don't support TAPI (Windows NT 3.51 and earlier) or come with TAPI already installed (Windows 95, Windows NT 4.0 and later versions of both platforms).

One complication for Windows 95 is the TELEPHON.CPL file. This file is installed to the system directory by default along with all the rest of the Windows 95 TAPI files. However, because this file is not needed by most people using Windows 95, it is installed in the system directory as TELEPHON.CP$ to reduce control panel clutter. TSPs that need this applet should first look in the system directory for TELEPHON.CPL; if that isn't found, the TSP should locate TELEPHON.CP$ (also looking in the system directory), and rename it to TELEPHON.CPL.

Installing the TSP

Once all the files are installed, the TSP must now be installed into TAPI. Under Windows version 3.1, this is done through the Telephony Control Panel applet (TELEPHON.CPL). There are no APIs to automate the installation, so TSP installation programs must either tell the user how to install their TSP into TAPI or use an application such as MSTEST that can simulate keystrokes to automate this part of the installation. Note that TSPs must have version information (as demonstrated by the ATSP sample) to show in the Add Driver dialog.

Adding TSPs through the Telephony Control Panel is also available under Windows 95 and Windows NT 4.0, but the exact sequence of keystrokes is slightly different. However, several TAPI APIs (lineAddProvider, lineConfigProvider, and lineRemoveProvider) have been added that make the TELEPHON.CPL installation unnecessary. It's a good idea for TSP to have its own control panel applet that calls these APIs, rather than rely on TELEPHON.CPL. The setup program should install the TSP directly by using these APIs instead of asking the user to run a control panel applet.