Establishing a Link

Before an application can call the functions of Win32 Telephony for using a line device, it must take the following steps:

• Initialize the TAPI environment and TAPI's functions with an initialization function. Invoking this function also informs the application of the number of line devices available.
• Negotiate the API version, and if necessary, negotiate the Extensions version.

An application must take the preceding steps for each line device it intends to use.

Applications should not invoke phoneInitializeEx without subsequently opening a phone (at least for monitoring). If the application is not monitoring and not using any devices, it should call phoneShutdown so that memory resources allocated by the TAPI dynamic-link library can be released if unneeded, and the library itself can be unloaded from memory while not needed.