Initializing a Fax Service Provider

Each time the fax service starts, it calls the TAPI lineInitializeEx function to retrieve the number of available line devices.

During initialization, the fax service checks the fax service provider DLL for the FaxDevVirtualDeviceCreation function. If the provider exports FaxDevVirtualDeviceCreation, an optional function, the fax service expects the fax service provider to present one or more virtual fax devices. For more information, see Virtual Fax Devices.

The fax service also calls the FaxDevInitialize function each time the service starts to initialize the communication between the service and the fax service provider DLL.

The fax service provider must register the FAX_LINECALLBACK function by supplying a function pointer when the fax service calls FaxDevInitialize. The service calls FAX_LINECALLBACK to deliver TAPI events to the fax service provider.

The fax service provider must export both FaxDevInitialize and FaxDevStartJob.

The following diagram illustrates the general flow of events during initialization of a fax service provider.

Once the fax service provider has been initialized, the provider can send and receive faxes on the devices it supports.