A service provider sends a LINE_REMOVE message to TAPI when it desires to disable an existing line device. This can occur when the removal of the device from the system (in a permanent way) is detected by Plug and Play or through a control panel or other user interface. It should not be used when a device is temporarily disconnected, such as if the device is a PCMCIA card that is extracted (use LINEDEVSTATE_DISCONNECTED or _OUTOFSERVICE in this situation).

When the message is received, TAPI closes the line device (if it is not already closed) by calling TSPI_lineClose, and sends LINE_CLOSE to all applications that have the line open; if any calls are active, TSPI_lineCloseCallis called on each of them prior to TSPI_lineClose. After processing the message, TAPI does not call the service provider referencing the removed device's dwDeviceID. TAPI returns LINEERR_NODEVICE to any application that attempts to reference the removed dwDeviceID.

After TSPI_providerShutdownhas been called, the service provider can renumber its devices to remove any numbering gaps left by the device removal, so that when TSPI_providerEnumDevicesis subsequently called, installed devices are contiguously numbered. The service provider should not reuse the dwPermanentLineIDthat had been assigned to the device, for as long as possible.

The LINE_REMOVE mechanism is intended to be used only if devices are removed while the service provider is active (for example, between TSPI_providerInitand TSPI_providerShutdown).

This message is sent to TAPI's LINEEVENTcallback entry point. The service provider receives a pointer to this callback in the TSPI_providerEnumDevicesfunction and in each TSPI_lineOpenfunction; the LINE_REMOVE message can be sent to the LINEEVENTcallback function given to any open line or at startup.

Older service providers are not expected to send this message. If they do, the message is treated in the same manner as described earlier for new service providers.