The PHONE_DEVSPECIFIC message is sent to the PHONEEVENT callback function to notify TAPI about device-specific events occurring at the phone. The meaning of the message and the interpretation of the parameters is implementation defined.
PHONE_DEVSPECIFIC
htPhone = (HTAPIPHONE) hPhoneDevice;
dwMsg = (DWORD) PHONE_DEVSPECIFIC;
dwParam1 = (DWORD) DeviceData1;
dwParam2 = (DWORD) DeviceData2;
dwParam3 = (DWORD) DeviceData3;
TAPI sends the PHONE_DEVSPECIFIC message to applications in response to receiving this message from a service provider. The htPhone is translated to the appropriate hPhone as the hDevice parameter at the TAPI level. The dwParam1, dwParam2, and dwParam3 parameters are passed through unmodified.
PHONEEVENT, TSPI_phoneDevSpecific