The TSPI_providerCreatePhoneDevice function is called by TAPI in response to receipt of a PHONE_CREATE message from the service provider, which allows the dynamic creation of a new phone device.
LONG TSPIAPI TSPI_providerCreatePhoneDevice(
DWORD dwTempID,
DWORD dwDeviceID
);
Returns zero if the request succeeds or an error number if an error occurs. Possible return values are:
LINEERR_BADDEVICEID, LINEERR_NOMEM, LINEERR_OPERATIONFAILED.
When TAPI receives a PHONE_CREATE message from a service provider, it calls this function (it never calls this function spontaneously). TAPI adds 1 to the number of devices of that type, and passes the resulting new, unused device identifier as the dwDeviceID parameter to this function. It also passes in the function the dwParam2 parameter from the PHONE_CREATE message as dwTempID. Adding the new device to the end of the device list is likely to produce noncontiguous device identifiers for the service provider; service providers that support dynamic device creation must also support noncontiguous device identifiers.
If the service provider recognizes the dwTempID parameter and succeeds in setting up the structures and such that it needs to support the new device, it saves off the dwDeviceID, and returns SUCCESS. If this function is unsuccessful, TAPI doesn't add the device, and there are no negative effects (the PHONE_CREATE message is ignored). If this function completes successfully, TAPI informs applications of the availability of the new device using PHONE_CREATE or PHONE_STATE (PHONESTATE_REINIT) messages.
Older service providers that do not export this function, however, also should not send PHONE_CREATE messages, which means TAPI would not try to call this function.