TSPI_phoneGetExtensionID function (tspi.h)

Article
10/05/2021

The TSPI_phoneGetExtensionID function retrieves the extension identifier that the service provider supports for the indicated phone device.

Syntax

LONG TSPIAPI TSPI_phoneGetExtensionID(
  DWORD              dwDeviceID,
  DWORD              dwTSPIVersion,
  LPPHONEEXTENSIONID lpExtensionID
);

Parameters

dwDeviceID

The phone device to be queried.

dwTSPIVersion

Specifies an interface version number that is negotiated for this device using TSPI_phoneNegotiateTSPIVersion. This function operates according to the interface specification at this version level.

lpExtensionID

A pointer to a structure of type PHONEEXTENSIONID. If the service provider supports provider-specific extensions, it fills this structure with the extension identifier of these extensions. If the service provider does not support extensions, it fills this structure with all zeros. An extension identifier of all zeros is not a legal extension identifier, since the all-zeros value is used to indicate that the service provider does not support extensions.

Return value

Returns zero if the function succeeds, or an error number if an error occurs. Possible return values are as follows:

PHONEERR_INCOMPATIBLEAPIVERSION, PHONEERR_RESOURCEUNAVAIL, PHONEERR_NODRIVER, PHONEERR_OPERATIONFAILED, PHONEERR_NOMEM, PHONEERR_OPERATIONUNAVAIL.

Remarks

This function is typically called by TAPI in response to an application calling the phoneNegotiateAPIVersion function. The result returned by the service provider should be appropriate for use in a subsequent call to TSPI_phoneNegotiateExtVersion.

Requirements

Requirement	Value
Target Platform	Windows
Header	tspi.h