Windows Mobile 6.5
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This function is used as a general extension mechanism to enable a Telephony API implementation to provide features not described in the other TAPI functions. The meanings of these extensions are device specific.

LONG WINAPI phoneDevSpecific(
  HPHONE hPhone,
  LPVOID lpParams,
  DWORD dwSize 


Handle to a phone device.


Pointer to a memory area used to hold a parameter block. Its interpretation is device specific. The contents of the parameter block are passed unchanged to or from the service provider by TAPI.


Size, in bytes, of the parameter block area.

Returns a positive request identifier if the function is completed asynchronously or a negative error number if an error occurs. The dwParam2 parameter of the corresponding PHONE_REPLY message is zero if the function succeeds or it is a negative error number if an error occurs. The following table shows the return values for this function.

Value Description


The handle to the phone device is invalid.


Not enough memory is available.


The pointer is invalid.


The resources are unavailable.


The operation is unavailable.


A parameter is uninitialized.


The operation failed.

Additional return values are device specific.

This operation provides a generic parameter profile. The interpretation of the parameter block is device specific. Indications and replies that are device specific should use the PHONE_DEVSPECIFIC message.

A service provider can provide access to device-specific functions by defining parameters for use with this operation. Applications that want to make use of these device-specific extensions should consult the device-specific (vendor-specific) documentation that describes which extensions are defined. Typically, an application that relies on these device-specific extensions is not portable to work with other service-provider environments.

This function is for TAPI version 2.0 and later.

Windows Embedded CEWindows CE 3.0 and later
Windows MobileWindows Mobile Version 5.0 and later

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