The supplementary phone services functions are listed by category in the following topics. A function is identified as asynchronous if it will indicate completion in a REPLY message to the application. If the function always returns its result to the application immediately, the function is considered synchronous.
| phoneInitializeEx | Initializes TAPI phone abstraction for use by the invoking application. Synchronous. |
| phoneShutdown | Shuts down an application's use of TAPI's phone abstraction. Synchronous. |
| phoneNegotiateAPIVersion | Allows an application to negotiate a TAPI version to use. Synchronous. |
| phoneOpen | Opens the specified phone device, giving the application either owner or monitor privileges. Synchronous. |
| phoneClose | Closes a specified open phone device. Synchronous. |
| phoneGetDevCaps | Returns the capabilities of a given phone device. Synchronous. |
| phoneGetID | Returns a device ID for the given device class associated with the specified phone device. Synchronous. |
| phoneGetIcon | Allows an application to retrieve an icon for display to the user. Synchronous. |
| phoneConfigDialog | Causes the provider of the specified phone device to display a dialog box that allows the user to configure parameters related to the phone device. Synchronous. |
| phoneSetHookSwitch | Sets the hook state of an open phone's hookswitch devices to a specified mode. Asynchronous. |
| phoneGetHookSwitch | Queries the hookswitch mode of a hookswitch device of an open phone device. Synchronous. |
| phoneSetVolume | Sets the volume of a hookswitch device's speaker of an open phone device. Asynchronous. |
| phoneGetVolume | Returns the volume setting of a hookswitch device's speaker of an open phone device. Synchronous. |
| phoneSetGain | Sets the gain of a hookswitch device's mic of an open phone device. Asynchronous. |
| phoneGetGain | Returns the gain setting of a hookswitch device's mic of an open phone. Synchronous. |
| phoneSetDisplay | Writes information to the display of an open phone device. Asynchronous. |
| phoneGetDisplay | Returns the current contents of a phone's display. Synchronous. |
| phoneSetRing | Rings an open phone device according to a given ring mode. Asynchronous. |
| phoneGetRing | Returns the current ring mode of an opened phone device. Synchronous. |
| phoneSetButtonInfo | Sets the information associated with a button on a phone device. Asynchronous. |
| phoneGetButtonInfo | Returns information associated with a button on a phone device. Synchronous. |
| phoneSetLamp | Lights a lamp on a specified open phone device in a given lamp lighting mode. Asynchronous. |
| phoneGetLamp | Returns the current lamp mode of the specified lamp. Synchronous. |
| phoneSetData | Downloads a buffer of data to a given data area in the phone device. Asynchronous. |
| phoneGetData | Uploads the contents of a given data area in the phone device to a buffer. Synchronous. |
| phoneSetStatusMessages | Specifies the status changes for which the application wants to be notified. Synchronous. |
| phoneGetStatusMessages | Returns the status changes for which the application wants to be notified. Synchronous. |
| phoneGetStatus | Returns the complete status of an open phone device. Synchronous. |