| Platform SDK: TAPI |
The Extended Telephony functions are listed by category in the following tables.
| lineNegotiateExtVersion | Allows an application to negotiate an extension version to use with the specified line device. Asynchronous. |
| lineDevSpecific | Gives service providers access to device-specific features not offered by other TAPI functions. Synchronous. |
| lineDevSpecificFeature | Sends device-specific switch features to the switch. Asynchronous. |
| phoneDevSpecific | Device-specific escape function to allow vendor-dependent extensions. Asynchronous. |
| PhoneNegotiateExtVersion | Allows an application to negotiate an extension version to use with the specified phone device. Synchronous. |