The Basic Telephony functions are listed by category in the following tables. A function is identified as asynchronous if it indicates completion in a REPLY message to the application. If the function always returns its result to the application immediately, the function is considered synchronous.
| lineInitializeEx | Initializes the TAPI line abstraction for use by the invoking application. Synchronous. |
| lineShutdown | Shuts down the application's use of TAPI's line abstraction. Synchronous. |
| lineNegotiateAPIVersion | Allows an application to negotiate a TAPI version to use. Synchronous. |
| lineGetDevCaps | Returns the capabilities of a given line device. Synchronous. |
| lineGetDevConfig | Returns configuration of a media stream device. Synchronous. |
| lineGetLineDevStatus | Returns current status of the specified open line device. Synchronous. |
| lineSetDevConfig | Sets the configuration of the specified media stream device. Synchronous. |
| lineSetStatusMessages | Specifies the status changes for which the application needs to be notified. Synchronous. |
| lineGetStatusMessages | Returns the application's current line and address status message settings. Synchronous. |
| lineGetID | Retrieves a device ID associated with the specified open line, address, or call. Synchronous. |
| lineGetIcon | Allows an application to retrieve an icon for display to the user. Synchronous. |
| lineConfigDialog | Causes the provider of the specified line device to display a dialog box that allows the user to configure parameters related to the line device. Synchronous. |
| lineConfigDialogEdit | Displays a dialog box allowing the user to change configuration information for a line device. Synchronous. Version 0x00010004. |
| lineGetAddressCaps | Returns the telephony capabilities of an address. Synchronous. |
| lineGetAddressStatus | Returns current status of a specified address. Synchronous. |
| lineGetAddressID | Retrieves the address ID of an address specified using an alternate format. Synchronous. |
| lineOpen | Opens a specified line device for providing subsequent monitoring and/or control of the line. Synchronous. |
| lineClose | Closes a specified opened line device. Synchronous. |
| lineTranslateAddress | Translates between an address in canonical format and an address in dialable format. Synchronous. |
| lineSetCurrentLocation | Sets the location used as the context for address translation. Synchronous. |
| lineSetTollList | Manipulates the toll list. Synchronous. |
| lineGetTranslateCaps | Returns address translation capabilities. Synchronous. |
| lineGetCallInfo | Returns fixed information about a call. Synchronous. |
| lineGetCallStatus | Returns complete call status information for the specified call. Synchronous. |
| lineSetAppSpecific | Sets the application-specific field of a call's information structure. Synchronous. |
| lineMakeCall | Makes an outbound call and returns a call handle for it. Asynchronous. |
| lineDial | Dials (parts of one or more) dialable addresses. Asynchronous. |
| lineAnswer | Answers an incoming call. Asynchronous. |
| lineSetNumRings | Indicates the number of rings after which incoming calls are to be answered. Synchronous. |
| lineGetNumRings | Returns the minimum number of rings requested with lineSetNumRings. Synchronous. |
| lineSetCallPrivilege | Sets the application's privilege to the privilege specified. Synchronous. |
| lineDrop | Disconnects a call, or abandons a call attempt in progress. Asynchronous. |
| lineDeallocateCall | Deallocates the specified call handle. Synchronous. |
| lineHandoff | Hands off call ownership and/or changes an application's privileges to a call. Synchronous. |
| lineGetNewCalls | Returns call handles to calls on a specified line or address for which the application does not yet have handles. Synchronous. |
| lineGetConfRelatedCalls | Returns a list of call handles that are part of the same conference call as the call specified as a parameter. Synchronous. |
| lineTranslateDialog | Displays a dialog box allowing the user to change location and calling card information. Synchronous. Version 0x00010004. |
| lineGetCountry | Retrieves dialing rules and other information about a given country. Synchronous. Version 0x00010004. |
The following two functions are used only in support of Assisted Telephony.
| lineRegisterRequestRecipient | Registers or deregisters the application as a request recipient for the specified request mode. Synchronous. |
| lineGetRequest | Gets the next request from the Telephony dynamic link library. Synchronous. |