TSPI Line Device Functions

This section contains an alphabetic list of the available line device functions in the Telephony SPI. The information for each function includes the following:

  • A statement of the function's purpose.

  • The correct syntax for the function.

  • A description of the function's parameters, including valid call states.

  • A description of the function's return value.

  • A Remarks section that can include any or all of the following: a list of the valid call states on entry of the function and typical call state transitions when the request completes; a description of which members of large data structures must be filled in by the service provider and which members must have their values preserved intact; and comparison with a corresponding function within TAPI.

  • References to other functions, messages, or data structures.


    The actual states in which a function can be performed may be limited by the capabilities of the service provider. Service providers must set the dwCallFeatures member in the LINECALLSTATUS structure, the dwAddressFeatures member in the LINEADDRESSSTATUS structure, and the dwLineFeatures member in the LINEDEVSTATUS structure to indicate to applications whether or not a function is permitted at that point in time.


This section contains the following TSPI line device functions: