Functions

This section contains an alphabetical list of the line device, phone device, and assisted telephony functions in the Telephony applications programming interface (API).

The information for each function includes a list of the valid call states on entry of the function and typical call state transitions when the request completes. Note that the actual states in which a function may be performed may be further limited by the capabilities of the service provider. Applications must check the dwCallFeatures field in the LINECALLSTATUS1O11BWV structure, the dwAddressFeatures field in the LINEADDRESSSTATUSGM12S3 structure, and the dwLineFeatures field in the LINEDEVSTATUS54R1YX5 structure to determine whether or not a function is permitted at that point in time.