Sources of Log Information

Information useful to call logging (which is saved by TAPI) originates in the following sources, and is placed in the LINECALLINFO data structure.

• In an application's call of the initialization function, lineInitializeEx, it provides information such as the application's name. An application should ensure that the information it provides with the initialization command is accurate so that its activities are reflected correctly in the call log.
• The LINECALLPARAMS data structure, used in the lineMakeCall function, stores information such as the name of the called party, the originating address, and the destination address. This structure is passed to TAPI by any application that originates a call.
• The service provider supplies many items that can be logged such as the caller's ID.
• The LINE_CALLSTATE messages that pertain to a given call are an important source of logging information, indicating whether the call successfully connected or was abandoned because of a busy signal, no answer, network congestion, or other causes.

The start time, end time, and duration of a call are not recorded by TAPI. A logging application that wants to log this information must record the time by checking the system clock when certain LINE_CALLSTATE messages (such as CONNECTED, DISCONNECTED, and IDLE) are received, and then derive the related time log information.