Voice API Programming Guide — June 2005 161
Global Tone Detection and Generation, and Cadenced Tone Generation
13.3.6 Predefined Set of Standard PBX Call Progress Signals
The following information describes the predefined set of standard PBX call progress signals that
are provided by Intel:
•Table19, “Standard PBX Call Progress Signals”, on page 162 lists the predefined, standard,
call progress signals and their signal IDs. The signal IDs can be used with the
dx_playtoneEx( ) function to generate the signal. (The #defines for the signal IDs are located
in the dxxxlib.h file.)
•Figure 20, “Standard PBX Call Progress Signals (Part 1)”, on page 163 illustrates the signals
along with their tone specifications and cadences. The signals were divided into two parts so
they could be illustrated to scale while providing sufficient detail. Part 1 uses a smaller scale
than Part 2. (For this reason, the order of the signals is different than in the tables.)
•Table20, “TN_GENCAD Definitions for Standard PBX Call Progress Signals”, on page 165
lists the TN_GENCAD definitions of the signal cycle and segment definitions for each
predefined call progress signal. These definitions are located in the dxgtd.c file.
•Section 13.3.7, “Important Considerations for Using Predefined Call Progress Signals”, on
page 166 describes what standard was used, how the standard was implemented, information
regarding the signal power levels, usage and other considerations.