Voice API Programming Guide — June 2005 163
Global Tone Detection and Generation, and Cadenced Tone Generation
Figure 20. Standard PBX Call Progress Signals (Part 1)25
CP_RINGBACK2
440 + 480 Hz
-16 dB
≈
100
≈
400
CP_RINGBACK1
440 + 480 Hz
-16 dB ≈
300
≈
100
CP_BUSY
480 + 620 Hz
-21 dB 50
50
50
50
25
CP_REORDER
480 + 620 Hz
-21 dB 25
25
25
25 25
25
CP_DIAL
350 + 440 Hz
-16 dB
Continuous
CP_RINGBACK2_CALLWAIT
a) 440 + 480 Hz b) 440 Hz
-16 dB 400
20200
≈
440+480
Hz
440
Hz
CP_RINGBACK1_CALLWAIT
a) 440 + 480 Hz b) 440 Hz
-16 dB ≈
300
≈
100 20
440
Hz
440+480
Hz