The following table lists the call progress tones that are recognisable by default, along with their corresponding identifiers (that may be returned by calls to sm_get_recognised().
| Id | Sequence (Id, min mS, max mS)... | Description |
|---|---|---|
| 1 | (1, 5000, none) | Unobtainable U.K. |
| 2 | (1, 300, 450), (0, 300, 450), (1, 300, 450), (0, 300, 450), | Busy Tone U.K. |
| (1, 352, 608), (0, 352, 608), (1, 352, 608), | Busy Tone E.C. | |
| (6, 400, 600), (0, 400, 600), (6, 400, 600), (0, 400, 600), | Busy Tone U.S. | |
| 3 | (1, 320, 480), (0, 420, 630), (1, 270, 180), (0, 280, 420) | Path Engaged Tone (U.K) |
| 4 | (1, 320, 480), (0, 160, 240), (1, 320, 480) | Ring Tone (U.K.) |
| (1, 320, 480), (0, 1600, 2400), (1, 320, 480) | Ring Tone (U.K.) | |
| (1, 300, 480), (7, 0, 32), (0, 160, 240), (7, 0, 32), (1, 300, 480) | Ring Tone (U.K.) | |
| (1, 300, 480), (7, 0, 32), (0, 1600, 2400), (7, 0, 32), (1, 300, 480) | Ring Tone (U.K.) | |
| (1, 800, 1200), (0, 1600, none) | Ring Tone (E.C./U.S) | |
| (1, 1600, 2400), (0, 4800, 3600) | Long Ring Tone (U.S.) | |
| 5 | (4, 260, 400), (0, 0, 32), (3, 260, 400), (0, 0, 32), (2, 260, 400), | Special Information Tone |
| (4, 304, 456), (0, 0, 32), (3, 304, 456), (0, 0, 32), (2, 304, 456), | Special Information Tone (NC) | |
| (4, 304, 456), (0, 0, 32), (3, 219, 329), (0, 0, 32), (2, 219, 329), | Special Information Tone (IC) | |
| (4, 304, 456), (0, 0, 32), (3, 219, 329), (0, 0, 32), (2, 304, 456), | Special Information Tone (VC) | |
| (4, 304, 456), (0, 0, 32), (3, 304, 456), (0, 0, 32), (2, 219, 329), | Special Information Tone (RO) | |
| 6 | (8, 416, 576), (0, 2240, 3456) | Fax CNG |
| 7 | (9, 2592, 4000) | Fax CED |
| 8 | (7, 3000, none), | Dial tone |
| 9 | (6, 200, 300), (0, 200, 300), (6, 200, 300), (0, 200, 300) | ReOrder (fast busy) |
| 11 | (1, 184, 276), (0, 0, 32), (5, 184, 276) | U.S. Intercept signal |
The ids in the sequence definitions listed above relate to the pre-loaded input tone set for call progress and fax and are enumerated as follows:
| Tone | Purpose |
|---|---|
| 0 | Silence |
| 1 | 350, 400, 425, 440, 450, and 480 Hz |
| 2 | 913.8, 950, and 985.2 Hz (for SIT) |
| 3 | 1370.6, 1400, 1428.5 Hz (for SIT) |
| 4 | 1776.7 and 1800 Hz (for SIT) |
| 5 | 620 Hz (for U.S. intercept) |
| 6 | 480 + 620 Hz (for U.S. busy/reorder) |
| 7 | a dual tone consisting of the same frequencies as 1 above (e.g. 350 + 440 for dial tone) |
| 8 | 1100 Hz (for fax CNG) |
| 9 | 2100 Hz (for fax CED) |