call progress tones: U.S. and Canada

Table 1. Tone parameter values (U.S./Canada).
This table describes the characteristics of U.S. and Canadian call progress tones. For each different tone name, the minimum, nominal, and maximum frequency in Hertz is listed, followed by the minimum and maximum power ratios in decibels. Continuous tones are identified, and for discontinuous tones, details of the minimum, nominal, and maximum durations in milliseconds that the tone is on and off are listed.
Tone Name	Tone Label	Tone Type	Frequency n (Hz)				Level (dBm)		Time On (ms)			Time Off (ms)
Tone Name	Tone Label	Tone Type	n	Min	Nom	Max	Min	Max	Min	Nom	Max	Min	Nom	Max
Primary Dial Tone	Dial, Primary	Dial	1	319	350	382	-33	-9	Continuous tone
Primary Dial Tone	Dial, Primary	Dial	2	400	440	480	-33	-9	Continuous tone
Secondary Dial Tone	Dial, Secondary	Dial	1	478	525	572	-33	-9	Continuous tone
Secondary Dial Tone	Dial, Secondary	Dial	2	601	660	719	-33	-9	Continuous tone
Ring Tone	Ring	Ring	1	400	440	480	-40	-9	1680	2000	2320	3380	4000	4620
Ring Tone	Ring	Ring	2	437	480	523	-40	-9	1680	2000	2320	3380	4000	4620
Busy Line Tone	Busy, Line	Busy	1	437	480	523	-40	-9	400	500	580	400	500	580
Busy Line Tone	Busy, Line	Busy	2	564	620	676	-40	-9	400	500	580	400	500	580
Busy Network Tone	Busy, Network	Network Busy	1	437	480	523	-40	-9	180	250	300	180	250	300
Busy Network Tone	Busy, Network	Network Busy	2	564	620	676	-40	-9	180	250	300	180	250	300

Special information tones: U.S. and Canada

This section defines the terms used in Table 2.

Reorder - SIT1 (RO')

This SIT indicates generalized network error conditions across intraLATA (local access and transport area) networks. An example returned announcement is: “We're sorry, your call did not go through. Will you please try your call again”.

Vacant Code - SIT2 (VC)

This SIT indicates that a number was dialled incorrectly. An example returned announcement is “We're sorry, your call cannot be completed as dialled. Please check the number and dial again”.

No Circuit - SIT3 (NC')

This SIT indicates facility trouble that prevents calls from being completed. An example returned announcement is “We're sorry, due to telephone company facility trouble, your call cannot be completed at this time. Please try again later”.

Intercept - SIT4 (IC)

This SIT indicates that the number dialled has been disconnected. An example returned announcement is “We're sorry, you have reached a number that has been disconnected or is no longer in service. If you feel you have reached this recording in error, please check the number and try your call again”.

Reorder - SIT5 (RO')

This SIT indicates network error conditions relating to long-distance carriers. An example returned announcement is “We're sorry, due to network difficulties, your long-distance call cannot be completed at this time. Please try your call again later”.

No Circuit - SIT6 (NC")

This SIT indicates facility trouble that prevents calls from being completed. An example returned announcement is “We're sorry, all circuits are busy now. Will you please try again later”.

Ineffective Other - SIT7 (IO)

This SIT indicates that a call cannot be completed as dialled because of restrictions in the telephone being used. An example returned announcement is “We're sorry, you call cannot be completed as dialled from the phone you are using. Please read the instruction card and dial again”.

Table 2. Special information tone (SIT) parameter values (U.S./Canada).
This table describes the characteristics of U.S. and Canadian special information tones. For each different tone name (Dial Tone, Ring Tone, and Busy Tone) the minimum, nominal, and maximum frequency in Hertz is listed, followed by the minimum and maximum power ratios in decibels. Continuous tones are identified, and for discontinuous tones, details of the minimum, nominal, and maximum durations in milliseconds that the tone is on and off are listed.
Tone Name	Tone Label	Tone Type	Frequency n (Hz)				Level (dBm)		Time On (ms)			Time Off (ms) ¹
Tone Name	Tone Label	Tone Type	n	Min	Nom	Max	Min	Max	Min	Nom	Max	Time Off (ms) ¹
Reorder	SIT1(RO')	Network Busy	1	873	914	955	-40	-9	220	274	320	—
			2	1365	1429	1493	-40	-9	340	380	460	—
			3	1620	1770	1857	-40	-9	340	380	460	—
Vacant Code	SIT2 (VC)	Other	1	941	985	1029	-40	-9	340	380	460	—
			2	1309	1371	1433	-40	-9	220	274	320	—
			3	1620	1770	1857	-40	-9	340	380	460	—
No Circuit	SIT3 (NC')	Network Busy	1	941	985	1029	-40	-9	340	380	460	—
			2	1365	1429	1493	-40	-9	340	380	460	—
			3	1620	1770	1857	-40	-9	340	380	460	—
Intercept	SIT4(IC)	Other	1	873	914	955	-40	-9	220	274	320	—
			2	1309	1371	1433	-40	-9	220	274	320	—
			3	1620	1770	1857	-40	-9	340	380	460	—
Reorder	SIT5 (RO')	Network Busy	1	941	985	1029	-40	-9	220	274	320	—
			2	1309	1371	1433	-40	-9	340	380	460	—
			3	1620	1770	1857	-40	-9	340	380	460	—
No Circuit	SIT6 (NC")	Network Busy	1	873	914	955	-40	-9	340	380	460	—
			2	1309	1371	1433	-40	-9	340	380	460	—
			3	1620	1770	1857	-40	-9	340	380	460	—
Ineffective Other	SIT7 (IO)	Other	1	873	914	955	-40	-9	340	380	460	—
			2	1365	1429	1493	-40	-9	220	274	320	—
			3	1620	1770	1857	-40	-9	340	380	460	—
Special Information Tones each consist of a sequence of three frequencies with no off-time between them.

PBX-specific tones

Table 3. Tones specific to AT&T and ROLM PBXs.
This table describes the characteristics of U.S. and Canadian PBX-specific tones. For each different tone name (Dial Tone, Ring Tone, and Busy Tone) the minimum, nominal, and maximum frequency in Hertz is listed, followed by the minimum and maximum power ratios in decibels. Continuous tones are identified, and for discontinuous tones, details of the minimum, nominal, and maximum durations in milliseconds that the tone is on and off are listed.
Tone Name	Tone Label	Tone Type	Frequency n (Hz)				Level (dBm)		Time On (ms)			Time Off (ms)
Tone Name	Tone Label	Tone Type	n	Min	Nom	Max	Min	Max	Min	Nom	Max	Min	Nom	Max
AT&T PBX Dial	Dial PBX AT&T	Dial	1	400	440	480	-27	-13	Continuous tone
Rolm Dial Tone	Dial Tone Rolm 9005	Dial	1	440	480	520	-33	-9	Continuous tone
Rolm Dial Tone	Holding Dial Tone Rolm 9005	Dial	1	260	300	340	-33	-9	Continuous tone
Rolm Ring	Ring, Rolm	Ring	1	400	440	480	-40	-9	820	1000	1160	2520	3000	3460
Rolm Ring	Ring, Rolm	Ring	2	437	480	523	-40	-9	820	1000	1160	2520	3000	3460
Rolm Busy, Do Not Disturb	Busy, Rolm DND	Busy	1	701	770	839	-33	-9	400	500	580	400	500	580
Rolm Busy, Do Not Disturb	Busy, Rolm DND	Busy	2	801	880	959	-33	-9	400	500	580	400	500	580
Rolm Error Tone ¹	Error Tone Rolm 9005	Other	1	280	300	320	-35	-5	180	250	320	—
			2	460	480	500	-35	-5	180	250	320	—
			3	280	300	320	-35	-5	180	250	320	—
Rolm Error Tone	Error Tone Rolm 9005	Other	1	460	480	500	-35	-5	180	250	320	—
			2	280	300	320	-35	-5	180	250	320	—
			3	460	480	500	-35	-5	180	250	320	—
Rolm Error Tone 2	Error Tone 2 Rolm 9006	Other	1	400	440	480	-35	-5	180	250	320	—
			2	564	620	676	-35	-5	180	250	320	—
			3	400	440	480	-35	-5	180	250	320	—
Rolm Error Tone 2	Error Tone 2 Rolm 9006	Other	1	564	620	676	-35	-5	180	250	320	—
			2	400	440	480	-35	-5	180	250	320	—
			3	564	620	676	-35	-5	180	250	320	—
Error tones alternate between two tones (300 Hz and 480 Hz for the Rolm 9005 or 440 Hz and 620 Hz for the Rolm 9006) at a rate of 250 ms, continuously, that is tone1-tone2-tone1-tone2... Two tritone entries are used for each type of tone to recognize tones starting with either the first or the second of the two tones.

Call progress tones: U.S. and Canada

Special information tones: U.S. and Canada

PBX-specific tones