Summary:ASTERISK-05777: 'info' indication for North America is incorrect
Reporter:brightidea (brightidea)Labels:
Date Opened:2005-12-04 18:40:04.000-0600Date Closed:2005-12-06 16:44:41.000-0600
Versions:Frequency of
Description:The North American Bellcore SIT sequence is:
985.2Hz, 380ms
1428.5Hz, 380ms
1776.7Hz, 380ms

It should be configured in indications.conf as:
info = !985/380,!1429/380,!1777/380,0

However, it is currently configured as:
info = !950/330,!1400/330,!1800/330,0


The change is minor, but the difference it perceptible.
Comments:By: Tilghman Lesher (tilghman) 2005-12-06 15:45:39.000-0600

Both of the URLs that you cite are actually the same source:  one is a verbatim copy of the other.

I'd feel much more confident about this change if you could dig up a reference to either the official Bellcore or ITU specifications.

By: Tilghman Lesher (tilghman) 2005-12-06 16:09:40.000-0600

Looks like you're going to have to find the BELLCORE spec, since the ITU does not publish a standard for USA SIT.  ITU Operational Bulletin 781 is the latest reference for tones in use, and it does not specify an SIT for either USA or Canada.  E.180 specified the original specs, but did not include a reference on what tones should be used for NANPA.


By: brightidea (brightidea) 2005-12-06 16:19:55.000-0600

Well, if anyone has an extra $455 laying around, the offical document, Feature Specification Document No. 20-06-0500, can be purchased from Bellcore (now Telcordia): http://telecom-info.telcordia.com/site-cgi/ido/newcust.pl?page=idosearch&docnum=GR-674

However, here is a website that lists the tone sequence, citing the offical FSD:
(search for "FSD No. 20-06-0500").

By: Tilghman Lesher (tilghman) 2005-12-06 16:44:41.000-0600

From the page you quoted:

SIT results show the Special Information Tones received in a 6-digit code. SIT tones consist of a sequence of three consecutive tones. The first tone is one of two possible frequencies, and is recorded as tone 1 or 2; the middle tone is one of two different possible frequencies, and is recorded as tone 3 or 4; and the last tone is always a fixed frequency, recorded as tone 5. Each of the three tones can be of two different durations; this is recorded as * (short) or # (long) after each tone digit. Bellcore Feature Specification Document, titled "Special Information Tones (SITs) FSD No. 20-06-0500", details this information. However, the local Telco should be consulted regarding an interpretation of the tone sequences received, as in practice the specifications are not necessarily followed.

I think, in summation, this means there is no single standard for North America in regards to SIT, and that therefore, the current implementation is close enough.

Unless you have a specific issue with the current SIT tones that is causing you problems, I'm going to close out this bug report.