Subject: RE: [Megaco] Comfort Tone?

From: "Kevin Boyle" <[email-masked]>
Date: Thu, 22 Nov 2001 12:15:04 -0500

I believe you are referring to E.182.  E.180 most certainly is a definitive
standard, defining frequency and cadence ranges that are permitted by
international standard.  E.182 lists the nationalized tonesets, which may or
may not be compliant to the E.180 standard.

Kevin

 -----Original Message-----
From: 	Vance Shipley [mailto:[email-masked]] 
Sent:	Wednesday, November 21, 2001 1:22 PM
To:	Paul Long
Cc:	Megaco
Subject:	RE: [Megaco] Comfort Tone?

Paul Long writes:
> It says that comfort tone varies from system to system, although they 
> use a continuous 480Hz tone (I wonder what waveform, though). So there 
> may not be a standard for this tone, unlike dialtone and busy.

As someone who spends a lot of time referencing E.180 "Various Tones used
in National Networks" I would dispute the statement that there was a
standard for dialtone and busy.  We make call progress analysis software
for answer supervision detection.  We find some pretty bizarre tones used
in national networks.

E.180 is an annex to the operational bulletin and is really just a 
collection of statements provided by national operators.  It isn't by
any means definitive, or even remotely accurate, unfortunately.

	-Vance

Vance Shipley
Motivity Telecom Inc.
+1 519 579 5816

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---

From: "Vance Shipley" <[email-masked]>
Date: Thu, 22 Nov 2001 13:20:03 -0500

Kevin Boyle writes:
}
} I believe you are referring to E.182.  E.180 most certainly is a
definitive
} standard, defining frequency and cadence ranges that are permitted by
} international standard.  E.182 lists the nationalized tonesets, which may
or
} may not be compliant to the E.180 standard.

I stand corrected.  The printed copy on my desk is a bit older and
misleadingly
labeled supplement 2 to E.180, which is now called E.182.  I don't use E.180
because it is pretty much irrelevant at least to me.  But just to pick a nit
in
response E.180 is a recommendation, not a standard. :)

	-Vance

---

From: "Vance Shipley" <[email-masked]>
Date: Thu, 22 Nov 2001 13:20:03 -0500

Kevin Boyle writes:
}

	-Vance