Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!texbell!vector!telecom-gateway
From: john@jetson.upma.md.us (John Owens)
Newsgroups: comp.dcom.telecom
Subject: Re: Precise Dial Tone & A Tone of the Past: No-Such-Number
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Date: 2 Oct 89 22:02:32 GMT
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On Sep 24, 12:58pm, Larry Lippman wrote:

> Technology in this area went directly from the electromechanical to
> the solid-state.  The one exception was the "no-such-number" tone
> generator, which used vacuum tubes and made its debut around 1940;
> it has been affectionately called the "crybaby tone".  [....]
>
> The last "holdout" I am aware of which used this tone was Rochester
> Telephone, in Rochester, NY, and quite to my surprise I heard this
> tone when I misdialed a toll call to the Rochester area about four
> years ago.  [....]

Actually, this tone (continuous rising for 1 second, continuous
falling for 1 second, etc.) is still in use by C&P Telephone on the
301-867 exchange (West River, MD), for misdialed outgoing calls (e.g.,
dialing a 7-digit number for an exchange not in the local calling
area).  Calls to a non-working 867-xxxx, however, get routed to an AIC
and get an intercept recording!  I haven't tried dialing a 1+ call to
a non-existent area code; I guess that would tell me if the local
switch knows area codes or passes the 1+ call to a smarter tandem.

This switch is being replaced by "the most modern electronic switching
facility in Maryland" this Fall; can anyone tell from the use of the
not-a-number tone what kind of switch I'm on?  It's definitely not a
stepper: touch-tone calls complete in milliseconds.  No "custom
calling features" are available; neither is Centrex, or Equal Access.
Per-call and timed local billing is available.  My guess is a #5
crossbar; reasonable?


John Owens		john@jetson.UPMA.MD.US		uunet!jetson!john
+1 301 249 6000		john%jetson.uucp@uunet.uu.net