[PLUG-TALK] Known-good Touch Tone test service numbers?

Keith Lofstrom keithl at kl-ic.com
Tue Feb 2 00:11:55 UTC 2021


On Mon, Feb 01, 2021 at 01:39:55AM -0800, wes wrote:
> I wouldn't call it a "DTMF test service" exactly but you could get pretty
> close by calling a number that you know is answered by an auto-attendant,
> with lots of options you can press. The response you hear will indicate
> which number it thinks you pressed, even if that response isn't an explicit
> "you pressed number foo".

Been there.

Indeed, organizations with phone menus that do (or don't) 
respond to touchtone presses are the reason why I'm looking
for a more diagnostic DTMF key-response dialin number. 

The testcall.com site I mentioned claimed to respond with
a spoken numeral for the buttons pressed on the phone
keypad.  It did not respond to many different analog phones
plugged into two different outgoing POTS-to-digital lines.
It also did not respond to our cell phones, so I presume
that site is busted.  Other websites suggested by google
search are no longer active.  Hence my plug-talk question.

Anyway, I prefer to KNOW, in DETAIL, the quality of the
delivered DTMF signal, not just "maybe" or "maybe not".

Digitizing phone channels, in the Covid/Zoom/telework era
of oversubscribed streaming video bandwidth, probably leads
to dropouts and quality loss.  Delivering an uninterrupted
two-frequency beep - with steady amplitude and timing -
may be more difficult lately.  I doubt that typical
"it worked when we deployed it five years ago" phone
software quality assurance "techniques" are robust enough
for current network conditions.  

My ideal test would be a dial-in number producing a voice
response, but also creating a web page or email providing
detailed quality measures for the tones entered.

Not just whether the tones pass or fail some detection
threshold, but also numeric measures of the quality of the
tones ( duration, amplitude for both tones in the DTMF
number matrix, noise level, frequency stability, etc. ),
leading to suggestions for problem causes and cures.  

The goal is measurements robust and diagnostic enough to
get the attention of service providers with unacknowledged
problems - and the regulatory agencies overseeing them. 

If I had abundant spare time, I would modify an Asterisk
system to do this detailed testing, and offer it as a paid
web service, (a dime a test?).  The payment process would
be more complicated than the measurements and diagnostics;
perhaps ads for telephones and services could pay for it.

(Your X phone is doing XXX.  Buy a problem-free Y phone!)

Keith

-- 
Keith Lofstrom          keithl at keithl.com



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