[Asterisk-Users] RE: Random Disconnects - or ARE they?

[Brent Torrenga]

FOR THE LIST'S BENEFIT, THIS IS MY EMAIL TO THE LOUD PARTY ON OUR SYSTEM,
THANKS FOR ALL YOUR HELP, HOPEFULLY I HAVE THE ISSUE SOLVED:

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Well, I got a series of suggestions as to how to solve your hangup problem.
My favorite suggestion:

>LOL... You could try to explain that he doesn't need to shout to the
>person on the other side, that the telephone transmits the sound by wire,
>and not by air, so he doesn't need to shout to be heard on the other side!
> ;-)

That explanation is actually not far off base! Back in the day, before the
telephone companies digitized their back-bones (the 70's maybe?), a phone
call was actually made by temporarily creating a circuit of copper wire
between the two handsets. This long length of analogue transmission
introduced a certain amount of loss in the signal, depending on how far away
the two endpoints were, how many switching stations were between them, etc.
To overcome the loss of signal, or being heard as "too quiet", one would
need to actually speak up to be adequately heard and to bring their voice
over the line noise.

Anyways, the consensus is that you are loud on the phone, and are scrambling
the "busy detect" routine. The busy detect routine is a piece of code in the
phone card drivers that tries to determine whether or not the phone company
is playing a busy tone on the phone line. I am assuming that over-driving,
or "clipping", the signal voltage does not allow for an accurate analysis of
whether or not the sounds on the line are busy tones or not - that the
system falsely determines that the line is indicating busy and then hangs it
up. The transmit gain of the system could be attenuated so that you cannot
peak the line, precluding this confusion in the system. However, doing so
would cause all conversations to sound that much quieter to the other end of
the line. I suspect it would result in people asking everyone (but you) to
"speak up".

I have disabled the system's busy detect function. I do not think that your
network cable is faulty, there is no indication as such.

Let me know if the problem persists/goes away.

Sincerely,

Brent A. Torrenga
brent.torrenga at torrenga.com

Torrenga Engineering, Inc.
907 Ridge Road
Munster, Indiana 46321-1771

219.836.8918x325 Voice
219.836.1138 Facsimile
www.torrenga.com
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