Everyone - thought I would pass on a useful piece of information.
Finally got a solution to my phantom ringing problem.
Problem - the zhone is triggered into detecting ringing by the Automatic
Line Insulation Tests (ALIT or LIT) run nightly automatically by the telco.
Here it is twice between 8pm and 9pm on my particular lines.
My first approach before I knew specifically the buzzword for the testing,
was to call up repair and describe the problem, and they denied knowledge
of any such tests, sent a tech out to test the line - surprise he found
nothing since there is nothing physically wrong with the line. I got
frustrated and gave up at the time.
A few months of annoying ringing go on, I get pissed off again and start
searching and find out indeed there is automated testing going on all the time.
Now granted the real problem is the zhone itself being oversensitive, but I
take the view that you can always fix shit hardware with the right software.
After writing off the telco (Bell Canada) as morons, I attempt to find a
solution in asterisk - ring debounce looks right so I investigate the
zaptel libs. Mark chimes in about how could this be possible yada yada.
After investigation I find the debounce set to 500ms, but basically ignored
and treated as an on/off value - implementation of which still seems pretty
strange, but I am convinced it is not doing much, if any, debouncing of the
RBS on the t1.
I decide to give up on that since it looks like I would have to redo a
large part of the driver to build in the hysterisis I need into the
signalling bits.
Why this problem is so vexing is I have one line that rings through to a
phone, and then transfers to vm, since the line never actually rung, there
is no disconnect supervision on the hangup either, so I get an infinitely
long voicemail that fills up the whole hd. (yeah I know there are solutions
to that but might as well fix the real issue right ?)
So I get on the phone to the telco again today with the attitude I usually
do when I am pissed off at them, that I will not hang up till they do what
I want. Procedure - get the person's name, then insist they solve your
problem for you. Be prepared for a long time on hold (3hrs is my record).
They will not just hang up on you once you have their name.
So I start in today saying I want the LIT cancelled for the 4 lines I have
and I am not taking no for an answer since it is so annoying. 45min of hold
and transferring later, I am talking to a guy that knows exactly what I am
talking about and helps me out.
In this area you can even be more specific and say you want an "NLT"
record
added to your line. I suspect this is related to the software for the
DMS-100 switch so it is likely the same in most places in North America.
If this helps even one more person with a zhone and this annoying problem,
it was worth writing it all down.
