[geeks] debugging house phones

[Charles Shannon Hendrix]

I am trying to debug someone's house phones.

The house has two phones lines.

Each phone jack has a seperate line to the TNI on the back of the house.

The telephone network interface (TNI) is a Kertel 4601.  It has two line
modules installed.  Each internal connection point on the customer side
is connected to the telco side with a short RJ-11 patch cord.  It's a
simple physical interface box.

Three house jacks go to line A, one goes to line B.

Line A has on it:

    * POTS phone
    * POTS phone
    * 5.8GHz V-Tech wireless phone system with three handsets

Again, each of those is on a seperate line to the TNI.

Line B has on it:
    
    * modem
    * POTS phone, connected via the modem, which disconnects it during a
      call

The problems they have been having:

When a call comes in one line A, the modem on line B hangs up and
redials.  Not always, but usually.  If using a POTS phone on line A, you
can hear the modem on line B dialing and connecting.  You can't hear
the continuous modem signal though, once it has established connection.
Just picking up line A does no harm to the modem connection on line B,
even if you make loud noises.

Sometimes the phones on line A go off-hook.  If you pick up a POTS
phone, you can hear the phone company local office saying "if you'd like
to make a call..." and so on.  Eventually the local office disables
dial-tone for about five minutes.  This problem is often solved by
taking the wireless base unit offline. However, they still see dropped
modem calls as above, though perhaps not as often.

When line A receives a call, sometimes the ring is incomplete.  Instead
of a solid ring, you get just a little ding.  If you pick up the phone,
it may or may not be connected to the caller.  It usually is.  It's as
if there were not enough ring voltage.

Notes and questions:

The modem on line B generally gets good connections.  Voice calls are
clear as well.

Each internal jack->TNI line is independent, and appears to be
working fine.  I can't detect voltage across any pair of lines with a
multimeter.  I have no equipment for further testing.

I don't think the internal wiring is damaged.  Each jack gets a good
solid dialtone.  The problems *almost* go away if only one jack is used,
but it doesn't seem to matter which one.

The phone company says that because any one phone is able to get a
dialtone, the problem has to be the building wiring.

I have debugged problems in the past where this was not true.  Internal
jacks got a good dialtone, but the problem still turned out to be on the
telco side.  It took a lot of phone calls and bitching to get them to
fix it.

Regarding "technical support": Everything is a non-human, automated
'help' system, at least it is with Verizon in eastern Virginia.  It
tells you to perform certain tests, and if they work, that's pretty much
the end of the call.

The only sure test I know of is to connect their modem and one POTS
phone directly to the telco side, and then call line A to see if
the modem hangs up and if there is inteference.  Right now, that's
physically difficult, and I'd have to buy a long cable and some
alligator clips.

What else could I check on?

Anyone know of problems caused by V-Tech 5.8GHz wireless phones?

Anyone know of some numbers for Verizon that bypass the standard help
desk?

Is there anything else about the internal wiring that I can check?









-- 
shannon "AT" widomaker.com -- ["The strength of the Constitution lies
entirely in the determination of each citizen to defend it.  Only if every
single citizen feels duty bound to do his share in this defense are the
constitutional rights secure." -- Albert Einstein]