[Asterisk-Users] Analog FXO Woes Continue

[Jim Van Meggelen]

asterisk-users-bounces at lists.digium.com wrote:
> I've been struggling with a test * install for a couple
> months now in a small office and am just about ready to give
> up on it.  It's not that the system itself is a problem.
> I've got everything (attendant, voicemail, FXS extensions,
> Cisco and Polycom hard-IP phones, and 2 VOIP carriers)
> working except for the frigging analog FXO interfaces.  These
> things are driving me completely mad.  Since this is
> obvioiusly a deal breaker, I'm looking for any more
> suggestions on how I might fet these things working.
> 
> The hitch is pretty clearly the quality of the lines I have
> from BellSouth but I can't get thim to identify anything
> wrong.  I have tried a Digium 1-port FXO card (can't remember
> part number and it's no longer on  their site, hmmm...) as
> well as a Sipura SPA3000.  With both of these interfaces, I'm
> getting consistent mis-dials on outbound calls, broken
> inbound fax-detection, broken DTMF detection in the attendant menus.
> Hours of adjustments to the gains on the Digium card only
> added echo and failed to reduce the offurenc of the other
> issues.  These same two interfaces worked fine on a line at
> my office so I'm pretty sure the issue is with the lines at
> the test site.
> 
> So, what are my options here for interfacing with these
> lines?  Would the channel-bank route affect this?

Another thing to find out is whether there are loading coils on the
circuit. That can cause all kinds of strange problems if you're not
using a purely electromechanical analogue phone.

Did you test these circuits using a regular fax machine plugged directly
into the circuit? Can you test with a good old-fashioned 56K modem; are
you able to connect at a minimum of 28.8K?

The fact is that line impairments can be quite expensive for telcos to
fix. Right or wrong, it is a part of the reason why they'll attempt to
convince you to give up on getting the problem solved.