[asterisk-users] Noise on FXS ports (Sangoma)

[Stephen Bosch]

Hi:

I have a Sangoma A200 card installed in a server with two FXO modules
and one FXS module.

Analog sets connected to the FXS module have a "squeaky static" -- it's
like static mixed with the sound of someone vigorously cleaning a window
a few doors down.

In other words, it's not a classic static noise, but it is noise, and
it's distracting. Remote callers can hear this noise.

I have, by turns:

- Tested the line with the same analog sets plugged in at the
demarcation point. No noise. (None of the SIP devices in this
configuration have this noise for outgoing calls, so I'm sure it's got
something to do with the FXS module).

- Plugged the known good analog sets straight into the server

- Moved the FXS module off the REMORA daughtercard to the main card

- Replaced the FXS module with a new one

- Run the server off of battery power, to see if the noise is garbage
leaking in off the AC

- Turned off the PoE midspan

The next thing I'm going to try is turning off the switch it's plugged
into. When that is done, I'll have done everything short of move the
server to a different location.

I have already contacted Sangoma about this, but we're busy dealing with
another problem and they're swamped, so things are going slowly.

In the meantime, has anybody else had this kind of noise with FXS
modules of *any* stripe?

-Stephen-