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

[Stephen Bosch]

Stephen Bosch wrote:
> 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.

Maybe the power supply is generating this crap.

Hmn. I'm going to test this hypothesis.

-Stephen-