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

[Stephen Bosch]

Hi, Jorge:

Jorge Mendoza wrote:
>>   
> Never experienced with FXS modules on a PC with  Asterisk. However we
> have experienced that kind of problems on legacy PBX without a good
> ground. If you replace the system with a analogue set and have not
> noise, then a ground current is generated in your system, probably
> originated at FXO side. Have you tested the PC isolated, with not lines
> and not switches? just the FXS calling the voicemail?

No, I haven't gone that far yet, but it might be worth trying.

One question I have: if this turned out to be the cause, what could I do
to clean up the ground? There are so many elements -- the power supply
ground, the telephone lines, the network cable ground, etc.

-Stephen-