asterisk users - Jun 2007 - Noise on FXS ports (Sangoma)

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-

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-

On Thu, Jun 07, 2007 at 04:50:55PM -0600, Stephen Bosch
wrote:
> Tzafrir Cohen wrote:
> > To generate a FXS dialtone without Asterisk, use fxstest (make
fxstest)
> > from the zaptel source directory.
> 
> Can I break this dial tone with DTMF?
No.

-- 
               Tzafrir Cohen       
icq#16849755                    jabber:tzafrir@jabber.org
+972-50-7952406           mailto:tzafrir.cohen@xorcom.com       
http://www.xorcom.com  iax:guest@local.xorcom.com/tzafrir

In this troubleshooting case, it probably is better that there is NO 
dialtone, which would make the hiss easier to hear.
I am curious what the OP found
When Asterisk is stopped, does the hiss continue?
That would help to narrow down the location of the problem
It sure sounds to me as if it is a hardware problem within the card or 
even the module, rather than on the PCI bus or within Asterisk

John Novack


Tzafrir Cohen wrote:
> On Thu, Jun 07, 2007 at 04:50:55PM -0600, Stephen Bosch wrote:
>   
>> Tzafrir Cohen wrote:
>>     
>>> To generate a FXS dialtone without Asterisk, use fxstest (make
fxstest)
>>> from the zaptel source directory.
>>>       
>> Can I break this dial tone with DTMF?
>>     
>
> No.
>
>