[Asterisk-Users] Line Noise UPDATE - If you've got line noise, read this

[Andrew Kohlsmith]

On April 21, 2005 02:28 am, Andre Normandin wrote:
> I've experiened the noisy line from both my POTS lines (Digit Networks
> X101P cards -- 3 of them to be exact) as well as my VOIP provider
> (Broadvoice)...
>
> The problem has also occured in both directions (I.E I originate the call,
> or someone has called me, again on 2 POTs lines (3rd is fax), as well as on
> my voip line)..

I would *certainly* look at your network or your internet upstream then.  You 
may also want to try Dial(IAX2/echo at switch-1.nufone.net) -- it's a free call; 
it is Nufone's echo() application on their main termination switch.  Call it 
from your SIP phone and talk away (I find doing Darth Vader-style breathing 
is both quiet and gives very good feedback)...  See if you hear sputtering or 
chopping then it very likely has nothing to do with your X101Ps...  You might 
want to remove one to see if that helps as well (i.e. have only one Zap card 
in your system).

As I mentioned earlier, have you taken a look at your internal network and 
your internet uplink?  Are your switches full or half duplex?  Are they 
switches or hubs?  What is the network utilization like when these problems 
are at their worst?  Can you get stats on data rate and collisions from your 
network equipment?  These are all important things to be able to measure to 
try and solve this problem, especially since you have revealed that it 
doesn't seem to have anythign to do with the TDM interface (your X101Ps).

Finally, can you post your 'cat /proc/interrupts' output?

-A.