[asterisk-users] High Pitched Noise

[Eric "ManxPower" Wieling]

Could you be having ECFO?  See:

http://lists.digium.com/pipermail/asterisk-dev/2006-August/022062.html
http://lists.digium.com/pipermail/asterisk-dev/2006-August/022111.html

Rob Schall wrote:
> This is a PRI 24 channel line. We have backup pots lines, but they
> aren't in use. The problem we were having was happening on only a single
> channel or 2.
> 
> Rob
> 
> 
> Noah Miller wrote:
>> Hi Rob -
>>
>>> After about having the server running for about an hour, our callers
>>> occationally hear a high pitched beep that lasts the entire call. In
>>> some cases, the noise doesn't start until a minute or 2 into the call,
>>> while others last the entire call. In some of the more serious cases,
>>> calls are dropped after the noise has occurred as well.
>>>
>>> Another symptom has been really bad static on a specific channel. After
>>> reseating the card to try to fix both this as well as the problem above,
>>> the problem usually goes away, but it seems to come back quicker each
>>> time. Also, the channel that the static occurs on changes after each
>>> reseating (after some time).
>> What kind of PSTN lines are they?  If they're POTS lines, can you plug
>> a regular phone in and test the noise then?  Also have you looked at
>> other hardware devices inside the asterisk box?  I've heard disk
>> drives (hard, floppy, optical) that make loud enough noises that they
>> interfere with analog phone lines.  Do you have another machine to
>> test the card in?