asterisk users - May 2008 - Loud, obnoxious screech heard during ring

Hi,
Sometimes when making calls from a SIP phone, instead of the normal
ring tone, we hear a very loud, high pitched screech instead.
Does anyone know what may cause this? It does happen on every phone
call, but intermittently. Is it a QoS issue? Asterisk problem?

Thanks.

On Mon, May 26, 2008 at 4:58 PM, James Lamanna <jlamanna at gmail.com>
wrote:
> Hi,
> Sometimes when making calls from a SIP phone, instead of the normal
> ring tone, we hear a very loud, high pitched screech instead.
> Does anyone know what may cause this? It does happen on every phone
> call, but intermittently. Is it a QoS issue? Asterisk problem?
>
> Thanks.
>
We need more details to narrow it down.

I have seen this on a bad FXO port on the card itself, if it is not
the first one and depending on how many calls it takes to hit that
port or line, would dictate when the screech was heard.  To determine
the port, I dialed in each analog line until I found the one with the
noise.  Then I moved the line to another port to rule out the telco.
Then I swapped out the FXO module, still had the screech, then I
swapped out the card.  All better.

I have had really bad screeching from Citel Definity equipment too.

Are you using analog, PRI, or all VoIP?  Is it just the ring that
screeches or the whole call?

Thanks,
Steve T