[Asterisk-Users] Call quality degradation after time

[Adam Goryachev]

On Thu, 2005-07-21 at 15:56 -0400, Adam Dobrin wrote:
> I'm using Polycom 501's; with stable1.0.8, g729 and a very decent 
> machine; we have a PRI interface to a T1. 
> 
> Many users complain that after a given amount of time, say, 30 or 40 
> minutes on a call, the outside party complains that their sound keeps 
> 'cutting in and out'.  I believe that the incoming sound quality remains 
> fine.
> 
> I had read that there may be some soft of memory issue with the 
> Polycom's... what else could be causing this?  Will auto-rebooting the 
> phones once every few days fix this problem?

We had this problem initially, except it happened from the beginning of
the call. The fix was to tell the phones to prefer alaw and to tell
asterisk to prefer alaw (and not allow anything else). This meant that
we were using alaw from PSTN -> asterisk -> SIP phone ie, everywhere. It
solved the above symptom.

PS, this is in Australia and was with CVS stable 1.0.x from about 12
months ago.

Regards,
Adam