[asterisk-users] Terrible clicking on T1

[Jay R. Ashworth]

On Thu, Aug 09, 2007 at 11:39:38AM -0400, Gleim, Jason wrote:
> I have an Asterisk box connected to a Nortel Option 11C via a T1. In the
> Asterisk box we have a Sangoma A101C and in the Nortel we have a TMDI
> card. The Nortel is also hooked to the PSTN via a T1 on a different
> NTAK09 PRI card. I've included the Zapata.conf and zaptel.conf files
> below.
> 
> Our issue is that when a call is sent over the tie line between the two
> systems, the audio on the Asterisk side is terrible. There are rapid
> 'clicks' on it similar to when you have a cell phone close to an analog
> phone or a set of computer speakers. The clicks start as soon as the
> audio channel is opened (when I start to get rings) and it only affects
> the Asterisk side of the call. But, it affects both inbound and outbound
> audio on that side. On the Nortel side, the audio they hear is soft and
> distorted. On the Asterisk side, the audio they hear is full of the
> clicking but broken thru when the caller speaks. It's almost like the
> 'silence packets' are being interpreted wrong by Asterisk. If I put the
> Asterisk box on the T1 for the PSTN, it works perfect.
> 
> The best part of all this... if we disable the TMDI card in the Nortel
> and then re-enable it, the audio is pristine... until the Nortel runs
> it's nightly maintenance routines. Then the noise is back the next day.
> We can always clear the problem with the disable/re-enable trick but it
> always come back after maintenance.

My bet is clock-slip due to a fight over who's clocking the line.

Cheers,
-- jra
-- 
Jay R. Ashworth                   Baylink                      jra at baylink.com
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