[asterisk-users] Terrible clicking on T1

[Steve Totaro]

Gleim, Jason wrote:
> Hey All,
>
> 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.
>
> We've been through tech support with Sangoma and we are confident it
> isn't the Sangoma card. We've had the TMDI card replaced in the Nortel
> and we still have the problem. Pure IP calling on the Asterisk box works
> fine so it isn't between the phones and Asterisk. I'm now completely out
> of ideas and I'm looking for some direction to go here. Does anybody
> have any ideas? I desperately need some help.
>
> TIA,
> Jason
>
>
> Asterisk 1.2.18 built by root @ build.trixbox.org on a i686 running
> Linux on 2007-05-08 22:33:23 UTC
>
> # Zaptel Channels Configurations (zaptel.conf)
> #
> loadzone=us
> defaultzone=us
>
> #Sangoma A101 port 1 [slot:14 bus:0 span: 1]
> span=1,0,0,esf,b8zs
> bchan=1-23
> dchan=24
>
>
> ;
> ; Zapata telephony interface
> ;
> ; Configuration file
>
> [trunkgroups]
>
> [channels]
>
> language=en
> context=from-zaptel
> signalling=fxs_ks
> rxwink=300		; Atlas seems to use long (250ms) winks
> ;
> ; Whether or not to do distinctive ring detection on FXO lines
> ;
> ;usedistinctiveringdetection=yes
>
> usecallerid=yes
> hidecallerid=no
> callwaiting=yes
> usecallingpres=yes
> callwaitingcallerid=yes
> threewaycalling=yes
> transfer=yes
> cancallforward=yes
> callreturn=yes
> echocancel=yes
> echocancelwhenbridged=no
> echotraining=800
> rxgain=0.0
> txgain=0.0
> group=0
> callgroup=1
> pickupgroup=1
> immediate=no
>
> ;faxdetect=both
> faxdetect=incoming
> ;faxdetect=outgoing
> ;faxdetect=no
>
> ;Include genzaptelconf configs
> #include zapata-auto.conf
>
> group=1
>
> ;Include AMP configs
> #include zapata_additional.conf
>
>   

Have you done a PRI intense debug on that span?  Maybe you will find 
something there.  Have you looked at the logs?

Obviously, Asterisk/Sangoma is not the problem.  What options do you 
have on the Nortel for the card?  Is there a way to remotely connect to 
the Nortel at a given time and issue the disable/enable for the tdmi 
card (like after it does it's maintenance)?

Can you define the maintenance routines and see if there is something 
that can be disabled that would affect the card?

Thanks,
Steve