[asterisk-users] Terrible clicking on T1

[Gleim, Jason]

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