[asterisk-users] noisy analog lines

[Ian]

Hi all

I have a small problem here.

We are running Asterisk 1.4.18 and libpri 1.4.3 (how can I check the 
zaptel version again?) on an Intel core 2 duo 1.6Ghz, 2GB ram under 
Ubuntu server.

We have 4 analog line coming into the box via a TDM 800 wildcard with 
echo cancel module and quad fxo modules.

The server has been running smoothly with almost no problems for awhile now.

Recently I started picking up problem with the voice clarity on our end, 
it sounds like a mobile going through a low signal patch. I asked the 
person on the other end and they can hear me loud and clear.

I bumped the txgain up a notch a while back, can it be because of this?

I ran a top and saw that the server only have about 16Mb free ram, can 
this be a possible cause?

My zapata.conf and zaptel.conf are below.

Thanks in advance
Ian
> # less /etc/zaptel.conf
> # Autogenerated by /usr/sbin/zapconf on Fri Feb 29 16:12:07 2008 -- do 
> not hand edit
> # Zaptel Configuration File
> #
> # This file is parsed by the Zaptel Configurator, ztcfg
> #
> # Span 1: WCTDM/0 "Wildcard TDM800P Board 1" (MASTER)
> fxsks=1
> fxsks=2
> fxsks=3
> fxsks=4
> # channel 5, WCTDM/0/4, no module.
> # channel 6, WCTDM/0/5, no module.
> # channel 7, WCTDM/0/6, no module.
> # channel 8, WCTDM/0/7, no module.
>
> # Global data
>
> loadzone        = za
> defaultzone     = za
> # less /etc/asterisk/zapata.conf
> [trunkgroups]
> ; define any trunk groups
>
> [channels]
> ;hardware channels
>
> ;default
> ;groep nommers en rede
> ; 1 => Landlyn
> ; 2 => Selfoon
>
> ; Span 1: WCTDM/0 "Wildcard TDM800P Board 1" (MASTER)
> ;;; line="1 WCTDM/0/0"
> signalling=fxs_ks
> callerid=asreceived
> context=incoming_calls
> group=2
> busydetect=yes
> usecallerid=yes
> hidecallerid=no
> callwaiting=no
> threewaycalling=yes
> transfer=yes
> echocancel=yes
> pulsedial=no
> callprogress=yes
> busycount=5
> subscribecontext=GXP_BLF
> overlapdial=no
> toneduration=200
> txgain=10.0
> rxgain=10.0
> channel => 1
>
> ;;; line="2 WCTDM/0/1 FXSLS"
> signalling=fxs_ks
> callerid=asreceived
> context=incoming_calls
> group=1,2
> busydetect=yes
> usecallerid=yes
> hidecallerid=no
> callwaiting=no
> threewaycalling=yes
> transfer=yes
> echocancel=yes
> pulsedial=no
> callprogress=yes
> busycount=5
> subscribecontext=GXP_BLF
> txgain=10.0
> rxgain=10.0
> overlapdial=yes
> channel => 2
>
> ;;; line="3 WCTDM/0/2"
> signalling=fxs_ks
> callerid=asreceived
> context=incoming_calls
> group=1
> busydetect=yes
> usecallerid=yes
> hidecallerid=no
> callwaiting=no
> threewaycalling=yes
> transfer=yes
> echocancel=yes
> pulsedial=no
> callprogress=yes
> busycount=5
> subscribecontext=GXP_BLF
> txgain=10.0
> rxgain=10.0
> overlapdial=yes
> channel => 3
>
> ;;; line="4 WCTDM/0/3"
> signalling=fxs_ks
> callerid=asreceived
> context=incoming_calls
> group=1
> busydetect=yes
> usecallerid=yes
> hidecallerid=no
> callwaiting=no
> threewaycalling=yes
> transfer=yes
> echocancel=yes
> pulsedial=no
> callprogress=yes
> busycount=5
> subscribecontext=GXP_BLF
> txgain=20.0
> rxgain=10.0
> overlapdial=yes
> channel => 4