asterisk users - Jan 2006 - Asterisk 1.2.1 + TDM400P + fax machine unreliable ?

Hi,

I have a running asterisk 1.2.1 (bristuffed) with a TDM400 Board. Connected
to 1 port is am ordanary Fax Machine. Everything 'seems' to work,
however receiving faxes is very unreliable.

Sometimes I receive a normal page, without problems. Sometimes
half of a page and the rest is scrambled, but most often, I receive
nothing and the other site reports a Fax error...

The Fax machine works very reliable with a standard Telco POTS line.

Who has a 'good' working solution to connect an ordinary Fax Machine to
Asterisk ?

Thanks for any help.
Alex

Parts of my setup:

Asterisk 1.2.1-BRIstuffed-0.3.0-PRE-1d built by root @ pbx on a i686 running 
Linux on 2006-01-05 13:25:25 UTC

# cat /etc/zaptel.conf
loadzone=be
defaultzone=be
span=1,1,3,ccs,ami
bchan=1-2
dchan=3
span=2,1,3,ccs,ami
bchan=4-5
dchan=6
span=3,1,3,ccs,ami
bchan=7-8
dchan=9
span=4,1,3,ccs,ami
bchan=10-11
dchan= 12
# TDM400P
fxoks=13-16

# cat /proc/zaptel/5
Span 5: WCTDM/0 "Wildcard TDM400P REV I Board 1"

          13 WCTDM/0/0 FXOKS (In use)
          14 WCTDM/0/1 FXOKS (In use)
          15 WCTDM/0/2 FXOKS (In use)
          16 WCTDM/0/3 FXOKS (In use)

Part of /etc/asterisk/zapata.conf:

[channels]
; Default language
language=be
callerid=asreceived
immediate=no
switchtype=euroisdn

<cut the ISDN (bristuff) part of it..>

;
; TDM40B kanalen
;
signalling=fxo_ks
language=be
context=analog
echocancel=no
channel => 13

signalling=fxo_ks
language=be
context=analog
echocancel=no
channel => 14

signalling=fxo_ks
language=be
context=analog
echocancel=no
channel => 15

signalling=fxo_ks
language=be
context=analog
echocancel=no
channel => 16


# Part of extensions.conf
; filter de Fax
exten => 15504409,1,Dial(Zap/13,60)
exten => 15504409,2,Hangup

Alex Ongena wrote:
> I have a running asterisk 1.2.1 (bristuffed) with a TDM400 Board. Connected
> to 1 port is am ordanary Fax Machine. Everything 'seems' to work,
> however receiving faxes is very unreliable.
http://www.digium.com/index.php?menu=product_detail&category=hardware&product=TDM400P&tab=support
(see the last list item) in other words: it often does not work.

regards
  frank