[asterisk-users] Problems with rxfax

Mon Jan 22 02:11:31 MST 2007

Dear list,

The company I'm working for is trying to use app_rxfax to receive faxes
on an Asterisk machine. Our initial tests looked very promising, but
unfortunately we've encountered some problems. We've been trying to
solve these problems for quite some time now, but we're running out of
options. So I really hope that somebody can give some help here.
Basically our set-up is this: We have an Asterisk server (version 1.2.7)
with an ISDN trunk (Sangoma A104D), we've configured asterisk to run
rxfax on a specified extension. Originally we started out with spandsp
0.0.2pre26 and the original app_rxfax for spandsp 0.0.2. Some of the
faxes were coming in perfectly, but soon we noticed that quite often
there were substantial pieces of the fax missing in the resulting tif
file. 
We've tried the following to solve these problems:

- We've checked the timing settings for the ISDN trunk, these seem to be
ok.
- We've tried several versions of libtiff (currently we are using
3.7.2).
- We've tried using 0.0.3 versions of spandsp (since we're using
asterisk 1.2.7 we had to modify app_rxfax.c to work).
- We've created a custom dialplan application to disable the echo
cancellation on the isdn channel on which the fax is received.
- We've tried various settings for t30_set_supported_compressions,
t30_set_supported_image_sizes, t30_set_supported_modems and
t30_set_supported_resolutions (I must confes that I didn't really know
which settings to use here, but we have tried a lot of them).
- We've tried several fax machines to send the faxes, ranging from
simple fax-modems to large dedicated fax machines.

But still a lot of faxes give problems, either the tif is missing large
portions, or the fax isn't received at all. At the bottom of this mail
are 2 examples of the logging when it goes wrong. I really hope that
somebody can give a few pointers. Thanks in advance,

Kind regards,
Ardjan Zwartjes,
Telecats

======= Example 1 =========================

Jan 19 14:49:14 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 0
Jan 19 14:49:14 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 4
Jan 19 14:49:17 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 4
Jan 19 14:49:17 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 0
Jan 19 14:49:19 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 8
Jan 19 14:49:19 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 0
Jan 19 14:49:20 DEBUG[24218] app_rxfax.c: FLOW FAX Switching from V.29 +
V.21 to V.29 (-22.18dBm0)
Jan 19 14:49:21 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 0
Jan 19 14:49:21 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 4
Jan 19 14:49:23 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 8
Jan 19 14:49:23 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 0
Jan 19 14:49:23 DEBUG[24218] app_rxfax.c: FLOW FAX Switching from V.29 +
V.21 to V.29 (-17.84dBm0)
Jan 19 14:49:38 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 4
Jan 19 14:49:38 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 0
Jan 19 14:49:39 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 0
Jan 19 14:49:39 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 4
Jan 19 14:49:41 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 8
Jan 19 14:49:41 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 0
Jan 19 14:49:42 DEBUG[24218] app_rxfax.c: FLOW FAX Switching from V.29 +
V.21 to V.29 (-19.13dBm0)
Jan 19 14:49:48 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 4
Jan 19 14:49:48 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 0
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c:
========================================================================
======
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: Pages transferred:  1
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: Image size:         1728 x
1192
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: Image resolution    8037 x
7700
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: Transfer Rate:      9600
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: Bad rows            0
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: Longest bad row run 0
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: Compression type    3
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: Image size (bytes)  0
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c:
========================================================================
======
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 0
Jan 19 14:49:49 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 4
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 0
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 1
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c:
========================================================================
======
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: Fax successfully received.
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: Remote station id: 
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: Local station id:  "Test Fax"
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: Pages transferred: 1
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: Image resolution:  8037 x 7700
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: Transfer Rate:     9600
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c:
========================================================================
======
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: FLOW FAX Set rx type 13
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: FLOW FAX FAX exchange complete
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: FLOW FAX Set tx type 13
Jan 19 14:49:51 DEBUG[24218] app_rxfax.c: FLOW FAX FAX exchange complete
Jan 19 14:49:53 DEBUG[24218] app_rxfax.c: Got hangup

=========Example 2==================
Jan 18 09:56:12 VERBOSE[4185] logger.c:     -- Executing
RxFAX("Zap/31-1", "/tmp/1169110572.239.tif|debug") in new stack
Jan 18 09:56:15 DEBUG[4185] app_rxfax.c: FLOW FAX Set rx type 0
Jan 18 09:56:15 DEBUG[4185] app_rxfax.c: FLOW FAX Set tx type 4
Jan 18 09:56:17 DEBUG[4185] app_rxfax.c: FLOW FAX Set rx type 4
Jan 18 09:56:17 DEBUG[4185] app_rxfax.c: FLOW FAX Set tx type 0
Jan 18 09:56:19 DEBUG[4185] app_rxfax.c: FLOW FAX Set rx type 8
Jan 18 09:56:19 DEBUG[4185] app_rxfax.c: FLOW FAX Set tx type 0
Jan 18 09:56:26 DEBUG[4185] app_rxfax.c: FLOW FAX Set rx type 0
Jan 18 09:56:26 DEBUG[4185] app_rxfax.c: FLOW FAX Set tx type 4
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c: FLOW FAX Set rx type 0
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c: FLOW FAX Set tx type 1
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c:
========================================================================
======
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c: Fax receive not successful -
result (31) Carrier lost during fax receive.
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c:
========================================================================
======
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c: FLOW FAX Set rx type 13
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c: FLOW FAX FAX exchange complete
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c: FLOW FAX Set tx type 13
Jan 18 09:56:27 DEBUG[4185] app_rxfax.c: FLOW FAX FAX exchange complete
Jan 18 09:56:39 DEBUG[4185] app_rxfax.c: Got hangup

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