Haven't seen that one before, we use T.38 pass through over G711 and never had any problems that can't be explained, possibly an incompatible destination. I've found this, they're using mod_fax not mod_spandsp_fax but the error is similar might help point you in the right direction: http://lists.freeswitch.org/pipermail/freeswitch-users/2009-September/047151... Would be useful to see the logs for mod_spandsp_fax from the beginning, might be some hidden clues. Make sure you enable verbose in 'conf/autoload_configs/spandsp.conf.xml'. Shaun -----Original Message----- From: FreeSWITCH-users [mailto:freeswitch-users-bounces@lists.freeswitch.org] On Behalf Of António Silva Sent: 24 November 2017 17:53 To: freeswitch-users@lists.freeswitch.org Subject: [Freeswitch-users] txfax unexpected message received Hi, when sending a fax to a particular destination it fails with "Fax processing not successful - result (13) Unexpected message received." To other destination is working ok, i don't know what is the particularity on this one that makes it fail... From the logs i see: 2017-11-24 18:30:05.625309 [DEBUG] mod_spandsp_fax.c:276 FLOW T.30 Rx: CFR with final frame tag 2017-11-24 18:30:05.625309 [DEBUG] mod_spandsp_fax.c:276 FLOW T.30 Rx: ff 13 84 2017-11-24 18:30:05.625309 [DEBUG] mod_spandsp_fax.c:276 FLOW T.30 Rx final frame in state D 2017-11-24 18:30:05.625309 [DEBUG] mod_spandsp_fax.c:276 FLOW T.30 Unexpected CFR frame in state D I guess that is not suppose to receive confirmed to received.. because the training is not yet done. Can i do anything from my side to make it work? I've tried with different resolutions but no luck.. i try with t38 but this gw the t38 is not well implemented and also didn't work. To send the fax i just do: originate {fax_verbose=true}sofia/gateway/CS2K/939165135 &txfax(/root/txfax.tiff) Attach full log. Thanks for the help. -- Saludos / Regards / Cumprimentos António Silva ______________________________________________________________________ This message has been checked for all known viruses by MessageLabs Virus Scanning Service. ______________________________________________________________________ ______________________________________________________________________ This message has been checked for all known viruses by MessageLabs Virus Scanning Service. ______________________________________________________________________