[asterisk-users] Asterisk T.38 Pass-Through doesn't work

[Андрей Половов]

What I have is:
* Asterisk 1.8.10.1~dfsg-1ubuntu1,
* SPA112 ATA with analog fax in 1-st FXS port connected,
* SIP trunk with provider supporting T.38.

My network looks like this:
* spa112 (192.168.33.200/24) and Asterisk (192.168.5.253/24) in 
neighbouring LANs,
* Asterisk connects to the provider (80.75.130.136) via router 
(82.200.7.184). Router has full DNAT to Asterisk server.

What happens?
* The fax from SPA112 to Asterisk cmd ReceiveFax works well,
* The fax from Asterisk cmd SendFax to PSTN fax works well,
* However, the fax from SPA112 to PSTN fax doesn't work. Using udptl 
debug, I can see packets between Asterisk and both sides (SPA112 and 
PSTN fax) but it seems that faxes can't agree how to send image.

== sip.conf:
[general]
tcpenable=yes
videosupport=yes
transport=udp,tcp
dtmfmode=rfc2833
qualify=yes
directmedia=no
allowguest=no
alwaysauthreject=yes
rtcachefriends=yes
rtupdate=no
callcounter=yes
t38pt_udptl=yes,redundancy,maxdatagram=200
t38pt_rtp=no
t38pt_tcp=no
ignoresdpversion=yes
disallow=all
allow=alaw
allow=ulaw
externip=82.200.7.184
localnet=192.168.0.0/255.255.0.0

[mtt]
type=peer
host=80.75.130.136
fromuser=74957777777
disallow=all
allow=alaw,ulaw
directmedia=no
canreinvite=no
nat=yes

== udptl.conf:
[general]
udptlstart=4000
udptlend=4999
T38FaxUdpEC=t38UDPRedundancy
T38FaxMaxDatagram=200
udptlfecentries = 3
udptlfecspan = 3
use_even_ports = no

== spa112 SIP settings screenshot:
http://tinypic.com/view.php?pic=2z8dic6&s=5

== debug log:
https://gist.github.com/anonymous/5685307

Please, help me!