How to send and receive fax between two Asterisk 1.6.0.6

Hi everybody,
I’m trying to make Asterisk T.38 fax work.
I want to send .tif file from one Asterisk box (A) to another Asteriks box (B).
And if it happens, I move forward to working and testing Asterisk fax capabilities with my ATA equipment.

I have 2 Asterisk boxes:

Asterisk A:
Asterisk -1.6.0.6
spandsp-0.0.5_pre4
Linux 2.6.25-gentoo-r9 i686

Asterisk B:
Asterisk -1.6.0.6
spandsp-0.0.5_pre4
Linux 2.6.25-gentoo-r8 i686

and one xLite shoftphone.

I dial 333 from my xLite, this launches SendFax(/tmp/sendfax.tif) application on Asterisk A. And in the CLI I see the following:

== Using SIP RTP CoS mark 5 == Using UDPTL CoS mark 5 -- Executing [333@543:1] Dial("SIP/312-086054f0", "SIP/makak/999,120,M(sendfax)") in new stack == Using SIP RTP CoS mark 5 == Using UDPTL CoS mark 5 -- Called makak/999 -- SIP/makak-086094f0 answered SIP/312-086054f0 -- Executing [s@macro-sendfax:1] SendFAX("SIP/makak-086094f0", "/tmp/sendfax.tif") in new stack

So Asterisk A is trying to send fax to Asterisk B. At the same time in Asterisk B CLI I see the following:

== Using SIP RTP CoS mark 5 -- Executing [999@test:1] Set("SIP/312-0823f988", "FAXFILE=/tmp/asterisk/receivedfax.tif") in new stack -- Executing [999@test:2] ReceiveFAX("SIP/312-0823f988", "/tmp/asterisk/receivedfax.tif") in new stack
Thus, Asterisk A makes a channel to Asterisk B, and Asterisk A trying to send a fax to Asterisk B.

After 5 minutes in Asterisk A CLI I see:

[Mar 6 09:46:55] WARNING[15432]: app_fax.c:442 transmit_audio: It looks like we hung. Aborting. [Mar 6 09:46:55] WARNING[15432]: app_fax.c:176 phase_e_handler: Error transmitting fax. result=49: The call dropped prematurely. [Mar 6 09:46:55] WARNING[15432]: app_fax.c:621 transmit: Transmission error == Spawn extension (macro-sendfax, s, 1) exited non-zero on 'SIP/makak-086094f0' in macro 'sendfax' -- Packet2Packet bridging SIP/312-086054f0 and SIP/makak-086094f0 == Spawn extension (543, 333, 1) exited non-zero on 'SIP/312-086054f0'

in Asterisk B CLI I see:

[Mar 6 09:59:47] WARNING[4383]: app_fax.c:176 phase_e_handler: Error transmitting fax. result=48: Disconnected after permitted retries. [Mar 6 09:59:47] WARNING[4383]: app_fax.c:624 transmit: Transmission failed -- Executing [999@test:3] Hangup("SIP/312-0823f988", "") in new stack == Spawn extension (test, 999, 3) exited non-zero on 'SIP/312-0823f988'

Asterisk A sip.conf:
[size=75][general]
t38pt_udptl=yes
context=default
bindport=5060
bindaddr=0.0.0.0
tcpenable=no
tcpbindaddr=0.0.0.0
srvlookup=yes
register => cyberpunk:cyberpunkpass@192.168.250.6/makak

[authentication]

; Xlite phone
[312]
t38_udptl=yes
type=friend
host=dynamic
username=312
secret=312
nat=no
canreinvite=no
context=543
disallow=all
allow=alaw

; Asterisk B
[makak]
t38_udptl=yes
type=friend
secret=makakpass
context=makak_incoming
host=dynamic
nat=no
disallow=all
allow=alaw[/size]

Asterisk B sip.conf:
[size=75][general]
t38_udptl=yes
context=default
allowoverlap=no
bindport=5060
bindaddr=0.0.0.0
tcpenable=no
tcpbindaddr=0.0.0.0
srvlookup=yes

register => makak:makakpass@192.168.253.220/cyberpunk

[authentication]

; Asterisk A
[cyberpunk]
t38_udptl=yes
type=friend
secret=cyberpunkpass
context=cyberpunk_incoming
host=dynamic
nat=no
disallow=all
allow=alaw

; Xlite phone
[312]
t38_udptl=yes
type=friend
host=dynamic
nat=no
canreinvite=no
disallow=all
allow=alaw
context=test[/size]

What am I doing wrong? Is that possible to send fax from one asterisk to another the way I do? I’ll be pleased to read your hints and advices.