Asterisk 1.6.x t38 passthru

Asterisk Asterisk Support
1

Hi,
I’ve encountered a problem with t38 passthru on asterisk 1.6.x.
I’m trying to send fax from VoIP operator (one peer) to another peer (fax software - Commetrex). On Asterisk 1.4 it works perfectly, however in 1.6 the t38 is negotiated (re-invite), but the training of t38 is not finished.
(messages CSI Num, DIS DSR, no-signal, and cng are flowing, however there is no training).

Part of my sip.conf
t38pt_udptl = yes
t38pt_rtp=no
t38pt_tcp=no

the definition of my peer:

[fax]
type=peer
username=fax
secret=fax
fromusername=fax
fromdomain=127.0.0.1
context=xxx
host=127.0.0.1
port=5080
insecure=invite,port
qualify=yes

Any help would be really appreciated.

2

maybe the problem is with the loopback interface?
I’ve changed the commetrex settings to send onlu ulaw and i’ve got ICMP destination unreachable packets on my loopback interface. The ICMP packets concerned the asterisk RTP port.

3

Has anyone successfully run asterisk 1.6.x with t38 passthru (negotiated by re-invite) ?

4

I have the same problem…

my architecture is:

T38gateway–SER–ASTERISK–SER–ClientFAX

I can call the T38gateway. my fax receive the ringing and 200OK.
but nothing after, no RTP…

why?

5

fax-asterisk-T38gateway

fax->asterisk invite(g711)
asterisk->fax ringing,200OK…
fax->asterisk invite(T38)
asterisk->fax trying (asterisk accept the T38)
asterisk->asterisk invite(T38), then problem in the SDP…

is it normal that asterisk use the loopback?