[asterisk-users] Asterisk 13, PJSIP and T38 problem

[Marco Capetta]

Hello,

I need help to solve a problem that I am having using Asterisk 13, PJSIP and T38.

My setup is as follows:
SIP Provider --> Asterisk 13 --> Patton --> Physical Fax
I need to get the fax directly in T38 to Patton.

The provider sends me the fax in T38.
If I receive the T38 fax on Asterisk (using an hylafax device), I can properly receive the fax.
If I send a T38 fax with Asterisk (using an hylafax device) directly to the Patton, I receive it correctly on the physical fax.

Instead, if I route, through Asterisk, the t38 fax call received by the provider to the Patton, I can not receive anything.
From UDPTL debug I can see the flow of some udptl packages from the provider to Asterisk, but I see no udptl package from Asterisk to the Patton.
From PJSIP logs, it seems that the T38 is properly negotiated by both parties.
From the debug of the Patton i see many "Wrong media type. Drop FAX Packet”.

How to ensure that the fax, received by asterisk from the provider with T38 protocol, is routed to the Patton using again T38 protocol?

Below my pjsip.conf” file:


;===============TRANSPORT=========================

[simpletrans]
type=transport
protocol=udp
bind=0.0.0.0:5060


;===============TRUNK==============================

[trunk-provider]
type=endpoint
transport=simpletrans
context=in_provider
direct_media=no
disallow=all
allow=alaw
allow=g729
aors=trunk-provider
t38_udptl=yes
t38_udptl_ec=redundancy
t38_udptl_maxdatagram=400

[trunk-provider]
type=aor
contact=sip:X.X.X.X:5060

[trunk-provider]
type=identify
endpoint=trunk-provider
match=X.X.X.X
match=X.X.X.X



[trunk-patton]
type=aor
max_contacts=5

[trunk-patton]
type=endpoint
transport=simpletrans
context=in_patton
direct_media=no
disallow=all
allow=alaw
auth=trunk-patton
aors=trunk-patton
t38_udptl=yes
t38_udptl_ec=fec
t38_udptl_maxdatagram=400

[trunk-patton]
type=auth
auth_type=userpass
password=XXXXX
username=XXXXX

=============================================

Thanks
Marco