[asterisk-users] Fax, T38 and NAT

[Johann Steinwendtner]

Magnus Benngård wrote:
> Gentlemen,
> 
> I have 3 faxes attached to an Asterisk. Fax - SPA2102 - Asterisk.
> 
> 0851711201 and 0851711290 is on our WAN, no NAT.
> 0197673581 is outside our WAN and needs to be NAT'ed.
> 
> Sending a fax from 0851711201 to 0851711290, no problem, switches to T38 
> and fax goes through.
> Sending a from 0197673581 to 0851711201, no problem as long as i dont 
> enable T38 on 0197673581.
> 
> But, if i enable T38 on 0197673581, changing t38pt_udptl=no to 
> t38pt_udptl=yes,fec and try to send from 0197673581 to 0851711201, it is 
> not working, switches to T38 sendimg a lot of UDPTL packages but it 
> looks like (at least for me) that addresses are "wrong".
> 
>  UDPTL (SIP/0197673581): packet from 90.230.92.67:33408 (type 0, seq 0, 
> len 6)
>  UDPTL (SIP/0851711201): packet from 10.242.20.149:16434 (type 0, seq 0, 
> len 6)
>  UDPTL (SIP/0197673581): packet from 90.230.92.67:33408 (type 0, seq 0, 
> len 6)
>  UDPTL (SIP/0851711201): packet from 10.242.20.149:16434 (type 0, seq 0, 
> len 6)
> 
> 90.230.92.67 is WAN ip of 0197673581's router.
> 10.242.20.149 is ip of 0851711201's ATA (SPA2102).
> 
> Shouldn't the UDPTL stream go through Asterisk?
> Have i missed sometheng else?
> 
> Asterisk SVN-trunk-r247652M built by root @ sip on a i686 running Linux 
> on 2010-01-25 11:10:15 UTC
> 
> [0197673581]
> secret=xyz
> callerid=Input Interior Orebro (fax) <0197673581>
> disallow=all
> allow=alaw:40
> allowoverlap=yes
> allowsubscribe=yes
> callcounter=yes
> callingpres=allowed_passed_screen
> canreinvite=no
> context=inputinterior.se
> directmedia=no
> dtmfmode=rfc2833
> faxdetect=no
> host=dynamic
> language=se
> nat=yes
> qualify=yes
> sendrpid=pai
> t38pt_udptl=no
> transport=udp
> trustrpid=yes
> type=friend
> videosupport=no
> 
> [0851711201]
> secret=xyz
> callerid=Input Interior Stockholm (fax) <0851711201>
> disallow=all
> allow=alaw:40
> allowoverlap=yes
> allowsubscribe=yes
> callcounter=yes
> callingpres=allowed_passed_screen
> canreinvite=yes
> context=inputinterior.se
> directmedia=yes
> dtmfmode=rfc2833
> faxdetect=no
> host=dynamic
> language=se
> nat=no
> qualify=yes
> sendrpid=pai
> t38pt_udptl=yes,fec
> transport=udp
> trustrpid=yes
> type=friend
> videosupport=no
> 
> [0851711290]
> secret=xyz
> callerid=Input Interior Sundbyberg (fax) <0851711290>
> ...
> rest is the same as [0851711201]
> 
> Regards,
> 
> Magnus
> 

Maybe you should give t38pt_usertpsource=yes a try.

Regards

Hans