[asterisk-users] Incoming Fax Issue with Asterisk 11.7 and Digium Fax

Jakob-Matthias Böttger jakob at j-mb.de
Mon Feb 3 06:20:58 CST 2014

Am 03.02.2014 12:56, schrieb Larry Moore:
> On 3/02/2014 7:38 PM, Jakob-Matthias Böttger wrote:
>> as He is describing it he should actually provide t.38. but i don't know
>> why it is not working thus im now getting
>> Feb 3 12:32:55] WARNING[9942][C-00000004]: chan_sip.c:10353 process_sdp:
>> Failed to initialize UDPTL, declining image stream
>> [Feb 3 12:32:55] WARNING[9942][C-00000004]: chan_sip.c:10497
>> process_sdp: Insufficient information in SDP (c=)...
>> and then the fax session starts recording data
> In udptl.conf set use_even_ports=yes and then issue a reload.
> You can confirm the settings have been applied by performing udptl 
> show config.
> Change the the t38 line to read as;
> t38pt_udptl=yes,redundancy,maxdatagram=400
> Reload sip and test.
after that i started udptl debug as well and now i'm getting lots of

UDPTL (SIP/sipcall.ch-00000007): packet to (seq 
152, len 11)

and in between

[Feb  3 13:18:30] WARNING[26313][C-00000007]: res_rtp_asterisk.c:3548 
ast_rtp_read: RTP Read too short

and in the end

[Feb  3 13:18:37] WARNING[9942]: chan_sip.c:4409 __sip_autodestruct: 
Autodestruct on dialog '24d15e0d-28df847a-9fae13c-7ace at sip.iforb.com~1o' 
with owner SIP/sipcall.ch-00000007 in place (Method: BYE). Rescheduling 
destruction for 10000 ms
[Feb  3 13:18:41] ERROR[26313][C-00000007]: res_fax.c:1535 
generic_fax_exec: channel 'SIP/sipcall.ch-00000007' FAX session '7' 
failure, reason: 'fax session timed-out' (TIMEOUT)
   == Spawn extension (fax-rx, receive, 11) exited non-zero on 

Thx, Jakob

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