Hi all, I've compiled freeswitch from git, configured an external trunk and added enabled-t38=true in fax.conf. Both servers have a public ip. Tring to send a fax from cli via origiante all t.38 fax fail with 2010-10-05 19:48:14.228734 [NOTICE] mod_sofia.c:880 Hangup sofia/external/xxxxxx@ip [CS_EXECUTE] [RECOVERY_ON_TIMER_EXPIRE] ... 2010-10-05 19:48:14.228734 [DEBUG] mod_spandsp_fax.c:335 Fax processing not successful - result (49) The call dropped prematurely. Reading documentation i've found that RECOVERY_ON_TIMER_EXPIRE can be caused by nat configuration problem, but i think configuration could be reasonably correct. sip flow: http://i56.tinypic.com/30j1ezn.png remote trying after the initial invite of fs: http://i52.tinypic.com/255hlps.png remote 183 session in progress: http://i54.tinypic.com/293jew2.png After 183 fs wait some time, probably a timeout, and send a cancel request. On fs cli i see also the data below, but fs never send to remote trunk. 2010-10-05 19:48:04.235005 [DEBUG] sofia_glue.c:137 sofia/external/xxxx@ip image media sdp: v=0 o=FreeSWITCH 1286300921 1286300923 IN IP4 213.187.9.30 s=FreeSWITCH c=IN IP4 xxx.xxx.9.30 t=0 0 m=image 21562 udptl t38 a=T38FaxVersion:0 a=T38MaxBitRate:14400 a=T38FaxFillBitRemoval a=T38FaxRateManagement:transferredTCF a=T38FaxMaxBuffer:2000 a=T38FaxMaxDatagram:400 a=T38FaxUdpEC:t38UDPRedundancy Can anyone give me a hint, if i'm wrong something? Many thx, Ale