Hi all There is some strange issue with t38-passthru (FreeSWITCH Version 1.2.0-rc2). Task - t38-passthru spa112(ip 1.1.1.1) <--(profile local)--> FreeSWITCH(ip 2.2.2.2)<--(profile extrernal)--> Mediant 2000(ip 3.3.3.3); fax from spa112 to Mediant 2000. In both profiles: <param name="t38-passthru" value="true"/> <param name="inbound-proxy-media" value="true"/> <param name="inbound-late-negotiation" value="true"/> Here is the sip-trace of the call with fax - http://pastebin.freeswitch.org/19866 It is seen that t38 re-INVITE from spa112 (profile local) passed on and back with "200 OK", but t38 from Mediant 2000 (profile external) is not (in response to re-INVITE t38 (SDP, m=image) - "200 OK" with SDP m=audio). After agreement the SDP, the data (v21-preamble) is not passed by freeswitch between spa112 and Mediant 2000, and one of the party ends conversation with message "no-signal" and then "by" . Wiki says ( http://wiki.freeswitch.org/wiki/Proxy_Media#Why_you_almost_certainly_don.27t... ) that module mod_spandsp is required (if I understand correctly), but "load mod_spandsp" does not change anything. I would appreciate your help -- Regards royj