Hi All I have several problem after upgrading legacy system based on FreeSWITCH 1.2x to latest HEAD With no configuration changes and on the same hardware fax transmission success rate fall from 86% to 3% Most calls end up with SpanDSP status/error code 41 Dialplan part I'm using is: <extension name="infax_t38"> <condition field="destination_number" expression="^fax_(.*)$"/> <condition field="${acl(${network_addr} inbound_acl)}" expression="true"> <action application="export" data="nolocal:absolute_codec_string=PCMA,PCMU"/> <action application="set" data="api_hangup_hook=lua /usr/local/FreeswitchFax/rxfax_db.lua ${destination_number} ${uuid}"/> <action application="set" data="fax_ident=${destination_number:4:20}"/> <action application="set" data="fax_header=VirtualFAX"/> <action application="answer"/> <action application="playback" data="silence_stream://2000"/> <action application="set" data="fax_enable_t38=true"/> <action application="set" data="fax_use_ecm=true"/> <action application="set" data="fax_enable_t38_request=true"/> <action application="rxfax" data="/usr/local/freeswitch/var/rxfax/rxfax.${destination_number:4:20}.${uuid}.tiff"/> <action application="hangup"/> </condition> </extension> Any hints on what could cause such dramatic success rate?