@kravietz @kensanata @grimmware @rysiek I have faxed over PSTN as well as over SIP in serial w/PSTN. You seem to be talking about quality not reliability. I use this cmd to obtain a WYSIWYG fax doc: gs -q -dNOPAUSE -dBATCH -sDEVICE=tiffg3 -r204x196 -sPAPERSIZE="$paperform" -dFIXEDMEDIA -sOutputFile="$tiffg3_filename" "$src_pdf"