I have problem with USR Robotics conected to an INDY, when i configure it like a FAX Class 2.0, In the xferlog it says:
Unable to set session parameters
You need patch 766 or similar. Once this is installed be certain ClocalAsRoot is set to yes in your modem config file. This is described in the HTML documentation in the section on setting up a server.
Beware that the error may be caused by many things. One potential common problem is if a server is setup as a send-only system (i.e. no faxgetty) and the modem is incapable of sending 2D-encoded data. Then if a 2D-encoded fax is submitted by faxq the faxsend program may/will get an error when it tries to setup the session parameters resulting in this error--very different from problem originally described.