first to note, fax/modem/whatever but human voice, connected to anything but FXS ports on the same router with POTS connections, is likely to give trouble.
Of course it is possible that your CC machine is so remote that the arrangement above is not possible.
This said, you should at the minimum specify which image type and version you have on the ATA, and if you have configured according to the guidelines for fax. The recommended image to do that, is H.323.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.