I don't know about fedora but ubuntu guys have documentation (It mentions Reliance)
help.ubuntu.com/community/DialupModemHowto/LXU800
it says, it doesnt work out of the box, but you can see your device in "lsusb" (Can you?)
run following command on standard ubuntu (Try it on your distro with appropriate permissions)
modprobe usbserial vendor=0xeab product=0x9357
The device is detected. It shows up as three tty devices
ls -la /dev/ttyU*
Wvdial and its graphical frontend gnome-ppp if you found your modem.
Revant