Yes, you can use zf7321 standalone firmware 100.1.0.0.432 to configure your AP as a Wireless router.
However, with only one Ethernet interface, which must be your WAN to the DSL modem, you will only
be able to connect to an Internal WLAN from wireless devices. You still need to define a Local Network,
and use NAT Route to WAN under your WLAN definition.
APs with two or more Ethernet ports, can connect a second one to a switch to allow LAN (wired) as well
as Wireless access.
https://support.ruckuswireless.com/software/838-standalone-ap-software-100-1-0-0-432-indoor-aps