Under Network Settings:
- Create a Captive Portal (named, e.g., “ConstrainedAccess”). For access control you have a number of options, one being “Guest Account” (others might be applicable as well, e.g. “Token”).
- After enabling “Guest Account” save the configuration, then return to it and under “Guest Account” click on “Manage”. Then define the user accounts (which may be managed right there or imported from a CSV file) and set the usage quota and the reset interval (in your case every 1 days).
- Create the VLAN for constrained-usage connections (named, e.g., “Constrained”). Select “ConstrainedAccess” as the associated captive portal.
You can work with a variety of access controls (e.g., MAC addresses) besides the guest login option.
FWIW: From my limited experience with the “Guest Account” constraint it seems that the enforcement of the constraint (e.g., 5GB/day) is a bit sloppy (i.e., the user may run over before being stopped).
My experience with the portal mechanism generally is not extensive (primarily employing the “Token” access control mechanism), so wiser heads may want to improve or propose alternative strategies.