Device Data Usage feature shows internet usage data and allows putting limits on them per device. 

To enable this powerful feature simply enable the switch next to Collect Device Data Usage in Advanced Settings > Miscellaneous page. Then view the data usage for each device in the Usage > Device Data Usage page.

As this powerful feature causes about 10% degradation, it is by default disabled. We recommend disabling it, if your Roqos Core's forwarding rate is more important.