Real-time bandwidth provides a live monitoring of all the interfaces available to the router. Most likely the most significant being the WAN interface (vlan2 in the great majority of the cases). Note data is reset when the page is first opened and will populate gradually. The maximum display window is 10 minutes and data resolution is 2 seconds. Max one interface at any given time can be displayed. Clicking on the interface name will switch view.
Avg. allows you to apply percentile display (cut spikes)
Max: Uniform scales all the interface charts to max data point recorded amongst all the interfaces. Per If scales based on data relevant to the individual interface only.
Unit: kbit/KB, Mbit/MB - toggles between 1,000 and 1,000,000 display units
Display: Solid = represent usage with an area, Line = represents usage with a single line related to max value only.
Color: Switch between different preselected color combinations.