Focus mode

The Control Center shows the network traffic of the last five minutes at a glance. When you notice a peak in the traffic chart, focus mode lets you focus on that particular part of the traffic to figure out which process caused it. It places a frame on the chart, and the list below the chart shows only the processes with traffic in that time interval.

Move the pointer over the focus icon at the top right of the traffic chart. A frame appears on the chart.
Move the frame over the part of the chart that interests you. The list shows the processes with traffic in that interval.
To analyze the interval in detail, click it. Network Monitor opens with a time filter for that interval.

By default, the frame is 30 seconds wide. Modifier keys give you a shortcut and a wider frame: hold them down while you move the pointer over the chart, and the frame appears right away, without the focus icon. The keys decide how wide it is:

Command 30 seconds, as with the focus icon.
Option 50 seconds.
Option-Command the full five minutes.

Traffic volume and traffic rates

The figures inside the traffic chart show the total traffic volume of the last five minutes. In focus mode, while you point at the chart, they show the volume of the bars under the pointer.

Likewise, the traffic rates displayed above the chart refer to the focused time interval in focus mode. They are shown according to the Show traffic rates above chart setting in the Control Center settings.