slightly modified by me.
Bmon is an interface bandwidth monitor. It is able to generate and
draw three types of diagrams: The overview diagram which is a list of
all interfaces and their send/receive rates. A very MRTG like
graphical diagram in ASCII showing the rate over a specific time
period in a bar diagram. The details diagram which contains all
counters of an interface such as total bytes sent/received, errors,
compressed packets and so on.