This wiki is a community-maintained resource about everything there is to know about IPFire.
Iftop display bandwidth usage on an interface.
You can install iftop with Pakfire or by using the shell with:
pakfire install -y iftop
To start the service just type into your shell:
or to monitor for specific interface:
iftop -i green0
type 'h' to display complete help
You can get more information Here