“NTM (Network Traffic Monitor) an open source network traffic
monitoring application for Linux-based operating systems, which
displays network bandwidth usage by integrating with the default
Network Monitor. It does not require root privileges to function,
and can be configured to disconnect when a user-defined threshold
is reached. NTM is useful for users who may have an internet
connection with bandwidth limit imposed by their ISP.By default, NTM uses ppp0 network interface which is used for
modems. However, if you wish to track your wireless traffic, use
wlan0. It provides you with the choice to monitor bandwidth usage
according to the required day, week, month or year, with
auto-update and auto-disconnection. Monitoring for speed and
sessions is also available.