vnstat | console-based network traffic monitor | Mehr ...
vnStat is a network traffic monitor for Linux. It keeps a log of daily network traffic for the selected interface(s). vnStat is not a packet sniffer. The traffic information is analyzed from the /proc filesystem, so vnStat can be used without root permissions.
vnstati | image output support for vnStat | Mehr ...
vnStati provides image output support for statistics collected using vnStat. The image file format is limited to png. All basic outputs of vnStat are supported excluding live traffic features. The image can be outputted either to a file or to standard output.