nload

Select the interfaces you want to watch and use nload’s separate incoming and outgoing graphs with minimum, maximum and total figures. Arrow keys switch devices; the multiple-device mode shows several together but omits the graphs. Units, average window and display interval are adjustable, and the supplied manual documents appending traffic samples to a text table. Avoid treating a faster refresh as more accurate: it warns that intervals shorter than about 100 milliseconds make calculations imprecise. nload is GPL-licensed source software. Its interface view helps confirm a sustained upload or download, while identifying the application responsible requires process attribution elsewhere.