From time to time connection to my server is very slow. This could be that someone is doing large uploads or downloads. Since I have a lot of software on my server I would like to find out, which process is responsible for the traffic.
Is there a simple command which lists processes which are currently doing network communication, sorted by the amout of traffic that was created in the last x seconds?
My system is running Ubuntu.
You could use this post on AskUbuntu
This post explain installing and using iftop.
You can use something like nethogs (http://nethogs.sourceforge.net/) or iftop (http://www.thegeekstuff.com/2008/12/iftop-guide-display-network-interface-bandwidth-usage-on-linux/).