Top like Utility to monitor Network Connections usage - pktstat

pktstat displays a real-time list of active connections seen on a network interface, and how much bandwidth is being used by what.

It partially decodes HTTP and FTP protocols to show what filename is being transferred, as well as X11 application names. Entries hang around on the screen for a few seconds so you can see what just happened, in short a very useful tool to figure out network connection in real time.

Pktstat Installation:
Open up the terminal Application > Accessories > Terminal and type following command to install pktstat:

sudo apt-get install pktstat

Pktstat is an command line tool, after successful installation you can type command "pktstat" to start monitoring your network connection ...