Tvark is a network monitoring tool (sniffer) with a GUI front end and
is tied to a MySQL database.  The GUI provides a view of traffic
activity that can be seen from the machine/interface that Tvark is run
on.  What you see is a list of source nodes on the left, destination
nodes on the right, and lines drawn, left to right, showing traffic
flow.  Tvark runs in "realtime", meaning you see the traffic roughly
as it happens.  There is a small delay between actual traffic flow and
the display because buffering of traffic information was necessary to
be able to determine rate information.  The color of the nodes, and
the lines between them, provide an indication of rate of traffic.

WWW: http://www.tvark.com/