[K12OSN] ltsp ethernet bandwidth monitor?

[light being]

Since LTSP is so bandwidth-intensive, Id like to do some tests with the 
bandwidth, as well as monitor it occasionally.

What are the programs I need to do those?  Ethereal?  Anything friendlier?

I have no idea how much is being used when, in reality.

How many terminals can a single server's ethernet manage at 100Mbits/s ?

The biggest enemy seems to be Flash.