Hi Blair,
I think this depends on what you're trying to do - if you're trying to take
some measurements in order to take a baseline, the easiest way would be to
use the Room Console, connected to the room in question as it's used. The
"logs" panel will tell you the bandwidth usage for one particular user. This
is a tool used for estimating what usage looks like under different usage
scenarios.
Is this what you're looking for?
nigel