Here are directions for using both Wireshark and Win Performance Monitor:
http://wpilib.screenstepslive.com/s/...andwidth-usage
I'd suggest shooting for max bandwidth in the pit or at home of under 5 or 4 Mbps (my team shoots for under 2Mbps to give them the option of adding a third camera should they ever feel it's necessary.
On the playing field the measured bandwidth regularly jumps 2 Mbps or so during matches depending on what the camera happens to be pointed at.
Always ask the field staff to help you monitor the real field conditions - drive teams have other things to watch during a match...
Get everything operating in that range and you can always increase it later on the real playing field when you see what the real performance turns out to be.