Short answer - if you're using a router to share the connection there is no easy way to do this. All client side applications will only monitor badwidth running on the client (your computer)
/edit also high pings in BF2 have little to do with your bandwidth, ping is the amount of time it takes for one packet to go from your computer to another computer, and is impacted by distance to the server, the number of hops, and even the transport medium.