Data use monitor for single network adapter (WAN)
 

I've bought a laptop which has a WWAN card attached and I'm going to use a sim card with a very limited data plan so that I have an extra network to try when I'm out with clients. I figure this should reduce my chances of being unable to connect to anything.

I'm looking for a package which can monitor the data sent and received over the WAN card adapter only (no need to measure wifi and eth adapters), and preferably one which can warn/block when a limit is reached as the price per mb shoots up after the allowance is used on the contract.

My kung-fu is not strong but I'm not afraid of a terminal/script-based solution and I've seen a couple of options that might be made to serve, but I suspected someone somewhere will have already solved this with something more elegant. Any ideas?

The tool might help you, http://www.manageengine.com/network-...g&gclsrc=aw.ds