first a little background: we are a small ISP and as such are providing networkinfrastructure and internetaccess to a multitude of users. Some of them use p2p networks which yields us lots of cease and desist orders. One location in particular stands out and produces one such order per week.
How would you go about the problem technically? How would you isolate and identify the users using p2p for illegal filesharing? Is it even possible to do this using routerOS solely? would you do it at all?