Is it possible to network 3 to 5 computers (or more) if they were across the city? I don't know the exact terms but let's say I want to get a file from my friend who also has a cable modem, I could click on Network Neighborhood and see his computer there. I know there would have to be safety features added. Or this can't be done because of the swithers and routers Comcast uses? Is there any other way to have this done?