I've recently moved house and signed-up to O2 Broadband. They've supplied an O2-branded wireless router that plugs straight into the phone line. This means my AirPort Extreme is now useless, but I'd like to use it. Do I have to use the O2 router, or could I go and buy a cheap wired router to plug in to my AirPort? I don't really understand why I can't just use my AirPort and bypass O2's router altogether. Any advice/explanation would be great!