My son hasn't been able to get on live for 2 days now. Mine is fine. Microsoft says the router isn't 'routing'.
He wanted me to restart the router. No way dude. I'm not taking a chance on killing my live too. Plus, every computer on the router 'routes' just fine.
It's either he is connecting to a different Live server than I am, or his Xbox is dying...which could be. He had burned up 4 of those external Intercooler fans in less than 8 months.