When I used to do work for towns and such that use TW in Rochester for their internet lines, sometimes a whole grid would go out. It could be anything from some dumbass construction crew hit a line to their DNS servers shit the bed. If you are plugged right into your modem and can pull IP addresses, try to change your DNS servers to some other free ones. Might not be 100% stable but can help you get by if its just the TW DNS system shitting the bed.