I had this explained to me, badly, by a Coral Cable engineer. Apparently their signal even when working properly direct from their modem may still not work properly if routed through another device, such as a wireless router. It wasn't fully explained and I don't understand it, but apparently it's the reason several people recently lost their internet. Even though the router was fully functioning and undamaged it wouldn't work on their system. Perhaps someone else can explain what's going on.