I mentioned in my last post that I still needed to use Verizon's ActionTec router. The reason for this is actually rather stupid.
But first, a small digression about it. Most people have their system set up so that that router gets all of its input from its coax connection. (The reason for this is that it spares them from having to run another cable to the router. If you're using existing cable TV wiring, this is a good reason. But it limits your options; you MUST use this router to connect FiOS, if you don't run that extra cable. This will detail why that might not be such a good idea (like most things related to the network, it depends on your needs).)
Ok, so you have your router plugged directly into the ethernet port on the ONT; why do you still need their router connected? Well, because the set-top boxes for your TVs need it for the guide, VOD, and similar stuff. How do they use it? They use it as a MoCA (Media over Coaxial cable Alliance) bridge to access the internet.
This seems like a pretty cool thing. Now you only need to run a coax cable (which you've already done) to each TV to get that stuff.
So why did I say that it's pretty stupid? Because the STB already has an ethernet port. And it won't use it. So, even if you've got that cat5 cable run, you still need that router to act as the bridge. And that just blows.