The Optical Network Terminal (ONT) is the last box in the chain before you get to your set-top box. The existing coaxial cable in the house should be connected to the ONT - which, of course, means that it will no longer be connected to the Comcast box, where ever that happens to be. The Verizon set-top box is then connected to the coaxial in the house, and then to the TV itself. If you have both FiOS TV and FiOS internet, then you'll need a cable splitter for the coaxial if the router and the set-top box are to be set up near each other. You attach the coaxial to the signal splitter, which will have two separate pieces of coax coming out of it, then attach one of those pieces to the set-top box and the other to the modem.
sort of like this:
If the router and set-top box are going to be set up in different locations, and you have pre-existing coax going to each location, then you wouldn't need a signal splitter (your existing wiring already has a splitter somewhere), in which case you would just plug the TV set-top box into the coax at the location where it'll go and the router into the coax at the location where it'll go.
All of my confusion comes from the fact that I have FIOS in my man cave.
The tech used an existing cable in the wall to my FIOS modem.
This was after he installed the ONT outside, battery backup for the phone and then went into the attic .. to do something?
Now, I don't know if I only have FIOS in that (man cave) room and all of the other in wall
cables can only run comcast?
I am running comcast tv right now from the rooms that I want to run FIOS tomorrow.
I just don't know if when I cancel comcast tomorrow and activate FIOS .. will it run over those existing cables without me having to do anything else.
Unplug comcast boxes .. plug in FIOS?