I don't get cable/coax networking protocols.

I’m having problems getting a clean Comcast signal to one room in my house. Used to work fine but at about the time of the digital transition, the signal started to fail. Comcast can see and query the cablecard but we can’t get any channel signals through. All the coax and cat5 cabling in our house goes back to a central wiring closet; the ethernet network in the room in question works fine at 1 gigabit but for some reason the coax/cable network fails.

Why does the protocol/modulation scheme for cable fail? Why can the device be addressed and queried but we can’t see channels? Why do they need to put a signal amplifier on the line – i never need to do this for ethernet? Is comcast still using some analog scheme to send the signals across? This just seems odd and ridiculously archaic. And the crazy pairing nonsense for cablecards with all kinds of identifiers needed to be traded back and forth – it makes DHCP and mac addresses look positively simple.

I know I could go read about 64QAM and 256QAM and Cablelabs and all kinds of other stuff to get all smartened up about this but I am frankly tired of dealing with it. I’ve been ignoring the verizon fios offering in our neighborhood but if it would let me junk the coax and move to all cat5/ip i might consider….