My house was built around 2005, though I've only owned it a year. Setting aside from the insane cluster of coax wiring we found in the attic, I'm trying to understand why every room in the house has at least one, and usually two outlets that look like the attached pictures - two coax connectors, and two RJ11 cables connected to a single splitter. As I'm trying to figure out how best to get wired ethernet to various parts of the house, can anyone help me understand the purpose of this setup? Is it as simple as wanting the ability to put a TV and phone on every wall in the house? It doesn't seem like a pro did the work, especially considering the rats nest of coax in the attic.
Most likely this was a satellite dish hookup.
Back in the 90s, when the technology was nascent, each box got its own LNB feed from the dish. You'd also need an antenna hookup to get local broadcasts (as in two separate cable feeds). The phone line was so the satellite box could phone the company and report whatever purchases were made via the remote (like pay per view)
It doesn't seem like a pro did the work, especially considering the rats nest of coax in the attic.
In the earliest days you didn't have a whole cottage industry of professional installers like today. Instead, you had a lot of installers who doubled as local sales associates and it was merely a side business for them. My parents had one installed in their rural house in the mid 90s by a man from a nearby town who ran a hardware store. As such, you'd have some strange things done by installers (like using a phone duplexer to join lines).
Most modern installers don't even bother with your attic nowadays. They run it around the eaves of your house, then drop it down and straight through the outer and inner walls.
I'm curious if those are all bundled together into one cable in the wall? I have used cable that contained all 4 in one to simplify running it.
Notice that the two coax are different colors so the person wanted to be able to tell the difference between them. To me this implies a separate CATV and Satellite line, but it also could be cable internet or security cameras or many things. The blue cables appear to be cat5, but with only the center pair of each being used. This might have been done if one served landline phone and the other served something like a voip bridge like Magic Jack. They're in the splitter so that one will serve as "Line 1" and the other as "Line 2" to typical multi-line telephones.
If your goal is cable and Ethernet to each room I think you're in great shape! You need to find out where the Ethernet goes and hope they all go to one place instead if being bonded up in the attic.
There might be many answers to this but as someone that had both satellite and cable tv in the past this could be the reason for 2 coax drops in each rooms. For the modular connection that looks like someone used a cat 5? Cable for phone. Using the 2-1 device ties the cables together and not all the conductors are used so that was possibly their way of doing the phones without patch panels or punch down blocks. I have not seen that method used since cat 3 days. There could be other reasons but I have seen and wired dual coax drops but not the phone / data like that unless only phone.
I had a similar system wired in my house. They ran a 6 pair cable to every room in the house and connected them all together in a junction box with a 6 pair to the Bell pedestal.
They also ran two coax to each room. One set was run outdoors for CATV and the other set was hooked up to an indoor antenna located in the attic for local TV. I've actually kept that hooked up because that way, when we lose cable, I still have the locals.
A two into one is for either for data line and phone, which is the most likely reason. While the input is two sets of four wires, only two in each set is active. The single R11 plug will provide phone connect to the phone and the other pair provides data connection to the data line. The data line was a voice line dedicated to a modem for people who needed data connective for a long period of time. Using the modem prevented incoming calls and also prevented you from making a call, so two lines were required.
The same setup is sometimes used to connect two phone lines to one outlet. A two line phones is plug in, and the phone can connect or answer calls coming into either phone.
The third use for this type of connection was for two phone lines, one for voice, and the other was a fax machine. Older phones were POTS (Plain Old Telephone System) with no intelligence, same as the fax machine. None of these after 4 rings, the fax machine would pick up the call.
For installing wired ethernet into every room, you will need Cat-6 or Cat-6 POE or newer types of ethernet cables to support the bandwidth.
The existing wires cannot support this. You may be able to use the wires to provide a map of the path to use to route new wires or to assist in pulling the wires through existing holes through the header and on to the outlets in the wall.
It sure seems that they had DSL at some point. To run DSL you need a line for data and another for phone. Also depending on company (DSL setup) you cannot just "disconnect" (or cut) the phone line as the lines are looped at a point and the phone line is used to help meter (filter) the line to certain specs.
Cable TV was originally analog, often delivered over two co-ax cables because one cable didn't have the bandwidth for all the channels offered. Even today you'll often find dual co-ax still strung here and there where no one has bothered to remove it. Until two years ago the cable TV wire attached to my house was dual, with one half just sort of hanging down in the weather.
A house built in 2005 might have been wired up by someone used to putting in dual co-ax, and nobody had gotten around to telling him about the digital age.