I have a room (room A) with a wifi router setup, where there is an unused outlets with two vertical plug-in slots near it. My office (far from room A) has something similar (with 1 plug-in slot). I tried but the ethernet cable doesn't work. Can these be used to somehow connect my router internet to my computer in my office? If this is for TV or phone which I have no use, can I use the existing line to fishing through an ethernet cable so I can connect my computer in the office to the router physically?
These are phone wires. I would not bother trying to use them for ethernet. Even if the wires themselves are suitable for it, there are so many phone-wire installation practices that are incompatible with ethernet that I wouldn't count on their working properly. And "properly" is a big deal ... they may work poorly or intermittently and you'll never know, you'll blame your ISP or your laptop or you'll get slow performance and think it's normal. Not worth it.
If these wires were fished into place you can probably use them to pull new ethernet cables. If they are stapled or snaked through holes in studs and joists you'll have trouble using them for pulling and it'll probably be easier to find a new path with snaking tools.
Typical phone jacks and Ethernet jacks look the same from a distance. They are slightly different sizes and the key is the number of pins.
- 2 - single phone line and some digital (but not VOIP) phone systems
- 4 - two phone lines and some phone systems (analog, digital or hybrid)
- 6 - some phone systems, some terminals from ye olden days
- 8 - Ethernet networks, some terminals from ye olden days
As far as I can tell the upper jack of the 2-jack faceplate has 6 wires. Which will not work for Ethernet. I can't tell what the others have. But all is not lost - you may have standard 4-pair cables even if the jacks have fewer than 8 pins. If that's the case then the quality (old junk vs. Cat 3 vs. Cat 5 vs. Cat 5e) will determine whether you can make use of the cables or not.
But in addition to the number of wires, the big issue is the routing. For traditional phone service (analog voice, fax and modem) you can use a star configuration or daisy-chain. Twisted pair Ethernet networks and most phone systems require a star configuration. If you either have a cable (8-wire, preferably Cat 5 or better) going directly between the two locations you want to connect or if all the cables go to one central location then you can use the cables to set up an Ethernet network.
Based on the pictures, it looks like the wires attached to each jack are a pair from a 3-pair cable. While it is possible to run Ethernet on 2 pairs, generally speaking once twisted pair Ethernet became common the usual thing to do was to wire everything with 4-pair cable and mix/match as needed for various phone systems, Ethernet, etc. So a 3-pair cable would generally predate the Ethernet era or was used to save money, in which case it would almost certainly not be even Cat 3 quality.
You might be able to use the old cable to pull new cable. That will depend on how it was installed, which is very hard to tell from the boxes. Testing first to see if any of the wires are connected, and searching to see if they are going to a central location, are the next steps.
These are without a doubt Telephone Jacks. The Jacks in Room A are 6-Wire, so they're RJ25, while the jacks in your office are the older 4-Wire RJ14.
That said as both jacks have RJ25 cabling the only issue here is the jack itself in the office, so you could easily upgrade it to RJ25 or even RJ45 in both rooms (Ethernet wiring uses RJ45) albeit with limited speeds.
There are networking solutions that do allow you to use Telephone jacks for your network, I used to sell PCI cards that did this in 1999! Though you can simply make one yourself using (2) RJ45 Couplers (Female > Female) and by cutting a RJ14/RJ25 phone cable in 1/2 and wiring 4 wires from each end into a RJ45 Ethernet Cable Crimp Connectors following the wiring diagram below to wire up Pins 1,2,3 & 6. As for the phone wires it doesn't mater which you use as long as they're wired the same on all ends you shouldn't have any issues. But here is information and a diagram on phone wiring.
10/100 Base-T cabling only requires 2 pairs (4-Wires), so if you're ok with speeds under 100Mbps, say if for example your internet speed is slower than 100Mbps, then you're not missing out other then perhaps on local traffic between other devices on your network and your Desktop in the office.
It's a shame the rooms are so far apart as a simple solution would have been to use Ethernet to Powerline adapters which would have offered decent performance, but I doubt based on the distance they will work as they need to be on the same line/breaker.
You're likely better off with Wi-Fi for speeds in excess of 100Mbps (and Wi-Fi Range Extender if you need to boost the signal coverage area).
As others have pointed out, these are phone lines.
These rooms are not connected directly to each other, so using the old phone line to pull new ethernet cable is probably not feasible. The cable from each room probably runs back to a hub where the landline phone service splits out. In older homes, there was often a single phone cable that snaked from room to room and could be tapped anywhere to add jacks. That doesn't seem to be the case here, since the cables end at the jacks.
The two-jack room is wired to provide one phone line to one of the jacks and a different phone line to the other. This was likely done to have a regular phone on one line and a modem or fax machine on the other. The extra pins are unconnected, so they probably used the 6-pin jacks because that's what they had on hand.
The single jack with the screw terminals is probably original to the home. It's wired to deliver just the primary line.
So, other than the walls having openings in Room A and B, none of the existing infrastructure helps. You'd have to run an actual network cable (e.g., Cat-5e) from one room to the other, which is likely the hard part. You can then replace the existing jacks with network jacks in each room and wire them to the new cable. That's easy.
These are phone plugs, but the wire used seems to be standard RJ45 CAT5 cable (though I don't see a brown pair, it's hard to tell from the pictures). You should check the markings on the cable, and if they are indeed CAT5, then they could in theory run 100Mbps Ethernet and perhaps 1Gbps for limited distances.
So you would require new wall sockets and rewiring according to the standards, and it could all be for nothing, because the connection might be unreliable. A proper Gigabit connection would need all four pairs to be wired (8 strands) and absolutely no splicing / derivation, there needs to be a single continuous cable from the router socket to the room.
Depending on your budget, property title, type of walls etc. you need to decide if repurposing these wires makes sense and is worth the risk. For example for me, living in a brick house with plastered walls, I would definitely wire them up because the alternative is to install visible wires or turn the whole house into a construction site, ruble and dust everywhere.