So my home is wired with what I thought looked like Ethernet ports. After trial of plugging in my computer and seeing that the ports weren't working as Ethernet cables, I dug deeper.

The wires that run throughout the house are all cat5e. My router is hooked up in the living room with an Ethernet cable running from the ONT port on the back of it to a port in the wall named 1A. Right next to 1A sits a port named 1B. all of these cables run to a central hub in the master bedroom closet.

after finding this hub I realized that all the Ethernet cables running throughout the house are connected to a telephone line switch. and above that switch is a small white box with AT&T on it that one Ethernet cord is plugged into (I'm guessing that's connected to the port that my router is connected to). If I wanted to run a few of these cords that are connected to the telephone hub as Ethernet to the rooms, is the fix as easy as buying an Ethernet switch, unplugging the cables from the telephone switch and plugging them into the new switch, and connecting the Ethernet switch to the small white box i talked about previously?

  • 1
    When you say "telephone switch", what do you mean? Can you add some pictures of the closet setup and wall plate?
    – Machavity
    Apr 1, 2020 at 2:04
  • 1
    Can you add a photo of the inside of one wall plate, showing the wires and the rear of the jack ? And a second photo showing where the cables all come together, in a patch panel probably.
    – Criggie
    Apr 1, 2020 at 2:08
  • 1
    Note this is very similar to diy.stackexchange.com/questions/186831/… and possibly a duplicate. Also diy.stackexchange.com/questions/188621/… seems to cover it too.
    – Criggie
    Apr 1, 2020 at 2:11
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    Pictures would really help this question.
    – Ecnerwal
    Apr 1, 2020 at 2:54
  • not at the house right now, will post pictures in the morning. but to clarify, there are rj-45 jacks in the walls of every room, behind them are 8 terminals where a cat5e cable is connected and runs all the way to a wire drop in the master closet. this is the case for every room. those cat5e cables are connected to a "hub" or "terminal" in the closet that has 6 rj45 jacks for "telephone out" and 6 rj45 jacks for "telco in" Apr 1, 2020 at 3:45

2 Answers 2


For the last couple of decades, many new homes have been wired using UTP cabling because its not significantly more expensive than plain old phone cabling.

So its not uncommon for cat5 and cat6 cable to have only one pair used for a `phone, and the other pairs idle. It will be relatively straightforward to reterminate both ends of each wire.

At the room end, you will need a new faceplate and a new jack for each wire. One jack per cable is correct - ethernet can't be daisy chained like a phone.

There's some cost saving putting a cat5 jack on cat6 wiring, but there's literally no gain putting a cat6 jack on cat5 wires.

At the central point, there should be one run of cable to each remote room. If you don't have this, then someone's done daisy chaining and you need to investigate further.

The wires in the walls should be Solid Core. While it is possible to get plugs for this, the normal best-practice is to terminate the solid core wiring on a patch panel, something like this :

enter image description here

And then to run short stranded patch cords into your switch or router.

Tools: Crimp for plugs, punch-down tool for jacks, a cable stripper for ethernet. Optionally a tone source tool can help with discovery, and a cheap link tester helps show if any of the individual wires are broken. And the usual screwdrivers etc.

Consumables: wall plates, jacks, one patch panel(the most expensive item), a short stranded patch cable per link, a longer stranded patch cable for use in the remote rooms.

You also need to think how your router can connect to this switch. Its possible to use one link to backfeed the LAN through to a switch at the central point. It may work for you to move the router into the central point, though this can cause issues with wireless ethernet signal strength.

This is all a bit generic, but we can be more specific as you provide more details.

  • @Ecnerwal you are correct - sorry I mixed up this and a similar question where the in-wall wires were cat6
    – Criggie
    Apr 1, 2020 at 3:16

It sounds like you have not just Cat5e wires, but RJ45 on both ends. If so, you probably already have everything you need on that end to make it Ethernet.

Ethernet plugs use RJ45 jacks and keystones. They look nearly identical to RJ11 phone because they are designed to be interoperable. RJ11 uses 6 pins, while Ethernet uses 8. Ethernet uses pins 1, 2, 3, and 6 for data. But what about pins 4 and 5? As it so happens, if you plug a RJ11 into a RJ45 (assuming it's been wired to 568A or 568B) it lines up perfectly with pins 4 and 5. In this case, whomever wired this up knew that and went the extra mile to make them RJ45.

In theory, you should be able to plug up your Ethernet to it and use it as-is. You'll want to look at the wiring and make sure it's actually wired as Ethernet on both ends, however. Technically, you'd only need one pair connected to just run phone (I find that unlikely since they could have just used RJ11 and saved time and effort). I would use a laptop and your router to test. Plug up your laptop to the basement and the router to the other end. If it works, you know it's wired correctly.

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