I just moved into a townhouse. Each bedroom has a CAT5e panel on the wall. I've went up in the attic and I can see the blue ethernet cables running from each bedroom to a central location right above the utility closet, so I'm assuming that the cables I see coming into the utility closet panel are the ones that I see in the attic. Furthermore, whoever set up the panel in the utility closet labeled each wire with the corresponding room.

Here's my confusion: There's a patch panel in the utility closet, but it doesn't have any sort of plug-in for me to plug in my router. Furthermore, the box that the patch panel is installed in has a sticker on it that says "Honeywell security panel". And finally, the ethernet cables are all spliced together. Some have the blue and blue/white twisted pair spliced together with another cable from another room. Is that standard practice for using the ethernet for telephone?

The patch panel has 6 outbound panels and 1 panel labled "input", but the input panel is already used and has a cable going up and out of the box and into the wall. You guys think this has something to do with the security panel or is this just a weird ethernet installation? Seems to me that if they intended on this beign hooked up to a switch/router it would have a RJ-45 input port.

panel1 panel2

2 Answers 2


CAT5e wiring is now commonly used for voice lines, since it's basically the same price and you can run multiple lines over the same cable if you want. All the wiring you've shown is only for voice, not data. If you want to repurpose the cables for data you will need to cut and re-patch the cables to RJ-45 connectors on both ends (in the closet and in rooms).

  • Thanks for the help! Just a FYI. I don't use land line phones in my house and I probably never will. I only have a cell phone. So I did what you suggested: In the closet I pulled the wires out of the patch panel and put RJ-45 connectors on the ends and then just plugged them directly into my router. In the rooms the wires go directly to a wall panel. So I plugged an ethernet cord from the wall to my PC and everything's working fine. I'm guessing that once I get the security company out they may need to do some work to get the ability to make an outbound phone call for security.
    – Wes
    Nov 18, 2014 at 16:09
  • @Wes: glad you're going to get some use out of the cabling. Just so you know, data cables (especially gigabit) are much less tolerant of sloppy cable terminations. The photo you show is fine for voice but may cause a poor connection for data. It's possible the other end of the cables (in the rooms) is also a little sloppy by gigabit standards. You might want to pull off the wall plates to check on them, and/or watch a YouTube video to see how they're supposed to be done for data. But the short version is you don't want to untwist the pairs or the individual wires any more than you have to.
    – Hank
    Nov 18, 2014 at 18:19

What you have there is a set of telephone lines installed all nice and pretty by the electrician, then the security guy came in and junked it all up by splicing in the telephone monitoring in using the crimp connectors.

Security panels are usually wired in to the telephone wiring so that if the panel needs to make a phone call, it can disconnect the house phones and make its call. This is accomplished by splicing in the security panel in to the wire from the phone company and a return wire from the panel provides the telephone service to the rest of the house. (This is usually accomplished with a single cable with multiple conductors in the cable.)

Here's what you should do to make it most functional, assuming you have 0 or 1 phone lines.

  1. I can't see what the wiring is rated for in your pictures, so you'll need to look at the printing on the jacket and see if it's CAT5/CAT5e or CAT6.
  2. Go to home improvement store and buy a patch panel or two. To do project correctly so you don't have to mess with it again, get enough total ports for all of the cables. Make sure the patch panel matches the type of wire you have (CAT5 or CAT6).
  3. Figure out which wire is coming from the outside (telephone company) and which is coming from the security panel.
  4. The blue and blue/white wires from the outside (telephone company) are probably wired to the security panel using crimp-on connectors. That's fine. Leave it.
  5. Connect the return cable from the security panel to the blue section of the telephone patch panel in the input row. (The patch panel you bought in step 2 probably comes with a little plastic tool for pushing the wires in.)
  6. Disconnect the wires going to the rooms from the telephone patch panel. Strip back about 6 inches of each cable. Separate the blue and blue/white wires from the others. Wrap the others in electrical tape to keep them together, leaving about 2 inches exposed at the end. Reconnect the blue wires to the blue section of the telephone patch panel.
  7. Connect the room wires to your new CAT5 or CAT6 patch panel, following the instructions included with it. Do not connect the blue wires; those should remain connected to your telephone patch panel.
  8. Connect your router/switch/whatever to your CAT5/CAT6 patch panel with Ethernet cables.

Here's a crappy diagram:

enter image description here

  • CAT5e wiring won't support telephone and data, it sounds like you're proposing to remove 1 pair of wiring from the CAT5e cable for voice and using the remaining for data. Data requires all 4 pairs of wires.
    – Hank
    Nov 18, 2014 at 15:19
  • You are correct that Gigabit Ethernet requires all 4 pairs. However, 100 Mbit only requires 2 pairs. Thats probably good enough for home use. I'll update my answer. But your statement is literally incorrect: the CAT standards do not specify how to use the wires, only the manufacturing specifications.
    – longneck
    Nov 18, 2014 at 15:23
  • OK good point about the wiring specs. In my mind CAT5e = gigabit ethernet, but of course you can use the cable for anything. However, unless the OP actually needs phone jacks at all of those locations, I would personally recommend doing everything gigabit. Most ISPs now offer connections over 100Mbps, and if you do any sharing or streaming inside the house the extra speed will also benefit.
    – Hank
    Nov 18, 2014 at 15:31
  • longneck, thanks for the info. This is what I was looking for, even though I went with Henry Jackson's answer. I figured it interfaced with the security system somehow. I don't use landline phones in my house.
    – Wes
    Nov 18, 2014 at 16:04

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