My house has some Cat 5e keystone jacks that are wired for telephone. But the cables in the walls are Cat 5e. (They, the phone company, only wired 2 of the 4 pairs into the jack). I want to 'convert' this arrangement so that I have an Ethernet data port using the Cat5e, by wiring all 4 pairs.

My question is: Can I reuse the keystone jack(s) that is/are currently being used. More specifically, how do I remove the wires from the connectors? (I assume I have to remove the existing wires before I can punch-down new wires into the jack.)

PS - I realize keystone jacks are plentiful and cheap on the Internet, but I ask this question because if I can reuse the jack(s), I might as well.

  • Are they 8c or 6c? The jack for phone is usually not the same jack for Ethernet. See: imgur.com/a/N4eEXAr
    – Tyson
    Jun 14, 2018 at 16:16
  • I believe it is 8c. The wire is labled Cat 5e with 4 twisted pairs, 8 wires total. The keystone jack has eight connectors, and looks very similar to this amazon image (images-na.ssl-images-amazon.com/images/I/…)
    – ender.qa
    Jun 14, 2018 at 16:22
  • 100Mbit Ethernet over Cat5e only needs 2 of the pairs to be wired up (typically the orange & green pairs on pins 1/2 & 3/6). You may not need to do anything to make this work.
    – brhans
    Jun 14, 2018 at 16:23
  • 1
    Also is each jack home run? 5e wire is cheaper than phone wire at this point, and I’ve seen it used for daisy chained phone jacks.
    – Tyson
    Jun 14, 2018 at 16:26
  • 1
    A vs B color scheme really just swaps the pairs used for TX vs RX (the electrons don't really care about the color of the insulation), and 99% of the hardware sold today will auto-detect and swap itself if necessary. But yes if you want 1Gbit you'll need all 4 pairs.
    – brhans
    Jun 14, 2018 at 16:36

1 Answer 1


Yes, you can usually reuse the jacks and cabling

Most of these points have already been touched on in the comments, but here is my full answer:

1 - The jacks can be reused as long as they are in good condition. The main thing you want to watch out for are bent pins where the patch cable (aka the network wire from your computer) plugs in. There can be bent pins that don't affect the 2-wire phone cable but that will affect the 8-wire network cable.

2 - While you only need 4 wires connected for standard networking, if you ever use Power-over-Ethernet or some higher-speed connections (which admittedly may need higher quality wire) then you may need all 4 pairs. I normally (and for many years now) connect all 4 pairs routinely to future-proof things.

3 - You can basically just pull the wires off the jacks, cut off the existing end (just the last inch or 2) to have clean cable, strip more of the outer jacket if needed and then punch down.

4 - The key is to use a real punch tool such as Cable Matters 110 Punch Down Tool with 110 Blade . More $ will get you a better quality tool, but if you use it for just a few jacks then anything will work fine and will work a LOT better than trying to use a screwdriver.

5 - T568A or T568B doesn't matter. Just make sure you do the same on both ends.

6 - Your router or switch needs a separate home run to each device. Ideally you will put that where both cables terminate in one location and that way you can connect a computer at each "phone jack". Alternatively, you can put the router (and other devices connected directly to it) next to one jack and use a patch cable where the two cables are together to go from one jack to the other and put a computer at the other location. Quick ASCII art:

1 --------------------------------- 3
2 ----+

So either router at 1/2 connecting to both 3 & 4 or router at 3, patch 1 to 2, computer at 4.

  • 1
    Thanks for putting together your full answer, which does overlap the comments, but also provides another user who has the same question a very comprehensive answer.
    – ender.qa
    Jun 16, 2018 at 13:50

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