I've got cat5e cables and jacks in walls. What should I do to use those for ethernet? Attached is a picture of my cables in my basement. (sorry, the wiring is messy - some company is not doing it neatly.)enter image description here

The background is that I originally used home phone via those jacks in walls. Originally I had Internet and home phone with one company, but the cables and jacks were used for home phones instead of ethernet. Then I switched my home Internet plan to another company for their fibre and discontinued the home phone.

To use those cables for ethernet, I think I need to disconnect those cat5e cables from that panel, add ethernet cable jacks at the ends of the cables, and plug those jacks into my router/modem.

I don't have a home phone any more. Why are those cables still connected to a panel? Is it OK for me to disconnect those then I can use those cables for ethernet?

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    Step one - check for dial tone. It certainly appears to be the case that those are connected to a powered up fiber modem - unless that's not the fiber modem you are presently using. – Ecnerwal Jun 7 at 22:48
  • Yes, it must be the powered up fiber modem: the yellow cable goes to a Wifi modem, the very thin on with green rubber end is the fibre, and the white cable is connected to a battery. However, I am confused by the black cable that is hanging down. Also, could you please explain more on "check for dial tone" part? – sofname Jun 8 at 2:04
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    The black cable hanging down goes to your telephone wiring central point. Thanks for making that clear when you took or cropped the picture, even if you didn't understand that part. So I wonder if you have dial tone (you plug in a phone, it gets dial tone) from your current fiber modem - possibly to support the ability to call 911, even if you don't have regular phone service turned on (a not uncommon state of affairs for "disconnected" phones in the "but we want our emergency services to work anyway" era.) – Ecnerwal Jun 8 at 2:08
  • Thanks for the explaination. It makes sense now. I don't have a home phone any more, so I am not able to check the dial tone. Knowing of the emergency services, now I am pretty confortable to disconnect those cat5e to the telephone wiring central point - for my purpose of using those cat5e for ethernet. Thanks a lot. – sofname Jun 8 at 3:02
  • so I am not able to check the dial tone You don't have a test set ? I thought everyone did... – manassehkatz-Moving 2 Codidact Jun 8 at 3:29

Key is to make sure that each of those cables is a straight run to one location. If so, at the far end of each, install a single CAT 5e jack (small chance you already have an 8-pin jack, but more likely a 2 or 4 pin phone jack) and wall plate. At this location, install a small patch panel like this random example:

Patch Panel

and patch each of the active ports to a small Gigabit switch. One port from the switch goes to your router.

  • Thanks. I think each of those cables is a straight run to one location - I only found 4 jacks in my house. The wall plate for the jacks are labelled with "CAT5E", so the jacks on the wall should be all right - later on I need to verify that. I guess I will go for a patch panel and a switch, as you suggested. – sofname Jun 8 at 4:29
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    The existing jacks may be (hopefully are) wired up properly, but it is possible that only one or two pairs were connected, in which case you may need to punch them down again, which is not a big deal. – manassehkatz-Moving 2 Codidact Jun 8 at 4:46
  • Hope they are wired up properly :) – sofname Jun 8 at 5:43
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    If you go this route, label your wall jacks with the same port numbers as the corresponding patch panel connector. You'll thank yourself later when you have to do maintenance. You can write on the back of the faceplate if you don't want it to be visible. – bta Jun 8 at 21:07
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    It turned out the existing jacks were wired correctly and the problem was the wiring of the patch panel: the wire was not pushed down enough, due to a new but faulty punch down tool. Now I got my fibre speed: 780 Mbps for both downloading and uploading! When I was using wireless, it was ~4Mbps with frequent hikups. Thanks to all... – sofname Jun 9 at 4:20

You would need to terminate all 4 pairs onto Cat5e jacks on both ends, or a small patch panel (but given it's only 4 cables, 4 jacks in a surface mount box would be more appropriate scale) and then patch the central location into a switch connected to your internet router.

If your fiber modem or your wifi router have extra LAN ports, you may not need a separate switch - you might be able to patch into those directly, since they are near the central point.

  • Thanks. After reading about extra LAN ports in your post, I checked my fiber modem and my router again. The fiber modem has some extra LAN ports. However, I think I still need to go for a separate switch - the LAN ports from the fiber modem and the ports from the wifi router must belong to different networks, which will create problems for sharing a printer and aceessing storage between different computers. – sofname Jun 8 at 4:20
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    You might be able to set your wifi device up as an access point rather than a router so that they are on the same network. – Ecnerwal Jun 8 at 10:54
  • That's true. My wifi device can be set to "bridge mode" instead of DHCP, and that effectively turns it to an access point. Unfortunately that disables DHCP, built-in firewall, NAT, etc. I need to do more investigation before I make the switch - I just checked its "network map", and there are 12 devices connected to the wifi device. The number is a big supprise for myself. – sofname Jun 8 at 16:08
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    If the fiber modem has LAN ports, it like has the ability to do DHCP, etc. as well. – Ecnerwal Jun 8 at 17:22
  • Yes, it does. I need to do more investigation before changing the settings - right now my family members are working online from home, so I need to be careful. – sofname Jun 8 at 18:08

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