I am trying to figure out where I would attach the Ethernet cable from my modem to distribute to rest of the house. I'm assuming the blue is the data cable and white is phone but there are two sets of white with one set having 4 wires (phone?) and one set to the left having 8 wires (data?) But why 2 data cables?

I think I would run a cable from the modem to the bottom junction box where it is labeled "from source"??? Not sure how to connect it without tools. Does it require a special tool?

enter image description here

Upper connections

Lower connections

  • 1
    It's hard to see the details of the black punchdown boxes from your photo. Is "from source" an 8 pin jack or another punch down? What do the distribution plates in the rooms look like? Number of jacks, what color wires attach?
    – DaveM
    Jul 10, 2019 at 12:51
  • As a quick explanation, those telephone punch down blocks are like taking the ends of all the wires and twisting them together. They only provide an easy way to have one phone line get distributed to several rooms. Telephone lines are analog, not digital, so you can just splice wires together like that.
    – JPhi1618
    Jul 10, 2019 at 14:36

2 Answers 2


You can't use those black boxes. They are for distributing telephone lines, not Ethernet.

You have two options.

The first is to put RJ45 connectors on the ends of the blue cables. You'll need to buy (or borrow) an RJ45 crimp tool and get some RJ45 connectors. You can crimp on the connectors to all of the blue cables, or just the ones you intend to use. Make sure the connectors you use are compatible with solid core wire.

  • PROS: Probably the simplest method.
  • CONS: Doing an acceptable job of crimping on the connectors takes a bit of experience.

The second is to buy a small patch panel rated for Cat5e. A patch panel looks similar to those black boxes you have now, except that next to each place where the blue cable is connected, there is an RJ45 jack. You'll need a punch tool for this. Some panels or bags of jacks come with a small plastic punch tool which works just fine, but it takes a bit of extra work.

  • PROS: Arguably easier than crimping on connectors.
  • CONS: Takes up more space.

Once you have completed either of the above, you can then connect the cables or the patch panel to your modem or a small Ethernet switch.

Also, you will need to examine the wall plates. The jacks the blue cables are connected to will need to be Cat5e rated or better, and the blue wires need to be connected properly. Frequently this is not done correctly by the initial installer.

  • Also, note that you can't just connect your modem, you'd need a router in front as well. Jul 10, 2019 at 21:21

That's not an Ethernet hub

This is for landline telephone. And they did a bodge job of it. See the "To Expansion" block on the right side of the first one? That's supposed to go to the "From Source" block on the left side of the second one. Then you're supposed to use the 8 remaining positions on each block to punch down up to sixteen (!!) outlets for telephone. They just used traditional phone wiring splices, which is exceptionally dull of them since the punchdown blocks are designed to save them time. Facepalm... By the way those blocks are about $20 each.

However, the good news is that you have the right cables in the walls. All these cables appear to be labeled "Cat 5E" which is adequate for Ethernet.

Powering a hub here

If you want Ethernet, you'll need to get an appropriate Ethernet hub or switch here, which is a completely different thing. Network hubs take power. I don't see any mains AC power in this box. Trying to bring mains power into a box like this opens a big can of worms. So you are better off using Power Over Ethernet (PoE) to deliver power to your hub or switch. You'd want a hub that is itself powered by PoE, however that is hard to find in the sea of hubs designed to plug in and deliver PoE to other devices, and you don't want that. So you can use a "PoE Splitter" inside this box, which extracts PoE from the ethernet cable and delivers the usual 12V plug to power a normal/common Ethernet hub or switch. Choose one that is low power draw (under 2 amps at 12V), so this remains feasible.

To power this, find a location in your house where a power socket and Ethernet are close to each other, and where it won't be objectionable to have a cable draped between them, and then fit a PoE injector there.

Terminate the wire ends with RJ45 (but don't)

enter image description here

Imagine every cable had an RJ45 plug on it. At that point, you could either plug it into a slightly different telephone hub, like this one here that's a brother to the ones you have... or you could plug it into an Ethernet switch. You could change any outlet in the house from phone to Ethernet simply by moving the cable from the phone junction block to the Ethernet switch. Easy Peasy.

I want to pause to get you to understand that solution. Ethernet plugs on the end of each cable, plug it into the above-thing or an ethernet switch. Got it?

OK, except that's not quite the best practice, because Ethernet plugs crimped onto cables are not reliable. Instead, you bring your raw cables down to a patch panel. On the backside of the patch panel is punchdowns just like you see in your existing splice modules. On the front side is RJ45 sockets. Each punchdown goes to 1 socket, and that's it. In other words, this does exactly the same thing as putting RJ45 plugs on the cable, except they are sockets instead**. It's nothing more than that.

Got it?

Because this gets very confusing - you have a whole bunch of equipment - patch panels, telecom modules and Ethernet switches - all of them black and covered with RJ45 sockets. You just have to know the patch panels are the simply ends of your cables, i.e. the "other end" of those Ethernet/phone ports all over your house.

Then, from there, you use short (1-2 foot) Ethernet cords to patch from whichever port you're lighting up, to the Ethernet switch or telecom hub.

Whew. The hard way to do a simple thing, but a) much more reliable, and b) anyone who works in networking will instantly recognize a competent patch panel installation and know what to do with it.

I've worked at a software developer that had fewer Ethernet cables in their punchdown cabinet than your house. Times have changed.

  • 1
    and you'll be better off placing RJ45 plugs on all the unused cables Having done a lot of Ethernet cabling over the years, I disagree. Far better to install a patch panel so the cables are punched down properly with RJ45 jacks on the other side and then use short RJ45 factory made cables to patch between patch panel & router/switch/etc. Putting plugs on long cables is hard to do well and even then, sometimes they'll come apart where patch panels are rugged/reliable and the short factory made cables are cheap enough to toss if their plugs go bad. Jul 10, 2019 at 16:46
  • Is this a good patch panel? newegg.com/p/N82E16812998118
    – Mnm
    Jul 11, 2019 at 14:18
  • @manassehkatz ^^ Jul 11, 2019 at 15:05
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    @Mnm You have the right kind of product electrically. But physically you'd want one that has the same kind of "mounting ears" that your existing telecom modules have, so that it can physically clip into your panel's mounting rails. Otherwise you end up with either a Frankenstein monster of sheet-metal screws, or equipment dangling from wires, and that's how you get flaky patch panel connections. Jul 11, 2019 at 15:30
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    @Harper You're right about mounting - definitely want to make sure they'll match the rails. As far as space, while there are 28 cables coming in, I'd bet only ~ 1/2 are going to be used - unless OP is putting in a full wired phone system (which raises other complications), most likely will only need a few wired phone connections (typically one or two cordless phone base stations and maybe a fax machine) and likely not even every currently wired room will need a network connection. Jul 11, 2019 at 15:36

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