Testing Cat 5e Cable

So I'm trying to rig up a better performing home network. I've got a pretty speedy Router, the Asus rt-n66u, but I want more.

I was excited to see Cat 5e cables behind phone jacks throughout the house (literally, every room) but bummed when I discovered they had been daisy-chained, which is a common practice for phone lines.

It also appears the might be stapled, which means using them to pull new wires will be difficult.

Instead, I may just want to use them to run Ethernet between the rooms upstairs. My hope is that they are daisy-chained room to room, and that if I find the center of those two points, I can effectively run drops to each, using the center as a hub, and wifi can cover the rest.

Is there any way of cheaply testing these cables to see where they go? For example, attaching a battery with alligator clips to specific wires within the Cat 5 cable, then checking for voltage at other locations to determine which cable runs where?

Well, I just borrow the cable tester from work.

$14 tester and crimper set

^That thing.

Or if you have enough extra equipment and you're sure the cables are good, you can do something like putting a router on one end and attaching a laptop to the other. If you have connectivity you've found where the cable goes.

I was hoping I could somehow test the routing of the cables before I even worry about attaching ends to them. I want to see if they do in fact go from room to room the way I think they do, then I'd add ends at test for connection.

But for 14 bucks, that kit is hard to go wrong.

You are looking for a tone generator. Consists of a transmitter which you attach to one end which generates a tone, and a probe which you check the other end looking for the tone.

They can get a little pricey (a couple hundred dollars).

If you are willing to spend some time at it, you can take them apart and use a continuity tester.

Toner, may be a bit of a bitch depending on how they are in the walls. Also will make the entire string tone, not just a section of it.

A tone generator still requires at least one end though, and is more useful when you have a big bundle of wires and you're trying to find one wire in it. It also can't test each wire strand in the cable like the tester.

BTW, you are correct that most residential lines are daisy chained, however modern installations usually include 1 last leg in the chain- a return to home from the last link in the chain, making a loop. . If your house is wired this way, it would be much easier.

Way to check- disconnect 1 jack, and see if the rest still work. If it's looped, they will. If the last leg in the chain (the return leg) doesn't exist, all the jacks after the one you disconnected won't work.

But how do I test to see if they work?

Cable tester (there are LEDs for each wire that should light up in sequence) or computer equipment.

If you don't want to modify the cables for testing, you could make some custom cat5-to-phone adapters that will work with the tester units, you could test some of the wires this way but not all of them.

In reply to pheller:

Plug in a phone or your router?

In the kit above there are two continuity tester units. The larger one supplies battery power to the cable and the smaller one has lights that sequence through as the wires receive power. that tells you that the connection is good and if the lights go in the correct order, that you have wired the plug correctly. The larger tester has 2 jacks for testing loose cables - just plug one end into each jack. I used these all the time running and repairing Cat5e for signs, they're awesome.

The toner system will let you track down WHICH cable you should be testing. It's really usefull if you have a big bundle of cable and need to find the right one to some remote point, or to track where a cable runs inside the walls (assuming the walls are thin enough.)

SVreX wrote: In reply to pheller: Plug in a phone or your router?

I've got no phone service, and haven't had a hard-wired phone in oh...7 years. I guess I'd still get a tone if the line has power, though.

I can't test the router because they are hooked up for RJ11 ports (phones) so I'd have go to all the trouble of crimping RJ45 connectors on the lines, then test.

I'm trying to avoid buying anything before I know where these lines go.

This post over on stack exchange kinda answers my question.

I can in fact hook up a 9v battery with alligator clips to two wires and test those corresponding wires on the opposite end to see if I get voltage.

I think building the adapters for the tester unit would be the cheapest solution. You just need the tester & crimper set, 1ft of cat5, and 2 ends of each type. It might be doable for under $20.

pheller wrote: This post over on stack exchange kinda answers my question. I can in fact hook up a 9v battery with alligator clips to two wires and test those corresponding wires on the opposite end to see if I get voltage.

I was thinking about that but I was worried about burning up the wire strands...PoE power is a much higher voltage so the current is lower.

Edit: If it does work you'll have to do 4 different tests per cable run to check each wire, and you'll have to use computer equipment to test if all your ends were installed properly later...that's $20 worth of trouble IMO.

SVreX wrote: BTW, you are correct that most residential lines are daisy chained, however modern installations usually include 1 last leg in the chain- a return to home from the last link in the chain, making a loop. . If your house is wired this way, it would be much easier.

Lets say that I do have a loop to home. So I've got jacks:

A) Basement B) Kitchen (1st) C) Office (2nd) D) Bedroom (3rd)

And I've got A>B>C>D>?

Unfortunately, there isn't another wire running back into the basement, nor is there one running back out to the box outside.

Is this to assume it's looping back to B? So A>B>C>D>B?

All the phone jacks I removed seem to have wires coming into and out of them.

GameboyRMH wrote: Edit: If it does work you'll have to do 4 different tests per cable run to check each wire, and you'll have to use computer equipment to test if all your ends were installed properly later...that's $20 worth of trouble

Why? I hook up the battery at A, and disconnect the wires at B and C, testing the corresponding colors. I'd assume if I get voltage at B, but not C, I've found the wire running from A to B.

That will show you the path of the wire but not test the entire wire to make sure it will work for carrying data. The Cat5 cable has 8 wire strands, your battery has 2 terminals (or more specifically, you only have 2 polarities to test with).

Sounds like I should just find an unused telephone, plug it in, and see what I get. Then if I get something, disconnect the wires downstream to see if I've got a loop or single run.

Then go get a RJ45 tester and crimper and work on data.

Look in the demark and see how many cables. One cable and they all are daisy chained....

demark? demarcation point? I'm not sure I follow.