Network Cabling Tools – CompTIA Network+ N10-006 – 1.5

| March 31, 2015


You can’t manage a network unless you have the right tools for the job. In this video, you’ll learn about using wire crimpers with modular connectors, punch-down tools, and using a TDR to identify cabling issues.

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If you’re working with your physical infrastructure to any degree, you’re going to need the right tools. And in this video, I’ll give you an overview of some of the most popular cabling tools. If you’re going to be working with RJ45 or RJ11 cables and you need to put those connectors on the end then you’re going to need a good crimper. This is the device that pinches that connector on to the end of the cable once you’ve put all the wires inside of that RJ45 connector.

There are also crimpers for coax connections and fiber connections as well, but we most see this associated with connecting up an ethernet connection, the RJ45 connector, to the end of the wire itself. And this allows you to make the wire as long as you like and then put your own connectors on to the end. It works by pushing the metal prongs on the RJ45 connector into the insulation of your wires and connecting them to the copper that’s inside.

It’s on there permanently. Once you make the connection, you can’t remove it and change it and put it back. If you make a mistake, you’ve got to cut off that connector and put a brand new connector on to the end. Before you put the modular connector onto those wires, this is what it looks like. And you can see their raised up just a little bit.

When you crimp this, it will push down those pieces of copper. And at the end, you can see it’s got little teeth that are going to dig into the insulation that’s around those copper cables. And that’s how it makes that electrical connection. It then becomes flat on the top and that’s what you would put into the connection where your ethernet jack might be to make that electrical connection.

Here’s what this looks like after we’ve made the crimp. We’ve put all the wires into their proper places, and we’ve made the crimp. And you can see that copper connector on the outside of the RJ45 isn’t sticking up anymore. It’s been pushed into the connector itself and the prongs have gone into the insulation to make that electrical connection. Notice, also that while we printed there was a connection at the bottom a piece of plastic that has been pushed right into the cable. It’s not breaking the cable, but it’s pushed up just enough so that the cable will not pull out of that connector once we have everything crimped and in place.

If you’re planning to crimp cables yourself, make sure you get a good crimper. There’s nothing worse than getting all of those wires into the connector and then you’re using a substandard crimper, which loses all of the work that you spent all that time doing. You also want a good pair of snips. These are electricians scissors. These are the ones that I use and a good wire stripper can help as well so that you can put this on the wire. And with a couple of twist, you’re now into that sheet. Then you’re able to gain access to the wires inside.

You also want to make sure that you’re using the right connectors for the cable that you’re using. Different types of cabling use different types of connectors. They look very similar, but there are minor differences. Especially, if you’re going to use either category five or category six. There’s completely different connectors for those. And another thing that is extremely important when it comes to crimping is that you practice, practice, and practice.

It takes a bit of time to work with the wire and become accustomed to using them in getting a good crimp. But once you finally get the hang of it, you’ll love it. You can make whatever linked wires you would like and customize it for exactly where it needs to be. If you’re working in a larger environment, you may need a punch-down tool. And even in a small environment like mine, I still have jacks in the floor that I need to have a punch down tool for. And this is used to put the wire into one of these blocks or into one of these connectors, either a 66 block or 110 block.

This can be a very tedious process, especially if you have a lot of wires you’re working with. And it’s one where you may be sitting there for awhile and punching down wire, after wire, after wire. This is a pretty efficient process though when you’re punching in a wire. It’s putting it into the block. The block is getting into the insulation so you’ve got a good electrical connection. And then the punch-down tool is also sniping the end of the wire so that you don’t have pieces everywhere on the side of your blocks. It makes it for a very simple process, and if you could get all of your wires set up you can punch them down very quickly and you’re done.

With all these little wires going everywhere, it’s important that you organize or at least are able to follow some of the organization that may be already on your punch-down blocks. You can see this one even has the colors all set up for you in the back. So you don’t even have to think about where the wires might go. You simply follow the diagram that’s on the back and it will put exactly everything in its place.

You also want to be sure you maintain the twists in the cables that you’re using when you’re punching it down in the block. After all, it’s those twist that allows us to minimize the amount of interference that’s received on each side of that connection. And you can see here they did a really good job on the punch-down block, because those twists are still in place all the way down into the block itself.

In most environments, you’ll have punch-downs in a lot of different places. And you may have a large number of them back on the wall of the data center. So you want to be sure to document as much as possible may want to tag the cables themselves. And very often, if you look at the wall behind the punch-down block, it’s usually a piece of wood and people have written on the wood exactly where these wires are going. Whether you’re using this graffiti or whether you’re tagging the cables themselves, you want to be sure that everybody understands what’s in place after you’ve left.

Another great tool for cabling is the TDR and the OTDR. TDR stands for time domain reflectometer. And for a fiber connection, it is an optical time domain reflectometer. The TDR is used to give us an idea of the cable links that we might be using. It can certainly tell us how long a cable is from one side to the other. It can also tell you if a cable been spliced and how far down the line the splice has occurred. It may also tell you information about the impedance of the cable and how much signal loss you’re getting from one end to the other.

We often use these if we need to certify an installation. So we can put the cable in and then we can verify that we’re getting a cable that will be able to support 100 megabit, gigabit, or even 10 gigabit speeds through that cable. A TDR works by sending a signal down a cable or fiber and looking for the reflection that’s coming back. It sends this ping and it’s able to discern what it’s seeing all the way through the cable by examining what reflection it’s getting back.

This reflection can allow us to calculate time and distance so we can tell you how far away and into the cable might be or how far away a problem with a cable might be by just looking at this reflection. An OTDR is obviously doing exactly the same thing, but instead of sending an electrical signal is sending light down and looking for the reflection of light that’s coming back.

We can look at this visually. We’ll send a signal through and when it hits a problem some of the signal is reflected back and the rest of the signal is sent down the line, although you can see it’s not as much signal as it was at the beginning. Let’s do that again. I’m going to send a strong signal. It hits a problem the signals decreased and there’s the reflection. And it’s that reflection that the TDR uses to now provide you with information about what’s happening on that particular cable.

These TDRs are not inexpensive devices. It may cost many hundreds of dollars to get a fully functional time domain reflectometer commoner, and it costs even more for the optical versions of these. These may also require additional training. It takes a lot to understand exactly what’s happening at the physical layer.

And you may also need training on how that operates the TDR itself, but these are very powerful tools. And if you’re trying to solve a problem at the physical layer, this is exactly the right tool for you. Especially, if you’ve installed so new copper or some new fiber and you want to be assured that it’s going to operate properly once you have your equipment in place. The TDR is the perfect device to certify that cable plant.

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Category: CompTIA Network+ N10-006

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