Keystone Jack Q&A with Don and Dave

Keystone Jack Q&A with Don and Dave

We often get asked questions from our customers through email, live chat, social media, and over the phone. We decided to take them all and throw them at Don and Dave, not literally, to see what they had to say! This time we picked one product in particular to quiz them about. Can you guess what it is? I will give you a hint! It starts with Keystone and end with got it! Our trueCABLE Keystone Jacks! Stick around, you might be able to learn a thing or two!


Don: Hey there YouTubers. It's Don from trueCABLE. Coming back to you again. Butttt, I brought friends. With me I have Dave Harris, Technical Specialist, part of our technical department at trueCABLE, and I've also got Mikayla Moulton from our marketing department. MIkayla is going to be refereeing and asking questions and we're going to go ahead and answer them. The topic is what are Ethernet keystone jacks? Where are they used? What makes them a better termination method than others? So there's a series of questions that we put together that we thought would be very useful for the audience so you can better understand what this “doodad” is and why it's important to you. So I'm going to turn it over to Mikayla.

Mikayla: All right, let's kick it off with our first virtual Q&A, keystone jack edition. So, Dave, we're going to ask you, what is a keystone jack?

Dave: A jack is a receptacle for a plug. In this case, we're talking about RJ45 Ethernet plugs. And the keystone jack is one example of a jack that will accept those. Now, historically, and I'm talking about way back in history, still construction, but when they constructed stone arches, the last stone to go in was called the keystone and it had to be perfectly prepared. It had to fit exactly or the entire arch would fail. So a keystone is for fitment. Here's a keystone in a surface box. You can see this green keystone is right flush with the edge and it completely takes up this hole. That's because a keystone jack is 14 and a half millimeters wide and 16 millimeters tall no matter who makes it. Also, it backset to the load-bearing surface of the latch, 8 millimeters every single time. So, keystone is a standard for both hardware pieces like surface mount box, wall plates, and patch panels. If they say that they're for keystone jacks, that's because of what will fit them and our keystone jacks will.

Mikayla: Thanks, Dave. So for the next one, we're going to go ahead and ask, what are keystone jacks used for?

Don: All right. So keystone jacks, what are they used for? Keystone jacks are used for what's known as rack to jack structured cable or permanent works. Now, what does that look like? Well, I've got some pictures. I'll share my screen and then I'm going to show. So in this picture example, what you've got here is a network setup. You have the equipment, you've got cabling, you've got a cable modem, you've got a patch panel, and you've got your solid copper permanent links coming in that are mounted.

All that stuff is running through the walls of the structure. Then you have this solid copper cable that is coming in and then it's going down into this patch panel. This patch panel is a toolless style which means that it's basically a blank frame that has 12 spots to snap in standard format, keystones. You snap in the keystone after it's been terminated to your solid copper cable and then you can use it to patch into your Ethernet switch with patch cables, like you see here.

Each one of these solid copper permanent links has been terminated to the keystone and then used a patch cord to connect the keystone to your Ethernet switch. What does that look like up close? Well, here's a great side shot example of that. This is the side of the patch panel. You can see the keystone jacks here and you can see the solid copper permanent link cable that's coming into the back of the keystones.

Then you can see on the front of the keystone where the port is. There is a RJ45 connector that's already attached to a patch cable and that's running into the switch. Essentially keystone jacks are a way to make your installation permanent, structured, and ordered.

Mikayla: We're going to go right back to Dave with a new question. This one is, are keystone jacks required when establishing a network connection?

Dave: A simple patch cable is sufficient for establishing a network connection between two devices. The keystone jacks will be in there if part of your network channel is a permanent installation in a business or residence. Keystone jacks make plugging and unplugging patch cords more convenient, but they in and of themselves are not necessary for the network to work.

Mikayla: Don, can you tell us the difference between keystone jacks and RJ45 connectors?

Don: Keystone jacks and RJ45 Ethernet connectors are both two ways of terminating. It's better to understand the similarity first. So both of those items are something you attach to bulk Ethernet cable to give it something so it can actually plug into something else or be plugged in too.

So they're both ways of terminating an Ethernet cable. A RJ45 is a male plug that plugs into something. A keystone jack is a female port that gets plugged into. Going back to the previous example pictures that I have, I'll show you some of the differences here. This is a RJ45 connector that has not been fully terminated to the cable yet, but that is a male connector and that connects on to the end of the Ethernet cable to plug into a keystone jack.

A RJ45 plug is essentially nothing more than a piece of plastic. It has a plastic housing with a retaining clip. It has 8 golden contacts or teeth on it that make contact with the copper conductor wires. RJ45 plugs do not have a category per say, although we have put categories on them on our website. That's only to help our customers shop for the appropriate connector that'll work with our brand cable.

What really matters with RJ45 plugs is fitment, that being the diameter that can be accepted in regards to the thickness of the cable. Also the front of the plug has holes in it, and those holes are critical for proper fitment of the actual conductors and any of them that go through the front of the plug or into the plug to terminate the connection. That's essentially an RJ45. It's a piece of plastic with 8 golden contacts and it's got no secret sauce inside of it. It's just a piece of plastic. Now when it comes to a keystone jack, it terminates very differently. 

This is not mounted in a wall plate or a patch panel, but this keystone jack has been terminated to a solid copper Ethernet cable here. It's been terminated into what's known as IDC (insulation-displacement contact) Terminal. Then a RJ45 plug attached to a patch cable is plugged into the front of that jack. Some of the biggest differentiators between RJ45 plugs and keystone jacks is keystone jacks give you flexibility.

So if you're installing your cabling in their walls, it makes little sense to terminate everything to RJ45’s for multiple reasons. The biggest one actually is due to performance because you're taking a risk by putting RJ45’s on to solid copper Ethernet, especially to both ends. That's never a good idea. RJ45’s have their uses, but not at both ends of an Ethernet cable, and certainly not in a well planned structured cabling system.

That's what keystone jacks are for. They are designed to provide durability and stability to the connection. They also have a circuit board inside which helps keep up the performance of the links. That's very important and that's why keystone jacks have to be category rated, which we'll get into a little bit later. That's essentially the difference between keystone jacks and RJ45’s.

Mikayla: Perfect. So, Don, another question for you. Would you then say that keystone jacks are preferable to using RJ45 plugs?

Don: I mean, obviously each installation is different. So if you're going to be connecting like, let's say you've got two pieces of equipment next to each other, a cable modem and a router. In that case, you just use a factory made pre-terminated patch cord.

You don't need any more than that. Key being factory made pre-terminated. Don't go making your own patch cables because again, if you get into trouble despite everybody's efforts at making the process as simple as possible by documenting the cable diameters and the plugs and then testing cable and stuff like that, the problem is, manufacturing variability can sometimes come into play and things get a little out of tolerance and we can get unexpected results.

Again, like I said, RJ45’s have their place, especially at one end of a PoE run to plug into, for example, a surveillance camera or a Wi-Fi access point so you can provide data and power to the device at the same time. But the rest of the links that are in your installation, if you want to do it right, should be basically keystone to keystone (rack to jack).

So keystone's are very good for keeping your cable runs not only organized, but flexible because let's say you decide to move some stuff around. Let me give you an example. Let's say you decide to run one long cable from a remote bedroom down into your basement and you terminate both ends to RJ45’s. We already know that's not a good idea from a performance standpoint, but it's also not a good idea from a flexibility standpoint.

Let's say you decide to move your television or computer or whatever it is to the other side of the room, but you've only got this much cable sticking up out of your floor or wall. Well, now you've got a problem. Now you have to buy a coupler or another cable, stuff like that. It's easier just to have a port and a wall and then just buy a longer patch cable if you need to.

Not only is it going to cause you less difficulty with data transmission, but it's going to allow you to be able to move things around much more easily.

Mikayla: Dave I'm going to go back and pick your brain a little bit more. The question I have for you is where are keystone jacks mounted? Are they in walls or somewhere else?

Dave: Anywhere you want to plug in a patch cable to a network device. It's good to have a keystone jack ready to be plugged into. If you want to put them in the walls, as many people do, they snap right into wall plates. Attach the wall plate to the wall, and you have an outlet for Ethernet. If you're above a suspended ceiling or maybe out in a warehouse or something like that, the surface mount boxes come in handy. And then if you're close to the switch or router where you're going to have probably several or more patch cables going to jacks, you'll mount those keystone jacks in a patch panel which is prepared for the keystone jack standard, meaning sized properly for them.

So, keystone jacks go where you want Ethernet to be available and you might use a different method to attach it depending on where it's located, whether it's in the wall, in the ceiling or next to the router.

Don: Hey, Dave, I'd like to add and maybe I could show a couple of pictures to folks. So here we've got essentially a patch panel. This is a residential unshielded one where you've got keystone’s that are mounted into a patch panel. This is the head end of the installation.

So basically you have cabling that is running through the structure and it's going into a patch panel. But these cables all go through here and then into the structure and they're going to end up in various places. And that's one of various places.

Mikayla: So Don, I kind of want to go into types of keystone jacks. So on our website we sell Cat5e, Cat6, and Cat6A. So why are keystone jacks rated by category?

Don: Keystone jacks are rated by category because first of all, there's multiple kinds of category cable out there. The ones that trueCABLE sells are the ANSI/TIA 568 recognized ones except Cat8. Each keystone is required to operate at a higher frequency in order to support the cable.

If you go taking a Cat5e keystone that's rated for a lower frequency and attach it to a Cat6A solid copper permanent link cable, you just effectively created yourself a Cat5e overall channel or a permanent link. Everything has to match except the RJ45 plugs. That doesn't matter as far as category, fitment matters.

What matters with keystone jacks is you've got to match the cable category to the keystone jack because keystone jacks have to operate at higher frequencies in order to achieve the higher frequencies the cable can achieve, to get higher bandwidths. Therefore, Cat5e for Cat5e, Cat6 for Cat6, and Cat6A for Cat6A. Each one has a different printed circuit board inside that is tuned to operate as a specific frequency.

Mikayla: Dave, is there a specific way to wire keystone jacks?

Dave: There are two specific ways and they are standardized: T568A and T568B. What they have to do with is the sequence of the different conductors inside the cable. Those conductors are color coded and so is the sequence. You have to choose one or the other, A or B, and fortunately both of them are labeled on our keystone jacks to facilitate wiring them correctly.

Mikayla: So, Don, this one's a pretty big one that we need some help kind of explaining. So our keystone jacks are component rated. What does that mean?

Don: It's actually a bigger discussion than that. Our keystone jacks are a bit special, in a good way. They're not only component rated, but they also impedance match and data center ready, which is kind of like the umbrella of component rating that we use.

There are two different types of keystone jacks out there. One is component rated and the other one is channel level. So component rated keystone jacks are held to very strict limits and test requirements as found in ANSI/TIA 568 2.D connection hardware requirements found in the standard. They have to pass by themselves. In other words, they can't be hooked into an installation and then certified afterward and get called Cat6 or Cat6A rated.

They actually have to achieve that rating twice during production, once on the printed circuit board and then after being constructed to jack. They have to pass strict limits for crosstalk (near end and far end), return loss, insertion loss, and they have to pass strict alien crosstalk requirements. That is something that may not be specifically tested for and documented during manufacture of what's known as a channel level. 

The other thing is our keystones are impedance matching. So when the keystone receives an electrical signal, there's an electrical field and a magnetic field. What the impedance matching does, is it actually impedance matches disparate conductor gauges and types because the standard calls for 100 ohm twisted pair impedance. All Ethernet cable is held to a standard of 100 ohm, with a + or - 15 on it.

So what the impedance matching does is it tries its best to narrow the gap on that + or - 15 variable slop, so to speak. That helps improve performance over your channel because if you hook up a different manufacturer's patch cord that may have a slightly different impedance, it might be 98 ohm. Then you put in some solid copper bulk Ethernet that you're terminating into the other side of the keystone jack that could be 105 ohm. The actual keystone will match those impedances the best that it can to improve data performance or handling over the entire cable run.

The next part of it is data center ready. What that means is, and this is an issue that's occurred many times in data centers, is sometimes inside of a data center (which is not a very large structure) requires short permanent links, sometimes as short as three feet. It's usually not more than 20 feet. So sometimes these short permanent links get tested and they fail due to too much crosstalk going on inside of the cable, bouncing back between the two keystones. This could cause a fail for crosstalk.

So what the “data center ready” part of our keystone does (and that's part of the component rated) is that it allows you to use a short link all the way down to a meter, which is a mere three feet. Now, most people aren't going to be constructing permanent links that are only three feet long, but you can get away with it.

Of course they go to a maximum 90 meters or 295 foot limit of the standard (maximum length based upon ambient temperature). So data center ready is yet another feature of the overall component rating standpoint.

Mikayla: Dave, what is the difference between punch down and toolless keystone jacks because we have two versions.

Dave: The punch down version requires a punch down tool of some type to push the conductors down into the IDC contacts (insulation-displacement contact).

A toolless jack, on the other hand, has a hinged lid on it. Toolless keystone jacks, when closed, have features on the inside that push down all of the conductors into their slots. So a punch down tool is not required for the toolless type. It's not that you can get away without any tools at all, but you don't have to have an expensive punch down tool.

Mikayla: This next question kind of piggybacks off of the question I asked Dave, but what tools are needed to install keystone jacks?

Don: Great question! Dave definitely did flush out the differences between punch down and toolless. So I say let's see some pictures and some of the tools that you might need. So we'll cover the punch down style first.

So when it comes to a punch down keystone jack, you're going to take your eight wires (you have 4 twisted pairs, 8 total wires) and the wires actually get put into these slots and then punched down one of two ways in our punch down keystones. That requires a tool and a tool that a lot of people are familiar with is what's known as a 110 impact tool.

It's a kinetic energy tool. The purpose of it is that has a blade that pushes the conductor into the slot to make electrical contact and then it flush cuts the excess conductor off at the end of the cycle. That means you have to do 8 separate punches to get all 8 wires seated.

Now, a more convenient method would be our rapid keystone termination tool (EZ Termination Keystone Jack Tool), which works only with our jacks. So what it does is it allows you to put a pre-wired jack into the termination tool and then close the handle and it will seat all 8 conductors and flush cut them all at the same time and that greatly speeds up the process.

Now when it comes to toolless keystone jacks, Dave is correct, you do not need your 110 punch down tool because what you've got is a hinged mechanism. So the way a toolless keystone jack is wire and terminated is you will open up the keystone like so. It's got a hinged lid on it and then it's got an IDC wiring cap. That is for the person to wire up the conductors into the appropriate slots like so.

The color code pattern is printed on the side of the cap, which is shown right here. Once you've got that cap wired up, you flush cut off the conductors. You put the cap into the jack housing, you take that lid and you close it and then you have a fully terminated keystone that you can plug a patch cable into.

So at the end of the process, you will also have a zip tie here to help with strain relief and you apply that to the strain relief neck to help keep the cable nice and stable.

Obviously you're going to need some tools. So toolless does not really mean no tools. Toolless means no dedicated 110 punch down tool. Some people get a little flustered when they find out that there actually are tools involved.

You're going to need a cable stripper to strip the cable, flush cutters to prep the cable, and parallel crimping pliers to close the lid if you do not have the finger strength. The pliers are optional, but I recommend it. The pliers close the hinge caps on our shielded and unshielded toolless keystone jacks, as well as our field termination plugs. It's a simple matter of putting the item that you're closing into the tool and the way the jaws close, they close in a parallel fashion, so they don't close on an angle.

Mikayla: Dave, I'm going to go back to you with this question. Can you reuse keystone jacks?

Dave: Yes, as long as they are not damaged in the process of terminating or un-terminating. Our keystone jacks can be reterminated up to 20 times each.

I'm not sure if that's the same for other manufacturers, but I imagine they can be re-terminated at least a few times. So yes, unlike an RJ45 modular plug, if you make a mistake or would like to try to improve your termination, just pull the wires out and start again.

Don: There's a couple of things you should know, but the first thing is per the standard, the component standard, the keystone jack IDC portion, where you actually punch in the wires or the hinged mechanism forces on the conductor cap, that must be durable to the point of at least 20 terminations. That's per the standard.

The RJ45 portion where you plug in a patch cable, the male plug into the keystone, has to withstand at least 750 terminations. That's by the standard. One caveat with our keystone jacks that people should be aware of is that if you do terminate with the thicker 23 or 22 AWG solid copper wire, you cannot go down a size, like 24. This is because the spring wires will have been spread a little too much and could cause improper electrical contact.

So if you use a keystone for 23 AWG, you may re-terminate it, but only for 23 AWG. If you try to go to 24 AWG, you may get inconsistent results.

Mikayla: So Don, if I go to the site right now and I'm on our keystone jacks, I'm going to see shielded and unshielded, how am I supposed to know which one I need for my installation?

Don: That's a really easy one to answer. If you're using shielded cable, you should use a shielded keystone jack. If you are using unshielded cable you should use an unshielded keystone jack. Now technically speaking, there is no harm in using a shielded keystone on an unshielded cable, it'll work. However, it's a bad practice because if someone comes along and sees that shielded keystone may assume that the entire cable is actually shielded.

So best practice is to use shielded for shielded cable and unshielded for unshielded cable, especially when dealing with shielded cable. You have to use a shielded keystone because you have to properly bond the cable shield to the keystone so that it can be bonded to ground. Otherwise the cable shield will not function properly.

Mikayla: All right. This Q&A session is starting to come to an end. So I have one last question. And Dave, I'm picking on you one last time. So RJ45 plugs use gold plated contacts. So why are the IDC contacts in keystone jacks nickel plated?

Dave: It is about the physical properties of the different metals. All of the contacts use a substrate of bronze and the contacts for the RJ45 portion are coated with gold or plated with gold, and that's because gold has the highest conductivity of any available metal. So it's a thin coating of gold on the top of the bronze that maximizes the connectivity at the place where the RJ45 connection is made. At the rear of the jack, where the wires connect to the keystone jack, those are called IDC towers. The reason they're not plated in gold is because of hardness. Not only is gold highest in conductivity, it's also highest in softness. Nickel is harder than copper. When the copper wire goes down into the IDC tower, the hard nickel plating actually cuts into the copper a little bit because the nickel is harder than the copper. If it were gold instead of nickel, the copper conductor wire would wipe the gold right off when you put the wire down in there.

So the reason for nickel is the hardness. Maybe I could have just said that.

Mikayla: Well, that's all the questions I have today. So thank you both for letting me pick your brains and crash your party. And with that, Don, I'll let you end this Q&A.

Don: Hopefully this helped clear things up for you on why keystone jacks are greatly superior to RJ45’s. I mean, RJ45’s have a place. Obviously pre-terminated, factory made, at the end of patch cords is one spot. But if you have to put one on yourself, there are some limited circumstances where you may be forced into doing it. But in general keystone jacks are best because of the way they terminate, their performance advantages, especially with the component rating in ours.

Hopefully you found this educating. Be sure to check our cable academy, which has much more about lengths, temperatures, conduit loading, how to terminate keystone jacks, you know blow by blow with a video. So our cable academy is a great resource to continue the research. There are 170 plus blogs.

I will say you have a wonderful day and HAPPY NETWORKING...

trueCABLE presents the information on our website, including the “Cable Academy” blog and live chat support, as a service to our customers and other visitors to our website subject to our website terms and conditions. While the information on this website is about data networking and electrical issues, it is not professional advice and any reliance on such material is at your own risk.

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