Our networks use a standard coloring scheme to ensure compatibility across any device or network connection. In this video, you’ll learn about the colors used in the T568A and T568B standards.
If you look at networks that are installed between different organizations, you’ll notice that the method used for installing the network and even the colors that are used for each pin are exactly the same in every single one of these organizations. That’s because we’ve created standards that provides us with guidelines on exactly how these networks should be installed.
One of these international standards is the ISO/IEC 11801 cabling standards. And in the United States, North America you’ve probably heard of the Telecommunications Industry Association or TIA. The TIA standard for cabling is the TIA 568 standard, which is the Commercial Building Telecommunications Cabling Standard, and you can learn more about it on the TIA website at tiaonline.org.
There is a lot of information in this TIA 568 standard, but in this video we’re going to talk about one very specific part of the standard that deals with what color wires you use on what pins of an ethernet connection. This is referred to as the pin and pair assignments of eight-conductor 100-ohm balanced twisted pair cabling. And as an abbreviation, we often just refer to this as T568A and T568B.
This part of the 568 standard provides you with two options you can use when punching down or applying different colored wires to your ethernet connection. If you look at an ethernet RJ45 connector or a punch down block that’s used for ethernet, you’ll notice that there are two different standards that are addressed. One is the 568A and one is the 568B. These two standards provide us with the colors that we’ll use for our 8P8C connectors. These are 8 position 8 conductor connectors.
Most often, the 568A coloring scheme is associated with horizontal cabling, and in most organizations you’ll probably find that connections for your end users are using the 568B color standard. Ultimately, it doesn’t matter whether your organization chooses to punch everything down with the 568A color standard or the 568B color standard. Both of these standards work exactly the same and have the same functionality, and one is not better or worse than the other.
As a quick fact check, you may find in other training materials and courses that they define an ethernet crossover cable as a 568 color scheme on one side of the cable, and a 568B color scheme on the other side of the cable. In a future video on crossover cables, we’ll visually show you how 568A on one side of the cable and 568B on the other side of the cable clearly is not the pin-out for a gigabit ethernet crossover cable.
The 568A and 568B standards only specify colors. They’re not associated with ethernet crossover cables, and if you want to know how an ethernet crossover cable is designed, you’ll need to look at the IEEE standards.
Here are the color schemes for 568A and 568B. We’re taking this from an ethernet RJ45 connector, which has eight different wires inside of it. And you can see they’re numbered 1 through 8. These are the colors that you would use inside of that connector if you are wiring that connector for T568A. You can see there is a slight difference if you’re wiring it for T568B.
You can see that pins 1 in 2 are different in 568A. We’re dealing with white and green green versus white and orange and orange. We can also see that the orange and green colors have also been changed between these two standards between pins 3 and pin 6. Interestingly, pins 4 and 5 and 7 and 8 are exactly the same between the A and the B standard.
The way that you would tell what standard is in use is you can look at the back of an ethernet cable and see exactly what the colors might be on this particular pin out. You can see on pins 1 and 2 that we have some orange colors, and we can see there’s blue colors in the middle. If we overlay the 568B colors, you can see that they match this particular connector exactly. So you can see that the person who created this cable decided to use the 568B coloring scheme, and if you looked at the other end of the cable, you would see that it uses exactly the same colors on that end as well.
Although many organizations do use 568B, you may run into organizations that prefer to punch everything down with 568A colors. So you may notice on punch down blocks or interfaces that you would install that there are colors assigned for A and other colors assigned for B. You can see on this block that it shows you both color schemes. We have the A color scheme along the top and the B color scheme along the bottom, and you simply have to match the wires when you’re installing it into this particular block.
You can see in this description of the colors that the blue colors and the brown colors are exactly the same between the A and the B standard, and that does correlate back to the colors we were looking at earlier. You can see for A you would put orange wires into these two slots and green wires into the last two. So it looks like in this particular case, this user is wiring this block with the 568A standard.
Here’s another example of a block that has the different colors assigned for A and B. And you can see on this side of the block, we have the four colors that we would use for A or the four colors that we would use for B. If we were to turn this block around, we would see four more colors that associate with the four different connectors on the other side of the block.