RJ45 Wiring Made Simple

by Network Cabling Guy on September 26, 2011

RJ-45 Wiring Made Simple

In the network cabling arena, the pinouts of varying connectors and methods can be very confusing at times. In this post we will discuss in much detail the wiring methods  of RJ 45 and related connectors. I will not only show you how to perform the RJ45 wiring but understand the reasons behind the different pinouts. You can use this information to make your own network patch cables, terminate jacks, troubleshoot or add to your arsenal if you are a cabling technician. So, without further delay let’s get started.

What you will need to get started

EIA/TIA 568A and 568B

The first thing to understand is the EIA/TIA 568A & 568B Standards and which one you are working with. The chart below will help illustrate the difference between the two. In a standard Cat 5e or Cat 6 cable there are 4 pairs or wires or 8 individual wires. The pair colors are Blue, Orange, Green & Brown. There is a white striped color in each pair and a solid color. (ex. White Blue & Blue)The only difference between the 568A & 568B standard is that the Orange & Green pairs are swapped when terminated. See the two illustrations to better understand this process.

Usually an organization will have either a 568A or 568B pinout on their existing system, not both. With new network cabling installation the pinout you want should be in the scope/specifications of the job. If not you may need to ask the customer which pinout they would like. To be honest most customers will not know what you are talking about and you will choose for them. In 95% of all locations you will see a 568B pinout. Always make sure to check this before you start terminating any sort of network cabling as this could be a real problem if the cables are terminated with the wrong pinout.

RJ45 Connector

One very important detail to remember is that a female connector and a male connector are a mirror image of each other. To get a visual on this, the male connector would be the end of the patch cable and the female connector would be the jack in the wall outlet. See the image here to better understand.

 How to Terminate a Patch Cable

First you will need to determine what type of network cable you will be using. Most network cabling installations today use Category 6 cable over Category 5e. Once you determine this you can purchase the correct RJ-45 wiring plugs. Then follow these steps:

Cat 6 Patch Cord

  1. Cut the end of the cable as straight as possible using a good crimping tool. This is important because it will allow all of the conductors to sit evenly up against the front of the connector. If not one of the conductors may not make contact with the crimping pins and you will end up with a short.
  2. Score the jacket of the cable all the way around, about 2″ back from the end with a scoring tool or your data scissors. You should then be able to snap the jacket clean off and discard. There will be a pull line inside. You can cut this flush with the bottom of the cable jacket.
  3. Untwist all the wires just to the base of the jacket. You will then need to straighten them as much as possible by pulling them through your thumb and index finger a few times.
  4. Line up the conductors by color according to the illustrations above. Once you have the conductors lined up cut them to approximately 1/2″. Any longer you may experience crosstalk and other problems.
  5. Holding the RJ-45 plug in one hand facing away from you slide the conductors into the plug all the way up to the front of the plug. Inspect to make sure all conductors made it up and they are all even. Double check this as you will have to cut the plug off and restart if this is wrong.
  6. Once you confirm the conductors look flush and even insert the RJ-45 into the crimp tool. Make sure the plug is all the way into the tool. Once the plug is in squeeze down and crimp the RJ-45.
  7. Repeat this process on the other end of the cable.
  8. Using a cable tester, run a test on the cable to make sure it is done correctly.

Note: For Category 6 RJ-45 wiring there is sometimes 3 parts to the RJ-45. Follow the directions that come with the RJ45 connectors. It won’t be much different from above. There is an extra piece to separate the conductors before you slide them into the connector. Our Youtube video here will show that process. You can also click on the picture above for the video.

Crossover Patch Cable

Crossover Patch Cable

The term crossover patch cable refers to a patch cable that is wired differently on both ends. These are often used for connecting two pieces of equipment and not PC’s. Follow all the directions above. The only difference is you will terminate one end using the EIA/TIA 568A color scheme and the other end using the EIA/TIA 568B color scheme.

A straight through patch cable would be a patch cable that is wired the same on both ends. This would mean you would use either 568A or 568B color scheme on both sides.


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