What is a RJ45 Connector and How to Wire it Different Ways

October 18, 2021 3 min read

If you are an older internet user, you are probably familiar with the Ethernet cable or as it is also known, theRJ45 Connectors. This cable was the main form of Ethernet connection a few years ago when there was no Wi-Fi signal.

It can be used in different places, such as residences and commercial establishments, for example.

You may have seen this cable in your own home. They are usually installed from the distribution point to the home's main router. And it is through the router that the Wi-Fi signal is sent so that wireless connections can be made.

Until a few years ago, the internet connection was made exclusively by cables. As the speed of the internet and equipment such as routers did not have advanced technologies, the cable was the only connection.

But, nowadays, there are still many people and organizations that keep cables as their main connection.

In this article, we’ll share details about RJ45 Connectors and the mechanism of using them:


RJ45 is a type of connector commonly used for Ethernet, i.e. networking. It looks similar to a phone jack, but is a little wider. Since Ethernet cables have an RJ45 connector on each end, Ethernet cables are also called RJ45 cables. With eight pins available in this jack highlights its capacity to connect eight different wires simultaneously. 

RJ45 stands for "registered jack" as it is a standardized network interface. The "45" simply refers to the interface pattern number. Each RJ45 connector has eight pins, which means that an RJ45 cable containseight separate wires. If you look closely at the end of an Ethernet cable, you can see eight wires, each a different color. Four of them are solid colors while the other four are striped.

Each of these settings has a specific number allotted to it. Here’s the sequence of connectivity:

Chart is copied from online source


  1. White/Green (Receive +)
  2. Green (Receive -)
  3. White/Orange (Transmit +)
  4. Blue
  5. White/Blue
  6. Orange (Transmit -)
  7. White/Brown
  8. Brown


  1. White/Orange (Transmit +)
  2. Orange (Transmit -)
  3. White/Green (Receive +)
  4. Blue
  5. White/Blue
  6. Green (Receive -)
  7. White/Brown
  8. Brown


The T-568B is the widely used connector form. However, the other sequence is also supported by some devices. In a few cases, a crossover of both the sequencing type can also work. It is usually possible to establish a connection between two computers when there is no router or switch available.


Here’s the step by step process of connecting RJ45 Connectors:

Step 1: Strip 3-5cm of external insulation of wires. You can use the crimp tool for this purpose. Place the crimp tool over the wire from where you want to strip the insulation. Apply a little pressure and pull away. Be sure not to apply extra pressure that would destroy the inner wires.

Step 2: Now you’ll be able to look at the inner wires. Straighten them with your hand to reveal the core wire from beneath. You might need pliers for straightening them up.

Step 3: Either use T-568A or T-568B sequencing for arranging the wires. Once done, trim your wires so that each of these wires is the same in size.

Step 4: Push the wires into the connector. Do not forget the color sequence while doing so.

Step 5: Crimp the connector to lock the wires in position, and you have your connection established.

Step 6: Repeat the same process on the other side as well.