What is an RJ45 Connector & How does it Work?

October 18, 2021 2 min read

If you deal with Ethernet connections, you must have seen the RJ45 Connectors already. These connectors are mainly used for Ethernet connections.

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

What is RJ45 Connector?

RJ stands for Registered Jack, and 45 is the interface standard. This connector is similar to the telephone jack but is slightly wider than it. With eight pins available in this jack highlights its capacity to connect eight different wires simultaneously.

In each RJ45 Connector, four wires are of solid color while the other 4 are striped. You can wire them in two different ways. 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 establishing a connection between two computers when there is no router or switch available.

How to use RJ45 Connectors?

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.