RJ Enterprises Blog: RJ45 Connectors 

In networking, technical jargon can be extremely confusing for beginners and those unfamiliar with the industry. For the term RJ45, it’s one particular case that can trip a lot of people up. Luckily, understanding what RJ45 connectors are and how their terminology came to be isn’t exactly rocket science! In this blog, we’ll also be exploring the different types of RJ45 connectors and how you can make the most suitable choice for your networking setup!

What is an RJ45 Connector?

RJ45 connectors/plugs are standardized modular connectors most commonly found at the ends of Ethernet cables. They allow devices like computers to connect and communicate within a network. 

RJ45 vs 8P8C?

In an Ethernet or structure cabling context (like this one!), officially, the RJ45 connectors refer to the 8P8C (8 position, 8 contact) modular connectors. 

Originally, the term RJ45 (or Registered Jack 45) referred to a standardized interface used in telecommunication systems. Like the connectors found in an Ethernet setting, the true RJ45 connectors also featured a 8P8C array pin. However, the true RJ45 connector sports a key that prevents insertion of a non-keyed 8P8C. 

Modern 8P8C connectors don’t follow the same standards, but the similarities between the two has led most to describe the connectors in Ethernet networking as RJ45s despite the technicalities. Conversely, in the telecommunications world, RJ45s refer to… well – the keyed RJ45 connectors. 

For the sake of clarity, the rest of the blog will still refer to the 8P8C Ethernet connector as the RJ45 connector.

Wiring Layouts: T568A and T568B

T568A and T568B pinouts for RJ45 connectors determine the arrangement of each wire within the connector. Matching the correct wiring layout will ensure maximum compatibility and performance.

What are RJ45 Connectors Made Of?

Typically, RJ45 connectors are made up of:

• Plastic housing – Holds internals, like the contacts, in place.
• 8 gold-plated contacts – Enhances conductivity and reduces corrosion for data flow.
• Locking clip - Usually a plastic lever that secures the connector in place when plugged.

The Different Types of RJ45 Connectors

Dimensionally, these connectors have to be the same size to fit into any regular RJ45 ports. However, RJ45 connectors can come in different variations, serving different applications. 

Unshielded RJ45 vs Shielded RJ45

If you’ve read any of our previous blogs or you are just familiar with networking equipment, you’re probably well informed on what metal shielding does for cabling. Similarly, metal shielding in RJ45 connectors helps prevent electromagnetic interference (EMI). 

Of course, choosing the appropriate variation is important in maximizing your network's performance and stability. The general rule of thumb is that unshielded connectors are best used in basic Ethernet applications like homes and offices. On the other hand, shielded connectors are most effective in industrial settings where EMI can be a problem!

2-prongs vs 3-prongs

The contacts in a RJ45 connector can come in two types: either 2-prongs or 3-prongs. 

• 2-prong contacts are designed to be used for stranded-copper Ethernet cables. 
• 3-prong contacts, however, are designed for solid-copper conductor Ethernet cables. Although it should be noted that 3-prong connectors could be used for stranded cables as well. 

Pass-through RJ45 Connectors

RJ45 connectors can come in a pass-through variation. This allows network cables to pass through the connector body via small holes. Pass-through connectors allow users to easily align their cables before terminating them, although a crimping tool is required. For consistent results and convenience, pass-through connectors are usually a favorite. 

Final Words

Despite their quirky history in how it’s term was popularized, RJ45 connectors (or 8P8C Ethernet connectors) are an integral part of wired networking to ensure reliable internet and data transmission. This small piece of plastic (... usually) with 8 gold-plated contacts isn’t more than just an attachment, but they’re essential and widely used in our networks. Hopefully, choosing the right connector for your setup is now easier!