Hello everyone!
RJ45 connectors are recognized as the most common twisted-pair connector for Ethernet cables and networks. So today, I want to share with you some basic knowledge about the RJ45 interface.
What Is RJ45 Interface?
RJ45, also called 8P8C, is a commonly used connector plug for Ethernet connections using twisted pairs. "RJ" means "registration jack" - a standardized telecommunications network interface used to connect voice and data equipment to services offered by local exchange carriers or long-distance carriers. "45" is the number of the interface standard.
8P8C (8 positions 8 contacts) means eight positions (position, which means eight grooves) and eight contacts (contact, which means eight metal contacts).
Physically, the connectors used by the registered jacks are primarily modular and 50-pin micro ribbon connector types. The RJ45 connector is an 8-position 8-contact (8P8C) modular plug and jack for Ethernet-based local area network (LAN). RJ45 cable plugs are usually made of plastic pieces with eight pins on the ports. Four of the pins are used to send and receive data, and the other four are used for other technologies or power network devices.
Difference between RJ45 Connector and RJ11 Connector
The RJ11 is available in a 6P2C or 6P4C configuration for connecting a single telephone line. The RJ45 uses the 8P8C configuration. The main difference between RJ45 and RJ11 is the number of wires in their connectors. Look closely and you will see that the RJ45 has 8 wires inside and the RJ11 has 4 wires, resulting in the RJ45 being larger in size than the RJ11.
Let's see how they differ in detail in the following table:
Notice:
You cannot insert an RJ45 connector into an RJ11 slot, but you can do the opposite. Although the smaller RJ11 size makes it easier to plug into an RJ45 slot, this is not recommended because it may damage a device with an RJ45 slot.
How do I identify the RJ45 connector color code?
T568A and T568B are two common wiring schemes for terminating twisted-pair cables to connector interfaces. These two standards define how RJ45 pinouts line up individual eight wires when connecting RJ45 connectors to cables. These wiring layouts have their own color conventions for electrical compatibility. The T-568B wiring scheme is considered one of the more common.
The following figure shows the differences in color conventions between the T568A and T568B:
Well, from the above, you should know something about the RJ45.
Of course, there are RJ45 cables and cable applications that I haven't shared with you, and I'll post later if I'm interested.
Thanks for reading.
Some of the content and images are from the FS community.
Thanks. 
