What is the difference between RJ45 and RJ11?

The name RJ stands for Registered Jack and is a standardized network interface. RJ45 and RJ11 are two types of crystal joints commonly used in our lives. Their structures and application scopes are different and cannot be mixed, but many people do not understand this, which has caused some unnecessary equipment damage.

The RJ45 crystal head and RJ11 crystal head are different in size, wiring standard and application range. The two are not interoperable, so you should pay special attention when using them.

The RJ45 crystal head is a connector with 8 pins, which is mainly used in Ethernet. “RJ” represents the registered jack, and “45” represents the serial number of the interface standard. The RJ45 crystal head is usually terminated on an Ethernet line and is used to connect various network devices, such as computers, routers, switches, etc.

The RJ11 crystal head is similar to the RJ45 crystal head, but only has 4 pins, which are commonly used to connect telephones and modems. It should be noted that RJ11 usually refers to a 6-position (6-pin) modular jack or plug, but only 4 pins are used. Also, RJ11 is used for the 4-pin version of the modular connector.

1. The structure is different. RJ45 crystal head is a connector with 8 pins, 8 grooves and 8 contacts (8p8c). The RJ11 crystal head is similar to the RJ45 crystal head, but only has 4 pins, 6 grooves and 4 contacts (6p4c). The volume of RJ45 crystal head is larger than that of the RJ11 crystal head.
2. Wiring standards are different. Because the structure of the RJ45 crystal head and RJ11 crystal head is different, the wire sequence standards for wiring are also different. RJ11 crystal head generally only has 6 grooves and 4 contacts (6p4c), and its wire sequence is fixed. RJ45 crystal head has two wire sequence standards when wiring: T-568A and T-568B. By adopting different standards, the resulting network cables are both straight-through and cross-connected. If you want to make a straight-through network cable, both ends of the cable should be connected according to the same standard (T-568A or T-568B). If you make a cross-over network cable, the two ends of the cable should be connected using different standards.
3. The application range is different. The RJ45 crystal head is generally terminated at both ends of the network cable and is used to connect computers and other network equipment. The RJ11 crystal head is terminated at both ends of the ADSL and voice cables to connect a telephone or modem.

Through the layered and in-depth explanation of our Elecbee engineers, I believe you have a deeper understanding of RJ45 and RJ11 connectors. The previous article also wrote about the RJ45 connector with transformer core performance details. If you are interested, you can click read. We will continue to share more knowledge about connectors, so stay tuned!