rj 45 vs rj11

 

RJ 45 VS RJ 11

 

What is RJ45 and RJ11?

As is known to all, “RJ” means registered jack and the number behind “RJ” means the listing number. So, do you know what is “RJ45” and “RJ11”?

RJ11

RJ11 (Registered Jack 11) usually has a size of 6mm*9.5mm. It features 6 positions and 2 or 4 pins, which is widely used in the telephone system and ADSL/VDSL modem. A 6P4C RJ11 connectors are compatible to make 2 connections with 2 pairs.

RJ45

RJ45 (Registered Jack 45) is the most commonly used connector in network and telecommunication applications. RJ45 belongs to the category of 8P8C connector standard, which means that it has 8 positions and 8 pins/conductors. RJ45 connectors are compatible with many categories of Ethernet cables including Cat5, Cat5e, Cat6, Cat6a, and Cat8.

RJ45 vs RJ11: What’s the Difference?

RJ45 connectors are very similar to RJ11 in their appearance, and you may confuse them. But in fact, they have different designs and functions.

Construction

RJ11 connectors are small, compact, and square-shaped, while RJ45 connectors are rectangular, bigger, and longer. RJ11 is usually a 6P2C or 6P4C standard, which is regarded by Americans to be a useful telephone plug. RJ45 uses an 8P8C standard, which means that it has 8 positions and 8 contacts. Among these eight pins, four pins are used to send and receive data.

Speed

RJ11 connectors can support the speed of about 24Mbps, while RJ45 connectors are designed to achieve the maximum speed of 40Gbps for CAT8.

Wiring Standard

RJ11 connectors have 4 wires and they use a regular wiring standard. RJ45 connectors have 8 wires and they can be arranged to two wiring standards including T568A and T568B. In general, T568B is more common than T568A in daily use.

There are also two connectivity types for RJ45 connectors: straight-through and crossover connections. If both ends of Ethernet cables use the same wiring standard, it is called straight-through; but if not, it is a crossover connection. A crossover cable is generally used to connect a computer to a computer, a router to a router, and a switch to a switch.

Application

It is known that RJ45 and RJ11 are used in different applications. RJ45 connectors are often seen in the network system, linking the modems to other network components. And they are paired with Ethernet cables for stable and high speed. RJ11 connectors have usage for fax machines, telephones, ADSL, VDSL, and other voice systems.

What About Other RJ Connectors?

Besides RJ11 and RJ45, there are various other RJ connectors such as RJ12, RJ14, RJ25, RJ48, and so on. These types of RJ connectors are widely used in North America. Like RJ11, RJ12, RJ14, and RJ25 are modular connectors that feature 6 positions, and all of them are used for wiring a phone line. RJ12 uses a 6P6C standard, which is designed to build a connection for one telephone line with the key telephone system. RJ11 connectors can be replaced by RJ12 connectors as RJ12 also has the function of RJ11. Generally, RJ11 connectors are used for modems and wired telephones at home, while RJ12 connectors are more suitable for centralized telephone systems in offices.