RJ45

RJ45 Interface Introduction

The RJ45 interface is a twisted-pair connector that is the most common in Ethernet cables and networks.

"RJ" refers to "registered jack," a standardized telecommunications network interface that connects network equipment, including voice or data equipment, to services provided by local exchange carriers or long-distance carriers.

"45" is the standard code for the interface.

Registered jacks feature modular connectors and 50-pin micro-miniature ribbon connector types. rj45 connectors, on the other hand, refer specifically to the 8P8C (8-position, 8-contact) modular plugs and jacks that are typically used in Ethernet-based LANs (local area networks). rj45s are normally made of RJ45 is usually made of plastic parts (there are also unique models made of metal materials such as Cat8) and has eight pins in the port number, half of which are used for transmitting data and the other half are used for different technologies or powering network devices.

RJ45 Interface Color Code Identify

The most common wiring schemes are T568A and T568B. They are twisted-pair cable ends that connect to the connector interface scheme. They mainly define the RJ45 connector to connect to the cable when the RJ45 pin arranges each of the eight wires. The main difference is that they are color-coded differently to be compatible with different electrical compatibilities, compared to T568A vs. T568A vs. T568B, the latter being more commonly used. The picture below shows their color differences.

There are two types of connections for both standards. If both ends of the patch cable are wired according to the same standard, it is a straight-through connection; if the standards are different, it is a crossover connection. Some network applications require crossover Ethernet cables, which use a T-568A connector on one end and a T-568B connector on the other. These cables are typically used for direct computer connections without a router, hub, or switch.

Different Types of RJ45 Cable

RJ45 Ethernet cables are equipped with an RJ45 connector on both ends. The most common types used in today's networks are Cat5, Cat6, and Cat7 cables.

Cat5 vs. Cat5e

Category 5 cables were initially designed for 100 MHz frequencies, offering a rated line speed of 100 Mbit/s. Cat5 cables use two twisted pairs (four contacts) and support a maximum range of 100 meters. The Cat5e specification was later introduced with more stringent standards, requiring all four twisted pairs in the cables. Under ideal conditions and over short distances, both Cat5 and Cat5e cables can achieve Gigabit Ethernet speeds thanks to an optimized encoding scheme that accommodates lower signal tolerances.

Cat6 vs. Cat6a

Category 6 cables, which are backward compatible with Cat5e, feature stricter standards and enhanced shielding. Cat6 cables are designed for Gigabit Ethernet, supporting speeds up to 1000 Mbit/s over 250 MHz frequencies. They support 10 Gigabit Ethernet at distances up to 55 meters. Cat6a improves on this by doubling the frequency to 500 MHz and reducing noise interference with grounded foil shielding, which mitigates the distance limitation for 10 Gigabit Ethernet.

Cat7

Category 7 cables are designed to operate at frequencies up to 600 MHz, specifically to support 10 Gigabit Ethernet speeds. In addition to the shielding used in Cat6a, Cat7 cables offer individual shielding for each of the four twisted pairs. They maintain a maximum distance of 100 meters and are backward compatible with Cat5 and Cat6. The Cat7a specification increases frequencies to 1000 MHz, supporting future 40/100 Gigabit Ethernet speeds and improving the transmission of lower-frequency Cable TV streams.

Cat8

Cat8 cables are an economical choice for indoor data center applications, supporting speeds up to 25/40GBase-T and frequencies up to 2000 MHz over distances of up to 30 meters. They are fully backward compatible with previous cable categories.

The Application of RJ45 Cable

The RJ45 connector is an essential part of the Ethernet connection in the medium for transmitting voice and data media. Initially, they were an alternative to the old-fashioned telephone line, in contrast to the higher degree of economy and smaller size. The plug-and-play approach is also much simpler for installation and facilitates high-volume replacement and installation.RJ45 has a much more comprehensive range of applications than RJ11 and is a piece of cake for Ethernet networks, telecommunications, and factory automation. Specifically, it can connect various Ethernet cables, modems, laptops, computers and printers, and other network devices.