What is an RJ45 Connector?

Ethernet is a technology that allows the connection of multiple devices in a Local Area Network (LAN) OR Wide Area Network(WAN). The Ethernet has also some protocols that are also responsible for effective communication between the devices in the wired network. RJ stands for Registered Jacks. They are mainly used to connect to different types of networking media. Different types of RJ are available, including RJ11, RJ45, RJ48, RJ61 etc. The classes are usually classified based on structure, functionality and suitability. These jacks are generally used for Ethernet Networking.

RJ45 Connector

RJ45 stands for Registered Jack 45 and is the most commonly used connector in wired networks. The jacks are mainly used to connect to the Local Area Network (LAN). It was earlier devised for telephones but is now widely used in Ethernet Networking. The 45 in RJ45 basically stands for the listing number. The width of RJ45 is usually greater than that of the telephone cables or other Registered Jacks. Compared to additional jacks the bandwidth provided by these is high and the range is usually 10 Gpbs. Because of speed and enhanced security, they are used to connect personal computers to servers, routers etc. These jacks are mostly used in Star Topology.

Structure of RJ45

RJ45 has a transparent plastic structure and is an 8-pin connector. It is an 8P8C connector and the number of wires that can be connected is 8. The jacks are mostly used with Shielded Twisted Pair cables or Unshielded Twisted Pair cables. If we take a close look at the end of the Ethernet cable connected to the RJ45 we can see the 8 wires out of which 4 wires are solid coloured and 4 are strip coloured. The classification of RJ45 is done based on the wiring. Some of them include Cat 5e, Cat 6, and Cat 7.

The colours of RJ45 wiring include White/Green, Green, White/Orange, Blue, White/Blue, Orange, White/Brown, and Brown. Now coming to the colouring of the wires two colour code schemes are used. On is RJ45 T568 A and RJ45 T568 B. They are different because of the position change of orange and green wires. In RJ45 T568 A the green color wiring comes before orange wiring and in the case of RJ45 T568 B orange wiring comes before green wiring. Another difference between the two is RJ45 T568 A provides backward compatibility with the old wirings whereas RJ45 T568B offers more resistance to noises in the signals.

Color-Coding of the Wires in the Connectors

Pin	T568B	T568A
1	white with orange stripe	white with green stripe
2	orange	green
3	white with green stripe	white with orange stripe
4	blue	blue
5	white with blue stripe	white with blue stripe
6	green	orange
7	white with brown stripe	white with brown stripe
8	brown	brown

Advantages of RJ45

Initially developed for telephones, RJ45 is now widely used in wired networking. Therefore it has many advantages and some of them are as follows:

• RJ45 connectors provide much greater speed.
• They are cheaper as compared to other connectors.
• Supports much greater bandwidth (100 Mbps)
• They are very reliable.

Disadvantages of RJ45

There are many disadvantages of RJ45. Some of them are as follows.

• RJ45 have compatibility issues. They are not compatible with other connectors.
• These connectors are neither weatherproof therefore they do not have much durability.