RJ45 network connectors are most commonly found at either end of an Ethernet (wired internet) connection. At first glance, they appear similar to the familiar telephone plugs and jacks which connect landlines to walls or switchboards. However, RJ45 connectors are typically slightly larger.
The term RJ45 connector is widely used today to describe both male RJ45 plugs and female RJ45 sockets. The plugs, sometimes called modular connectors, are usually found on the end of Ethernet cables. The sockets or jacks are generally embedded in the device that is being hooked up or mounted to a fixed wall panel.
Definition of an RJ45 Connector
Registered jacks are for telecoms network interfaces. Their job is to link various types of voice and data equipment either to a central hub or directly to each other.
In modern domestic and commercial environments, RJ45 connectors are primarily used for plugging an internet-enabled device directly into hardware such as a modem, router, or server. The connectors themselves are the modular sets of fittings at either end of the physical data connection (Ethernet cable) joining one networked device to another.
As previously mentioned, the term ‘RJ45 connector’ can broadly refer to both male and female versions of these jacks and plugs. In the case of Ethernet networking, the plug fixtures on cable ends are the RJ45 male parts, while the sockets found on the devices themselves are RJ45 female parts.
Technical RJ45 Definitions
Most standard Ethernet data cables have a core consisting of four twisted-pair wire strands, making eight individual wires in total. Male RJ45 plugs separate and correctly terminate these eight individual wires. In other words, RJ45 wiring is based on an 8P8C (8 position, 8 contact) configuration.
Standard RJ45 is defined as a mechanically-keyed variant on a generic 8P8C body. Mechanically keyed essentially means that RJ45 connectors also include an additional tab. This extra tab is designed to prevent them from being mated with any other socket standards which are visually similar, but electrically incompatible. It also prevents accidental disconnection.
For an RJ45 network connector to function properly, the eight Ethernet cabling wires must be inserted into the correct pinout locations on the male connector. With RJ45, this is done following either a T568A or T568B wiring standard. Each of these standards has its own colour-coded wiring convention, achieving two different forms of connectivity.