RJ45 Cables; Insulation colour:blue

RJ45 network cables are designed to connect computers, servers, routers, TVs, consoles or any other devices to the Internet and local networks. Note that Internet network cables are not the same as phone cables. They differ in their internal structure and terminals (the former is RJ45, and the latter is RJ11). Moreover, unlike network cables, phone cable design does not support fast data transmission.

Obviously, not all Ethernet cables demonstrate the same characteristics, and their selection is really extensive – the TME catalogue includes over 3000 such products. Network cable specifications meticulously define types of networks in which they can be employed, their resistance to external conditions and achievable on-line operation speeds (depending, of course, on given provider's services). Ethernet cables can, or even should be shielded. Cable shielding and its type defines cable resistance to interferences from other nearby cables, devices or strong magnetic fields. If cables are not to be concealed, it is also worth noting the braid colour which can also facilitate their identification. A user can also opt for a flat or circular RJ45 cable.

LAN cable types

Unshielded twisted pair (UTP)

The unshielded twisted pair (UTP) is an electric cable consisting of twisted pairs of conductors, where the entire cable or individual pairs of conductors are not shielded. Conductor pairs are usually twisted by 1 turn every 6-10 cm, and each pair is different. It results in reducing electromagnetic fields and protects transmissions against environmental interferences.

This cable type is commonly used in IT and phone networks. It is used for signal transmission in computer networks of Category 3 (speed 10 Mbps), Category 5 (speed 100-1000 Mbps) and Category 6 (speed 1-10 Gbps). Currently, twisted pairs of Category 5 and 6 are commonly used.

The popularity of UTP mostly results from the fact that it is significantly more cost-effective than other types of shielded twisted pair cables.

Shielded twisted pair

Shielded twisted pair cables are used in Ethernet networks. The electric shield makes signal transmission less susceptible to external interferences and minimises radio frequency interference emissions. As per the ISO/IEC 11801 standard, the following shielded twisted pair cables are specified:

• Single shield: U/FTP;
• Fully shielded: F/UTP, S/UTP, SF/UTP,
• Double shield (single and full): F/FTP, S/FTP, SF/FTP.

The most commonly used shielded twisted pair cable types include:

F/UTP (FTP) – four pairs of conductors wrapped in aluminium film.

S/FTP – each pair of conductors is wrapped in aluminium film, and all four pairs of conductors are coated with a copper shield. For example, such cables are required for Category 7 applications.

Shielded cable application requires that a structured cabling contractor should be aware of applicable principles concerning correct building shielding and electric equipotential bonding. The basic principle of shielding application requires that the shield is earthed correctly at both ends of the cable. Otherwise, the shield acts as a transmitting and receiving antenna, which results in signal quality deterioration. When electric and telecommunications networks do not operate as required, an Ethernet cable shield can act as a protective conductor. One must also always remember that, in addition to the risk of electrocution, the current flowing through a shield causes significant transmission performance deterioration.

Ethernet RJ45 cable categories

Despite the fact that usually only one type of RJ45 cables is used, network cables also come in different categories (as per the European EN 50173 standard). This categorisation results from cable throughput values and possible connection length achievable at given throughput. At present, the choice is usually limited to three options. Ethernet cables are recommended for the following networks:

Category 5: most commonly used network cables

A CAT 5 Internet cable is the most commonly used network cabling standard. Therefore, such cables are used not only in home networks, but also in simple structured corporate networks.

Their throughput limit is reached when the transmission speed exceeds 1 Gbps. However, computers and hard drives are usually the bottleneck of a system, so if cables are to be routed over longer distances, a higher category RJ45 cable could be a good solution.

Category 6: business network cables

This category Internet cables are designed mostly for professional applications. Therefore, they come in handy when large amounts of data need to be transferred. The Category 6a standard also supports transmission speeds of 10 Gbps. It results from the fact that each pair of conductors is individually shielded.

Category 7: Internet cables for most demanding applications

This category Internet cables ensure higher transmission speeds and more effective shielding performance. Thus they are often employed in advanced solutions. All Category 7 Internet cables come with four pairs of individually shielded conductors that additionally share a common shield. As a result, the highest possible protection against interference is ensured.

In this case, network cables come with two standard connector types and are recommended for protecting new building infrastructure.

Category 8: Ethernet cables for data centres

This category network cables are specifically designed for data centres, where the distance between routers and servers is usually short. This results in very high data transfer speeds, without the need of fibre optic cabling application.

The main CAT 8 cable category supports the highest operational frequencies. Data transfer speeds can reach up to 40 Gbps, and such cables are optimally shielded against interferences. Note, however, that this standard supports transmissions only over very short distances.

Network connectors – RJ45 plugs and RJ45 port

In modern domestic and commercial environments, RJ45 connectors are used mostly to connect Internet access-enabled equipment directly to such devices as modems, routers and servers. The term “RJ45 connector” refers generally both to the male and female versions of these connectors and plugs.

RJ45 – technical definition

The majority of standard Ethernet cables come with a core comprising four twisted double wires, giving a total of eight single wires. An RJ45 plug separates these 8 conductors, so the RJ45 cabling is based on the 8P8C configuration (8 positions, 8 pins). An RJ45 socket also comes with a latch preventing connection with other sockets that are visually similar but electrically incompatible. It also prevents its unintended disconnection.

Correct operation of an RJ45 network connector results from the fact that eight Ethernet cable wires are inserted in a plug connector in correct positions. As far as RJ45 is concerned, it follows the T568A or T568B cabling standard requirements. Each of these standards includes its own cabling colour coding and two different connection types.