Networking cables are networking hardware used to connect one network device to other network devices or to connect two or more computers to share devices such as printers or scanners. Different types of network cables, such as

coaxial cable Coaxial cable, or coax (pronounced ) is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric ( insulating material); many coaxial cables also have a p ...

, optical fiber cable, and twisted pair cables, are used depending on the network's topology, protocol, and size. The devices can be separated by a few meters (e.g. via Ethernet) or nearly unlimited distances (e.g. via the interconnections of the Internet). While wireless networks are more easily deployed when total throughput is not an issue, most permanent larger computer networks utilize cables to transfer signals from one point to another. There are several technologies used for network connections.

Patch cable A patch cable, patch cord or patch lead is an electrical or optical cable used to connect ("patch in") one electronic or optical device to another for signal routing. Devices of different types (e.g., a switch connected to a computer, or a sw ...

s are used for short distances in offices and wiring closets. Electrical connections using twisted pair or coaxial cable are used within a building. Optical fiber cable is used for long distances or for applications requiring high bandwidth or

electrical isolation Galvanic isolation is a principle of isolating functional sections of electrical systems to prevent current flow; no direct conduction path is permitted.John Huntington ''Show Networks and Control Systems: Formerly Control Systems for Live E ...

. Many installations use

structured cabling In telecommunications, structured cabling is building or campus cabling infrastructure that consists of a number of standardized smaller elements (hence structured) called subsystems. Structured cabling components include twisted pair and opti ...

practices to improve reliability and maintainability. In some home and industrial applications power lines are used as network cabling.

Twisted pair

Twisted pair cabling is a form of wiring in which pairs of wires (the forward and return conductors of a single

circuit Circuit may refer to: Science and technology Electrical engineering * Electrical circuit, a complete electrical network with a closed-loop giving a return path for current ** Analog circuit, uses continuous signal levels ** Balanced circu ...

) are twisted together for the purposes of canceling out

electromagnetic interference Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electros ...

(EMI) from other wire pairs and from external sources. This type of cable is used for home and corporate Ethernet networks. Twisted pair cabling is used in short

patch cable A patch cable, patch cord or patch lead is an electrical or optical cable used to connect ("patch in") one electronic or optical device to another for signal routing. Devices of different types (e.g., a switch connected to a computer, or a sw ...

s and in the longer runs in

. There are two types of twisted pair cables: shielded and unshielded.

Ethernet crossover cable

An Ethernet crossover cable is a type of twisted pair Ethernet cable used to connect computing devices together directly that would normally be connected via a network switch, Ethernet hub or router, such as directly connecting two personal computers via their network adapters. Most current Ethernet devices support Auto MDI-X, so it does not matter whether crossover or straight cables are used.

Fiber optic cable

An optical fiber cable consists of a center glass core surrounded by several layers of protective material. The outer insulating jacket is made of Teflon or PVC to prevent interference. It is expensive but has higher bandwidth and can transmit data over longer distances. There are two major types of optical fiber cables: shorter-range

multi-mode fiber Multi-mode optical fiber is a type of optical fiber mostly used for communication over short distances, such as within a building or on a campus. Multi-mode links can be used for data rates up to 100 Gbit/s. Multi-mode fiber has a fairly large ...

and long-range

single-mode fiber A transverse mode of electromagnetic radiation is a particular electromagnetic field pattern of the radiation in the plane perpendicular (i.e., transverse) to the radiation's propagation direction. Transverse modes occur in radio waves and microwav ...

Coaxial cable

Coaxial cable Coaxial cable, or coax (pronounced ) is a type of electrical cable consisting of an inner conductor surrounded by a concentric conducting shield, with the two separated by a dielectric ( insulating material); many coaxial cables also have a p ...

s form a transmission line and confine the electromagnetic wave to an area inside the cable between the center conductor and the shield. The transmission of energy in the line occurs totally through the dielectric inside the cable between the conductors. Coaxial lines can therefore be bent and twisted (subject to limits) without negative effects, and they can be strapped to conductive supports without inducing unwanted currents in them. Early Ethernet,

10BASE5 10BASE5 (also known as thick Ethernet or thicknet) was the first commercially available variant of Ethernet. The technology was standardized in 1982 as IEEE 802.3. 10BASE5 uses a thick and stiff coaxial cable up to in length. Up to 100 stati ...

and

10BASE2 10BASE2 (also known as cheapernet, thin Ethernet, thinnet, and thinwire) is a variant of Ethernet that uses thin coaxial cable terminated with BNC connectors to build a local area network. During the mid to late 1980s this was the dominan ...

, used

baseband In telecommunications and signal processing, baseband is the range of frequencies occupied by a signal that has not been modulated to higher frequencies. Baseband signals typically originate from transducers, converting some other variable into ...

signaling over coaxial cables. The most common use for coaxial cables is for television and other signals with bandwidth of multiple megahertz. Although in most homes coaxial cables have been installed for transmission of TV signals, new technologies (such as the

ITU-T The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Commu ...

G.hn standard) open the possibility of using home coaxial cable for high-speed

home network A home network or home area network (HAN) is a type of computer network that facilitates communication among devices within the close vicinity of a home. Devices capable of participating in this network, for example, smart devices such as netw ...

ing applications (

Ethernet over coax Ethernet over Coax (EoC) is a family of technologies that supports the transmission of Ethernet frames over coaxial cable. History The first Ethernet standard, known as 10BASE5 (ThickNet) in the family of IEEE 802.3, specified baseband opera ...

Patch cable

is an

electrical Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...

or optical cable used to connect one electronic or optical device to another for

signal In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The '' IEEE Transactions on Signal Processing' ...

routing. Devices of different types (e.g. a switch connected to a computer, or a switch connected to a router) are connected with patch cables. Patch cables are usually produced in many different colors so as to be easily distinguishable, and most are relatively short, no longer than a few meters. In contrast to

, patch cables are more flexible.

Power lines

Although power wires are not designed for networking applications,

power line communication Power-line communication (also known as power-line carrier or PLC) carries data on a conductor that is also used simultaneously for AC electric power transmission or electric power distribution to consumers. A wide range of power-line communicati ...

(PLC) allows these wires to also be used to interconnect home computers, peripherals or other networked consumer products. The

HomePlug HomePlug is the family name for various power line communications specifications under the HomePlug designation, each with unique capabilities and compatibility with other HomePlug specifications. Some HomePlug specifications target broadband ...

protocol family was an early PLC technology. In December 2008, the

adopted Recommendation G.hn/ G.9960 as the first worldwide standard for high-speed powerline communications. G.hn also specifies techniques for communications over the existing

category 3 cable Category 3 cable, commonly known as or station wire, and less commonly known as VG or voice-grade (as, for example, in 100BaseVG), is an unshielded twisted pair (UTP) cable used in telephone wiring. It is part of a family of standards def ...

used by phones and coaxial cable used by

cable television Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with bro ...

in the home.

References

External links

The wonderful world of wire
{{DEFAULTSORT:Networking Cables Cables Ethernet cables Signal cables Networking hardware