Types of Cabling

section overhead

Links between devices such as repeaters use section overhead, or SOH.

Fiber-optic cable

is composed of one or more flexible transparent plastic or glass fibers. Data is transmitted through the cable by a laser or light-emitting diode, also known as an LED, which sends pulses of light through the cable's central fibers.

category 3

Category 3, or CAT 3, is a UTP cable comprising four wire pairs and can transfer data at up to 10 megabits per second, or Mbps. It's typically used in 10 Mbps Ethernet or 4 Mbps Token Ring networks, and for telephone wiring. However, most CAT 3 installations have been replaced with CAT 5, which provides higher throughput.

category 4

Category 4, or CAT 4, is a UTP cable containing four wire pairs, with support for throughput of up to 16 Mbps. CAT 4 is mostly used for 16 Mbps Token Ring or 10 Mbps Ethernet networks, and offers more protection against crosstalk and attenuation than CAT 1, CAT 2, or CAT 3 cable.

category 5

Category 5, or CAT 5, is a type of UTP consisting of four wire pairs and that's rated for 100 Mbps - although specifications exist for 1000 Mbps over CAT 5. The wire pairs in a CAT 5 cable have a twist-ratio of at least three twists per inch - significantly higher than the wire pairs in a CAT 3 cable.

category 6

Category 6, or CAT 6, is a type of twisted-pair cable containing four wire pairs, each wrapped in foil insulation. The central bundle of wire pairs is covered in an additional foil insulation layer, and a fire-resistant plastic sheath covers the second foil layer. This foil insulation helps ensure resistance to crosstalk.

path overhead

Devices used to assemble and disassemble frames, such as carrier switches or the fiber interfaces of routers, use path overhead, or POH.

category 5e

Enhanced category 5, or CAT 5e, is a higher grade version of CAT 5 designed to support data transfer at speeds of up to 1 gigabit per second, or Gbps. The wire pairs are made from high-quality copper, have a high twist-ratio, and have improved crosstalk and attenuation properties.

category 6e

Enhanced category 6, or CAT 6e, is a higher grade version of CAT 6 wiring that supports data throughput at multiple gigabits per second, or Gbps. Enhanced CAT 6 reduces attenuation and crosstalk, and supports data transfers over greater network lengths than other cable types.

shielded

In a shielded twisted pair, or STP, wire, each twisted wire pair in the cable is wrapped separately in a shield of metallic foil. This guards against EMI and radio frequency interference, or RFI. However, it makes the cable more expensive. The effectiveness of STP cable varies according to the amount of environmental noise that's experienced and the symmetry, consistency, material, and thickness of the cable shielding. If STP cable isn't grounded properly, it can act as an antenna, picking up a variety of signals that cause interference. STP cable has a throughput speed of 10 to 100 Mbps, and a maximum length of 100 meters.

macrobending

Macrobending occurs when light leaks through the fiber cladding, which can occur if fiber cable is bent too much. You can install optical amplifiers to minimize the effects of macrobending over long distances. Optical amplifiers amplify light signals directly, without first having to convert them to electrical signals.

microbending

Microbending occurs when the light source is distorted by a deformation in the fiber, such as a slight bend. This leads to attenuation.

MMF

Multimode fiber, or MMF, has a core with a diameter of between 50 and 100 microns - typically 62.5 microns. A laser or LED generates light that travels in pulses at different angles along the fibers in the cable. MMF is commonly used for the cabling that connects a router to a server or a switch on the backbone of a network.

cable television

RG-6 cable is used for cable television, or CATV, signal distribution. The center conductor for CATV cable is usually steel with a copper coating, and a combination foil/braid shield is made from aluminum.

antenna and satellite television

RG-6 cable is used in transferring signals from satellite dishes and roof-top antennas into homes.

professional video applications

RG-6 cable may connect devices used for professional video applications, such as video editing. This is because it can carry both serial digital interface, or SDI, and base band analog video signals.

line overhead

Single or multiple sections that connect network devices, such as hubs, use line overhead, or LOH.

SMF

Single-mode fiber, or SMF, cabling has a core less than 10 microns wide. Signal dispersion is low due to the narrowness of the core. SMF can support high bandwidths over long distances with no repeaters, and can be used to connect a carrier's facilities. However, it's expensive and not typically used for data networks.

SONET

Synchronous Optical Network, or SONET, is most commonly used in North America. It's defined by the American National Standards Institute, or ANSI, and the Exchange Carriers Standards Association, or ECSA.

SDH

The Synchronous Digital Hierarchy, or SDH, standard is used in most parts of the world, excluding North America.

unshielded

Unshielded twisted pair, or UTP, cabling is the cheapest and most common cable used in computer networking. It's made up of multiple wire pairs, and its small size makes it easy to install. UTP cable lacks extra shielding and isn't very resistant to electromagnetic interference, or EMI. UTP cable is one of the fastest copper-based cables in use. It has a data throughput speed of 10 Mbps to 10 Gbps and a maximum length of 100 meters.