Glossary

The section of a packet (usually the first part of the packet) where the layer-specific information resides.

The number of decibels by which a system exceeds the minimum defined requirements. The benefit of more headroom is that it reduces the bit-error rate (BER) and provides a performance safety net to help ensure that current and future high-speed applications will run at peak accuracy, efficiency, and throughput. Also called overhead or margin.

A measurement of frequency defined as cycles per second.

An LED design in which the pn (P-type and N-type semiconductor) junction is formed from similar materials that have different refractive indices. This design is used to guide the light for directional output.

A high-capacity communications circuit service such as a private line T-1 or T-3.

High Density also known as HDC or HD

A cable run that connects a user outlet directly with the telecommunications or wiring closet. This cable has no intermediate splices, bridges, taps, or other connections. Every cable radiates out from the central equipment or wiring closet. This configuration is also known as star topology and is the opposite of a daisy-chained cable that may have taps or splices along its length. Home-run cable is the recommended installation method for horizontal cabling in a structured cabling system.

An LED design in which the pn (P-type and N-type semiconductor) junction is formed from a single semiconductor material

May also be referred to as Back Shell, Cover.
A hood is a cover fitted to protect the wire connections to the connector.

Tip: There are four things to consider with hoods. Size, Material, method of Fixing and Cable entry.

i) The size of the hood will be determined by the size of the connector you wish to cover. A 50W Telco will require a 50W Hood and so on.

ii) Hoods are either secured by two screws either side or the Snap fit version this allows the two sides to snap together without the aid of screws.

iii) Hoods may come as plastic in various colours most common is black. Hoods may also be Metal (see Shielded).

iv) Hoods may have 180, 90, or 45 degree cable entry hole.

A connection. In routing terminology, each router a packet passes through is counted as a hop.

The cabling between and including the telecommunications outlet and the horizontal cross-connect. Horizontal cabling is considered the permanent portion of a link; may also be called horizontal wiring.

A cross connect that connects the cabling of the work area outlets to any other cabling system (like that for LAN equipment, voice equipment).

A device that contains multiple independent but connected modules of network and internetworking equipment that form the center of a hub-and-spoke topology. Hubs that repeat the signals that are sent to them are called active hubs. Hubs that do not repeat the signal and merely split the signal sent to them are called passive hubs. In some cases, hub may also refer to a repeater, bridge, switch, or any combination of these.

A mating or alignment sleeve that mates two different connector types such as an SC and ST.

A cable that contains fiber, coaxial, and/or twisted-pair conductors bundled in a common jacket. May also refer to a fiber-optic cable that has strands of both single-mode and multimode optical fiber.