Glossary

Signals that are dependent on some uniform timing or carry their own timing information embedded as part of the signal.

A separate ground conductor that is insulated from the equipment or building ground.

The ability of a circuit or component to reject interference.

In fiber optics, a device that permits only forward transmission of light and blocks any reflected light.

A term used with Ethernet to describe the act of continuously sending data or sending Ethernet frames with a frame size greater than 1,518 bytes. When a station is jabbering, its network adapter circuitry or logic has failed, and it has locked up a network channel with its erroneous transmissions.

A receptacle used in conjunction with a plug to make electrical contact between communication circuits. A variety of jacks and their associated plugs are used to connect hardware applications, including cross-connects, interconnects, information outlets, and equipment connections. Jacks are also used to connect cords or lines to telephone systems. A jack is the female component of a plug/jack connector system and may be standard, modified, or keyed.

The outer protective covering of a cable, usually made of some type of plastic or polymer.

A cable carrying optical fiber in a ribbon arrangement with an elongated jacket that fits over the ribbon.

A slight movement of a transmission signal in time or phase that can introduce errors and loss of synchronization. More jitter is introduced when cable runs are longer than the network-topology specification recommends. Other causes of jitter include cables with high attenuation and signals at high frequencies. Also called phase jitter, timing distortion, or intersymbol interference.

Any joining or mating of a fiber by splicing (by fusion splicing or physical contact of fibers) or connecting.

Also known as Mains lead, Power chord/ lead.

The kettle lead is used to connect the mains supply to the computer. Consisting of a C13 Socket to a UK Mains Plug.

A strong, synthetic material developed and trademarked by DuPont; the preferred strength element in cable. Also used as a material in body armor and parts for military equipment. Also known by the generic name aramid; see also aramid yarn.

A mechanical feature of a connector system that guarantees correct orientation of a connection. The key prevents connection to a jack or an optical-fiber adapter that was intended for another purpose.

Also known as an RJ45 Socket.

Keystone Jack, These jacks can be panel, plate or equipment mounted and are available in UTP (Unshielded Twisted Pairs) or STP (Shielded Twisted Pairs) versions. The wire used is connected via a built in punch down block (110 type).

Kilohertz; 1,000 hertz.