Glossary

Digital Service level 1. Digital service that provides 24 separate 64Kbps digital channels.

A combination of the various pieces of DSX apparatus and its supporting mechanism, including its frame, rack, or other mounting devices.

Any number of DSX lineups that are connected together to provide DSX functionality.

Multiple contiguous DSX bays connected together to provide DSX functions.

A fiber-optic connector developed by the Nippon Electric Group in Japan.

A pair of counter-rotating logical rings.

An FDDI concentrator that offers two attachments to the FDDI network that are capable of accommodating a dual (counter-rotating) ring.

A term used with FDDI networks to denote a station that attaches to both the primary and secondary rings; this makes it capable of serving the dual (counter-rotating) ring. A dual-attachment station has two separate FDDI connectors.

The signal that a touch-tone phone generates when you press a key on it. Each key generates two separate tones, one in a high-frequency group of tones and one from a low-frequency group of tones.

An optical fiber cable manufactured to be used at two different wavelengths. Single-mode fiber cable that is usable at 1300nm and 1550nm is dual-window fiber. Multimode fiber cable is optimized for 850nm and 1300nm operations and is also dual-window fiber. Also known as double-window fiber.

(1) A single enclosed raceway for wires or cable. (2) An enclosure in which air is moved.

(1) A link or circuit that can carry a signal in two directions for transmitting and receiving data. (2) An optical fiber cable or cord carrying two fibers.

 

(2) Duplex Leads – Also known as shotgun or dual

A double loom, two lengths of cable run together to simultaneously send (TX) and receive (RX) data.
If you have a communications line that lets you send and receive data (or talk and listen) at the same time, it's duplex. If you use a cheap speakerphone, you'll notice that as soon as it picks up any noise at your end, it cuts off whatever was being said by the person on the other end. That speakerphone is not duplex.

A two-fiber cable suitable for duplex transmission. Usually two fiber strands surrounded by a common jacket.

Data transmission in both directions, either one direction at a time (half duplex) or both directions simultaneously (full duplex).

With respect to a digital transmission, the product of a signal