Glossary C-Cn0-A | B | C-Cn | Co-Cz | D | E | F-G | H-I | J-L | M | N-O | P-Q | R | S | T | U-Z
B | C-Cn | Co-Cz |
D | E | F-G | H-I | J-L | M | N-O | P-Q | R | S | T | U-Z
- C: Symbol designation for
Capacitance, & Celsius.
- Cabinet: A container that may enclose
connection devices, terminations, apparatus, wiring &
- Cable: An assembly of one or more conductors or optical
fibers within an enveloping sheath, constructed so as to permit use of the
conductors singly or in groups. See also Aerial
- Cabling: The method by which a group of insulated
conductors is mechanically assembled or twisted together.
Memory location set aside to store frequently accessed data for improved system
- CAD: Computer Aided Design.
- CAM: Computer
- Campus: The buildings & grounds of a complex
(university, college, industrial park or military establishment).
Backbone: Cabling between buildings that share telecommunications
- Canadian Standards Association: (CSA)
- Capacitance: the measure of the electrical energy
stored in the dielectric between conductive materials, or in other words, how
well the insulation works. It is measured in pf/ft & the lower the number, the
- Capacitive Reactance: The opposition to alternating current
due to the capacitance of a capacitor, cable or circuit.
Two conducting surfaces separated by a dialectic material The capacitance is
determined by the area of the surfaces, type of dielectric, & spacing between
the conducting surfaces.
- Carrier: A communication medium used to
transmit information in the form of signals.
Sense Multiple Access: (CSMA) A process that allows multiple stations to
access a transmission medium by listening to find out if it is idle before
attempting to transmit packets.
- Carrier Sense Multiple
Access/Collision Detection: (CSMA/CD) In this protocol, stations listen to
the bus & only transmit when the bus is free. If a collision occurs, the packet
is retransmitted after a random time-out. CSMA/CD is used in
- Cascade: A bridged network topology in which LAN segments
are connected end-to-end in order to extend the distance the network
- Cascaded Stars: Topology in which a centralized multiport
repeater serves as the focal point for many other multiport repeaters.
- Cathode Ray Tube: (CRT) A large electron tube that is used
to make images on a phosphor coated screen. Most old computer monitors and
televisions use the CRT for pictures. Currently, CRTs are being superseded by
LCD or Plasma screens.
- CATV: See Community Antenna Television
- CCIRN: See Coordinating
Committee for Intercontinental Research Networks
- CCITT: See Comite Consultatif International de Telegraphique et
- CCN: See Cluster Control
- CCU: See Communications Control
- Central Member: The center component of a fiber cable. It
serves as an anti-buckling element to resist temperature-induced stresses.
Sometimes serves as a strength element. The central member is composed of
steel, fiberglass, or glass-reinforced plastic.
Processing Unit: (CPU) The basis of a personal computer. Available in
- CERT: See Computer
Emergency Response Team
- Certificate of Compliance: (C of C) A
written statement; normally generated by a quality control department, which
states that the product being shipped meets the customer's
- CGI: Common Gateway Interface
- Channel: The
end-to-end transmission path connecting any two points at which an application
specific equipment is connected. Equipment & work area cables are included in
- Channel Service Unit: (CSU) A
component of customer premises equipment used to terminate a digital circuit
(such as DDS or TI) at the customer site; performs certain line-conditioning
function, ensures network compliance with FCC rules, & responds to loopback
commands from the central office; also, ensures proper "ones" density in
transmitted bit stream & corrects bipolar violations.
Standard 8-bit unit representing a symbol, letter, number, or punctuation mark;
generally means the same as byte.
- Character Level Synchronization: A
transmission method in which the sending & receiving DTE's are "synchronized"
during the transmission of one character.
- Character Oriented:
Describing the communications protocol or transmission procedure that carries
control information encoded in fields of one or more bytes; compare with
bit-oriented; also, byte-oriented.
- Characteristic Impedance: The
impedance termination of an electronically uniform transmission line which
minimizes reflections from the end of the line.
- Chat: See Internet Relay Chat
- Cheapernet: See Thin Ethernet
- Checksum: An integer value
computed from a sequence of bytes or "octets". The values of the computed sum
is used at the receiver to detect errors that may occur when a sequence of
contents is transmitted. Protocol software usually computes & appends the
checksum to packets bring transmitted across a network.
(networking): In a virtual circuit; a logical connection between two
endpoints in a network, providing reliable, in a sequence, error-free delivery
of the packets sent over the virtual circuit. (telecommunications) A physical
media connection between two communications devices.
- Circular Mil: A
term used to define cross sectional areas using an arithmetic-short cut in
which the area of a round wire is taken as "diameter in mils .001 inch squared;
hence, one circular mil is equal to pi/4 square miles.
- Citizens Band:
- Cladding: The layer of material, usually glass, that immediately
surrounds the glass core & has a lower index of refraction. The cladding may be
coated with an additional layer, sometimes two, for protection.
Voltages: The predefined voltage level at which a clamping circuit will
- Client: A node that requests network services from a
server. Or In Internet terms, it's an application that performs a specific
function, such as Telnet or FTP. It's the "front-end" to an Internet process.
In more general terms, a client is a computer system or process that requests a
service of another computer system or process. The much talked about
"client-server architecture" refers to a workstation requesting the contents of
a file from a server.
- Client-server computing: A technique with which
processing can be distributed between nodes requesting information (clients) &
those maintaining data (servers).
- Clock: An oscillator-generated
signal that provides a timing reference for a transmission link used to control
the timing functions such as sampling interval, signaling rate, & duration of
signal elements; an "enclosed" digital network typically has only one master
- Cluster Control Node: (CCN) A peripheral
node that is used to control a variety of devices on an SNA
- CMIP: See Common Management
- CMIS: See Common
Management Information Services