|
capacity
The term "capacity" refers to using the data-carrying capability of a component or communication link. It is the number of bits the component or link can process in a period of time.
carrier wave
A carrier wave is a consistent waveform that can be modulated to carry a signal. To receive a signal, a receiver must be tuned to the same carrier wavelength used by the transmitter.
cell
A cell is a unit of data similar to a frame. It is very small (53 bytes for ATM) and fixed in length. Cells are typically associated with ATM technology.
central office (CO)
A CO is a telephone company facility where local loops are terminated. The function of a CO is to connect individual telephones through a series of switches. COs are tied together in a hierarchy for efficiency in switching. Other terms for a CO are "local exchange," "wiring center," and "end office."
channel
A portion of the total bandwidth of a physical transmission path, used to carry a single signal is referred to as a channel. Channels are also called links, lines, circuits, and paths. A physical connection, such as a cable, may support more than one channel.
channel service unit (CSU)
A CSU is a device that connects to the end of a T1 or T3 line, between the line and a DSU. The CSU maintains an electrical connection on the line and functions as a repeater, regenerating and amplifying both incoming and outgoing signals. A CSU is usually combined with a DSU in a device called a "CSU/DSU."
cladding
Cladding is the clear plastic or glass layer that encloses the light-transmitting core of a fiber optic cable. The cladding has a lower refractive index than the core, and reflects the light signal back into the core as the light propagates down the fiber.
client
A client is any program that requests a service or resource from another program, either on the same computer or a different one. This term is often used to refer to the computer that hosts the client program; however, a client program may also run on a computer that normally functions as a server. See server.
coder/decoder (codec)
A codec is a hardware/software device that takes an analog signal and converts (codes) it to digital format for compression and transmission. On the receiving end, the digital signal is put back (decoded) into the original analog signal.
collapsed backbone
A collapsed backbone is a network topology that uses a multiport device, such as a switch or router, to carry traffic between network segments or subnets. This is in contrast to the original backbone that, in the case of Ethernet, consisted of a single common bus cable to which nodes were connected.
collision domain
The portion of a network where all nodes receive every frame transmitted is referred to as collision domain. A bus, hub, or group of interconnected hubs forms a single collision domain.
common carrier
A company that must offer its services to all customers at the prices and conditions outlined in a public record is referred to as a common carrier.
compiler
A compiler is an application that converts code written in a programming language (source code) into machine-level instructions (an executable program).
compression
The process of reducing the number of bits required to represent data, without altering the information conveyed by the data, is referred to as compression. The primary reason for using compression techniques is to optimize the use of a communication channel.
connection-oriented
A connection-oriented data communication mode is one in which the sending and receiving computers stay in contact for the duration of a session, while packets or frames are being sent back and forth.
connectionless
Connectionless transmission treats each packet or datagram as a separate entity that contains the source and destination addresses. Connectionless services can drop or deliver packets out of sequence.
core
The innermost layer of a fiber optic cable, made of clear glass or plastic, is the core. It carries light signals down the fiber.
criminal hacker (cracker)
A cracker is someone who gets fun or profit from breaching a secure system and possibly stealing information or damaging data.
|