ZyXEL Communications OMNI 56K USB MODEM, User Manual

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Omni 56K USB Lite
Glossary G
Compatibility If components are compatible, they work with each other.
Compression See data compression.
Cookie
A string of characters saved by a web browser on the user's hard disk. Many
web pages send cookies to track specific user information. Cookies can be
used to retain information as the user browses a web site. For example,
cookies are used to 'remember' the items a shopper may have in a shopping
cart.
CRC Cyclic redundancy check; an error checking protocol.
Crossover
Ethernet Cable A cable that wires a pin to its opposite pin, for example, RX+ is wired to TX+.
This cable connects two similar devices, for example, two data terminal
equipment (DTE) or data communications equipment (DCE) devices.
CTS/RTS Control signal lines on an RS-232C serial interface. These lines are needed to
use hardware flow control.
Cursor A special marker on a display.
Data Bit In asynchronous transfers, a character is composed of data bits (the actual
information) and framing bits (start bit, stop bit/s, parity bit). The framing bits are
needed to recognize whether a character has been successfully transmitted
and where a new character starts.
Data
Compression Re-coding of information. Less data bits represent the same information. ZyXEL
modems use MNP4 and V.42 compression schemes.
Data Packet Block of data that is framed by error control groups. A block consists of up to
256 8-bit groups. Data packets are used in synchronous transfer.
Data Pump
The important module doing modulation and demodulation for a modem. The
data pump is decisive for the quality and the speed of a modem's transfer
capabilities.
DCD Data Carrier Detected - a control signal line of the RS-232C interface.
DCE Data Communications Equipment is typically a modem or other type of
communication device. The DCE sits between the DTE (data terminal
equipment) and a transmission circuit such as a phone line.
Decryption The act of restoring an encrypted file to its original state.
Demodulation Transferring analog signals into digital data bits.