USER'S GUIDE COMSPHERE MODEM 3821PLUS

Glossary
Glossary-33821-A2-GB20-40 January 1999
configuration option Modem software that sets specific operating parameters for the modem. Sometimes
referred to as straps.
connector An outlet on equipment and cables that provides a connection.
CSA Canadian Standards Association.
CTS Clear to Send. A signal indicating that the modem is ready for the DTE to transmit data.
Customer 1 A user-defined configuration area containing customized configuration options for a
specific application.
Customer 2 A user-defined configuration area containing customized configuration options for a
specific application.
data bank An area within the modem used to store the modem’s firmware.
data carrier A continuous frequency signal that can be modulated by another signal that contains
information to be transmitted.
data compression The elimination of empty fields, redundancies, and gaps in order to reduce storage
capacity needs and the amount of data to be transmitted. Anything that is eliminated is
restored after the data is received.
Data mode One of two general modem operating modes. When in Data mode, the modem transmits
and receives data instead of accepting commands.
DB-25 connector A 25-pin connector that is used to connect a cable which enables communications
between two devices.
dBm A decibel referenced to one milliwatt into 600 ohms. This unit measures relative signal
power.
DCE The equipment (Data Communications Equipment or Data Circuit Terminating
Equipment) that provides the functions required to establish, maintain, and end a
connection. This equipment also provides the signal conversion required for
communication between the DTE and the telephone line. A modem is a DCE.
DCP Diagnostic Control Panel. The front panel of standalone modems such as the 3825Plus.
The DCP permits control and configuration of local and remote modems.
demodulation The process of recovering data from a modulated carrier wave.
dial command modifiers A modifier used in the dial string that instructs the modem how to process a dialed
telephone number.
dial line A communications circuit that is established by a switched circuit connection in the dial
network.
dial network See PSTN.
dial string A series of characters that consists of numbers and modifiers used to dial a telephone
number.
digital signal A signal composed of only two discrete values, representing the binary digits 0 and 1.