Paradyne COMSPHERE 3821Plus User Manual page 152

handshaking
HDLC
host
Hz
ISO
ITU-T
JM8
LCD
leased line
LED
local analog loopback
long space disconnect
loopback test
LSD
MNP
modem
modulation
off-hook
on-hook
3821-A2-GB20-30
The exchange of predetermined codes and signals (tones) to establish a connection
between two modems.
High-level Data Link Control. A communications protocol defined by ISO.
A computer attached to a network that shares its information and devices with the rest of
the network.
A unit of frequency (hertz) that equals one cycle per second.
International Organization for Standardization.
The Telecommunications Standardization Sector of the International
Telecommunications Union, an advisory committee established by the United Nations to
recommend communications standards and policies. Before March 1993 it was called
CCITT.
A jack used for leased-line networks. Pins 1 and 2 are the transmit pair and Pins 7 and 8
are the receive pair.
Liquid Crystal Display. The device that permits text to be displayed on the DCP or
SDCP.
A private line connection exclusively for the user. No dialing is necessary.
Light-Emitting Diode. A light or status indicator on the DCP or SDCP that glows in
response to the presence of a certain condition (e.g., Alrm).
Test in which the modem's transmit VF signal is looped to its receiver.
A disconnect can occur if the modem receives an extended space from a remote modem;
for example, when a remote modem is commanded to disconnect, it transmits a
continuous space to the modem before disconnecting.
Any test that verifies a device's integrity by connecting the device's output of one
direction to the device's input of the other direction, then checking the received signal
for errors.
Line Signal Detect. A signal between the DTE and modem indicating energy exists on
the transmission circuit.
This protocol (Microcom Networking Protocol) detects and corrects data errors caused
by telephone line noise and signal distortion. MNP5 includes data compression.
MOdulator/DEModulator. A device that transforms signals from digital to analog form
and vice versa.
The process of varying some characteristics (usually amplitude, frequency, and/or phase)
of a carrier wave to form data transmissions.
The state of a telephone or modem that is being used.
The state of a telephone or modem that is not being used.
February 1998
Glossary
Glossary-5