AT&T DataPort PCX Modem User Manual page 79

Glossary
L
long space disconnect
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.
loopback test
Any test that verifies the integrity of a device by sending data
from one device to another, and then checking the received data
for errors. Various loopback tests can be used to isolate a
problem to the computer, modem, or telephone line.
M
MNP
Microcom Networking Protocol. Levels 4 through 2 of this
protocol, similar to CCITT V.42, detect and correct data errors
caused by poor telephone line conditions. Level 5, similar to
CCITT V.42bis, includes data compression.
modem
MOdulator/DEModulator. A device used to convert data from a
digital signal to an analog signal so that the data can be
transmitted over a telephone line, and to convert an analog
signal received over a telephone line back into digital data.
O
off-hook
The state of a telephone or modem that is being used.
Issue 2 July 1995
GL-7