P
ART
III: S
ECTION
C: G
LOSSARY
133
ITU-T
An international organization that defines
standards for telegraphic and telephone
equipment. For example, the Bell 212A standard
for 1200-bps communication in North America
is observed internationally as ITU-T V.22. For
2400-bps communication, most U.S.
manufacturers observe V.22 bis. The initials
ITU-T represent the French name. In English it
is known as the International Telegraph and
Telephone Consultative Committee.
LAPM
Link Access Procedure for Modems. An error-
control protocol defined in ITU-T
Recommendation V.42. Like the MNP
protocols, LAPM uses cyclic redundancy
checking (CRC) and retransmission of
corrupted data (ARQ) to ensure data reliability.
local echo
A modem feature that enables the modem to
display keyboard commands and transmitted
data on the screen. See command En.
MNP
Microcom Networking Protocol, an error-
control protocol developed by Microcom, Inc.,
and now in the public domain. There are several
different MNP protocols, but the most
commonly used one ensures error-free
transmission through error detection (CRC) and
retransmission of erred frames.
modem
A device that transmits/receives computer data
through a communications channel such as radio
or telephone lines. It also changes signals
received from the phone line back to digital
signals before passing them to the receiving
computer.
