G
LOSSARY
95
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.
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 flawed
frames
.
