3Com 1.024.1644-00 - Manual (Page 53)

Glossary
56K Voice Faxmodem Internal - User’s Guide 47
ITU-T
An international organisation 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 ‘International
Telecommunications Union - Telecommunications sector’.
LAPM
Link Access Procedure for Modems is 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 Hn.
MNP
Microcom Networking Protocol is 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.
nonvolatile memory (NVRAM)
A user-programmable random access memory which retains data when
power is turned off. On the 3Com U.S. Robotics modem it includes four
stored phone numbers and the modem settings.
OFF/ON hook
Modem operations that are the equivalent of manually lifting a phone
receiver (taking it off-hook) and replacing it (going on-hook).