3Com 3C900B Installation And Operating Instructions Manual page 112

Hz
Hertz, a frequency measurement unit used internationally
to indicate cycles per second.
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
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.
108
G
LOSSARY
ITU-T V.22 . For
MNP
Microcom Networking Protocol, an error-control
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 (
retransmission of flawed 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)
User-programmable random access memory whose data is
retained when power is turned off. On the
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).
protocol
CRC) and
Sportster