US Robotics 3CP5613 User Manual page 55

facsimile
A method for transmitting the image on a page from one point to another.
Commonly referred to as fax.
fax mode
The mode used by a modem to send and receive data in facsimile format.
See definitions for V.17, V.27ter, V.29.
flow control
A mechanism that compensates for differences in the flow of data into and
out of a modem or other device. See commands &Hn, &In, &Rn.
frame
A data communications term for a block of data with header and trailer
information attached. The added information usually includes a frame
number, block size data, error-check codes, and Start/End indicators.
full duplex
Signals can flow in both directions at the same time over one line. In
microcomputer communications, this may refer to the suppression of the
online local echo.
half duplex
Signals can flow in both directions, but only one way at a time. In
microcomputer communications, may refer to activation of the online local
echo, which causes the modem to send a copy of the transmitted data to the
screen of the sending computer.
Hz
Hertz, a frequency measurement unit used internationally to indicate cycles
per second.
Internet
An electronic communications network that connects computer networks
and organizational computer facilities around the world.
Internet Service Provider
A company which provides dial-up (modem) access to the Internet for a
fee.
7-4
G
LOSSARY
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.
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 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).