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G
LOSSARY
7-5
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.
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 .