Configuring and Managing Host-Based X.25 Links - Edition 5 (36939-90054)
Glossary 193
Glossary
that it be consistent. For example,
an automatic cross-validation
occurs when you enter SYSGEN
to assure that information
contained in NMCONFIG.PUB.SYS
agrees with system configuration
data.
CSMA/CD Carrier Sense
Multiple Access with Collision
Detect, transmission access
method used by the IEEE 802.3
LAN standard.
CSN See circuit-switching
network.
CTB The cache transfer bus in
the backplane of an HP 3000.
CUG See closed user group.
data Basic elements of
information that can be processed
or produced by a computer.
Datacommunications and
Terminal Controller See DTC.
data overrun Transmitted data
that is sent faster than the
equipment on the receiving end is
capable of receiving it. The
resulting overflow data is lost. See
also flow control.
Datapac The national public
PSN of Canada.
Datex-P The national public
PSN of West Germany.
D bit Delivery confirmation bit.
Used in the X.25 protocol, the
setting of the D bit in DATA
packets indicates whether
delivery acknowledgment of the
packet is required from the local
DCE or from the remote DTE. It
therefore allows the choice
between local and end-to-end
acknowledgment.
DCE Data circuit-terminating
equipment. The interfacing
equipment required in order to
interface to data terminal
equipment (DTE) and its
transmission circuit. Synonyms:
data communications equipment,
dataset.
DDX The national public PSN of
Japan.
dedicated printer A printer
that can be used by only one host
on the LAN; the one specified in
the Destination Node Name in
that printer's configuration
screen.
default gateway One (and only
one) gateway accessible by a
system may be designated as a
default gateway.The network will
then send any transmitted
messages for which it is unable to
locate a destination through
normal means to the default
gateway in a final effort to
determine a transmission route.
demodulation The process by
which the information-bearing
signal is retrieved from a
modulated carrier wave. The
inverse of modulation.