NS3000/iX NMMGR Screens Reference Manual - Edition 9 (36922-90040)

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D
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 receiving equipment
can receive it. The resultant 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. A modem is an
example of a DCE.
DDX The national public PSN of Japan.
dedicated printer A printer that can be
used only by one host on the LAN—the one
specified in the Destination Node Name in
that printer’s configuration screen.
default gateway A 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.
destination node name In DTS
configuration, it is either 1) the name of a
host that a user can be connected to by
default (if switching is not enabled for that
user, or if automatic modem connection is
enabled), or 2) the name of the only host
that can access a dedicated printer.
device class A collection of devices that
have some user-defined relation. Device
classes are assigned through use of the
NMMGR configuration program.
device-dependent characteristic A file
specification for which modifications are
restricted because of the type of device on
which the file is opened. For example, data
directed to terminals must have a blocking
factor of one.
device driver A software module that
controls a specific type of input/output
device.
devicefile A file being input to or output
from any peripheral device except a disk.
MPE/iX allows operations to be performed
on the device itself as if it were a file.
device independence A characteristic of
the operating system that allows users to
selectively redirect input/output from a
program, session, or job without regard to
the nature of the device.
device name See PAD name.
Dial ID protocol A proprietary Hewlett-
Packard protocol that provides security
checking and address exchange for dial
links.