Troubleshooting Terminal, Printer and Serial Device Connections - Edition 4 (32022-90030)

144 Glossary
Glossary
LUG Local User Group. A list
defined for a particular DTC and
card that specifies which remote
nodes this DTC can send data to
and also which remote nodes this
DTC can receive data from. See
also Closed User Group.
M
map, network A drawing that
shows the topology of the
network. For networks managed
by the OpenView DTC Manager a
network map must be created
through use of the OVDraw
capability provided with the
management software. A network
map is also a hardcopy drawing
used when planning a network. It
shows network topology, node and
network names, addresses,
network boundaries (for an
internetwork map), and link
types.
mapping A set of characteristics
that describe a route taken by
messages to reach a destination
node. This set of characteristics is
configured with NMMGR at every
node on a point-to-point network.
One mapping is configured at
each node for every other node on
the network to which messages
will be sent.
MAU Medium Attachment Unit.
A device attached to a ThickLAN
coaxial cable that provides the
physical and electrical
connection from the AUI cable to
the coaxial cable.
M bit More data bit. Setting this
bit in a DATA packet indicates
that at least one more DATA
packet is required to complete a
message of contiguous data.
MDP Modem Distribution Panel;
a distribution panel that serves
as the electrical and physical
interface between a DTC 72MX
mux board (asynchronous
processor board) and up to eight
asynchronous devices for direct or
modem connections. Also called
ADP.
MIT Master Installation Tape. A
magnetic tape containing the
Fundamental Operating System
for an HP 3000 Series 900
computer.
modem modulator/demodulator.
A device that modulates and
demodulates signals. Primarily
used for modulating digital
signals onto carriers for
transmission and for performing
the inverse function at the
receiving end. Modems are
essential for transmitting and
receiving digital signals over
telephone lines.
modulo Value used as the
counting cycle for determining
the send sequence number (N(S))
of frames sent across an X.25
network.
modulation The process in
which certain characteristics of a
carrier signal are altered in
accordance with the changes of an
information-bearing signal.