Configuring and Managing Host-Based X.25 Links - Edition 6 (36939-90057)

Glossary
Q bit
Glossary
232232
Q bit Qualified bit. When set in DATA packets the Q
bit signifies that the packet's user data is a control
signal for the remote device, not a message for its
user.
QuickVal A software program that tests whether
Network Services are operating correctly between
nodes.
RDBS Remote Data Base Access. A network service
that allows users to access data bases on remote
nodes.
reachable network A network that can be
accessed (with additional internet hops possibly
required) by a particular gateway.
remote connect device Asynchronous device that
is connected to a DTC indirectly, using a modem and
telephone hook-up, or a PAD.
remote node A node on an internetwork other than
the node you are currently using or referring to.
retransmission count (N2) The maximum
number of times a frame will be retransmitted
following the expiration of the retransmission timer,
T1.
retransmission timer (T1) Length of time the
transmitter will wait for an acknowledgment from
the destination address before attempting to
retransmit the frame. When choosing this value,
factors like the line speed and maximum frame size
should be taken into account.
RFA Remote File Access. A network service that
allows users to access files and devices on remote
nodes.
router network See Point-to-Point.
routing The path that packets, or fragments of a
message, take through a network to reach a
destination node.
RPM Remote Process Management. A network
service that allows a process to programmatically
initiate and terminate other processes throughout a
network from any node on the network.
RS-232-C Electronic Industries Association (EIA)
level 1 protocol specification that defines electrical
circuit functions for 25 connector pins. HP provides
two implementations of this standard: a 3-pin
version for direct connections up to a distance of
15 meters (50 feet), and a version which makes use
of additional circuits and can be used for either
modem or direct connections.
RS-422 Electronic Industries Association (EIA) level
1 protocol specification implemented by HP in a
5-pin version which can be used for direct device
connection up to a distance of 1500 meters (4000
feet).
security string An alphanumeric character string
that functions as a password for dial links. The
security string is used by the dial IP protocol.
serial device Any device that is attached to and
communicates with a computer by means of a serial
transmission interface. Terminals, printers, and
plotters are among the devices that communicate
serially with HP 3000 Series 900 computers.
serial transmission Method of transferring data in
which characters are transmitted one bit at a time
and received one bit at a time in the order of
transmission. This transmission scheme is employed
by devices connected to the system via the DTC.
session-accepting device A terminal or personal
computer running in terminal-emulation mode that
is able to establish an interactive (conversational)
session with an HP 3000 computer. Also referred to
as a logon device.
shared dial A dial link that provides connection to
more than one remote system, although to only one
at a time.
shared-line access Feature that allows two or
more HP 3000 Series 900 hosts to use the same
DTC/X.25 Network Access card on a DTC to access
an X.25 network.
SIC Serial Interface Card. Card installed in the
front of the DTC that acts as an interface between a
corresponding connector card (CC) and the DTC’s
processor.
slaved device A device that shares the same DTC
port as another device and is connected to the other
device, referred to as its master, by a cable. The
actions of the slaved device are controlled by the
master device.