Configuring Systems for Terminals, Printers, and Other Serial Devices (32022-90051)
Glossary 265
Glossary
probe proxy server A node on
an IEEE 802.3 network that
possesses a network directory. A
probe proxy server can provide a
node with information about
other nodes on the same or other
networks of an internetwork.
profile A method of grouping
device connection specifications
and characteristics so that the set
of characteristics can be easily
associated with groups of like
devices. See also printer profile,
terminal profile.
program captive device See
programmatic device.
Programmable Serial
Interface PSI. A hardware card
that fits into the backplane of the
HP 3000 Series 900 computer. It
provides a physical layer
interface for NS Point-to-Point
3000/iX Links.
programmatic device A device
operating under control of a
program running on a computer.
Programmatic devices can be
used for input, output, or both,
depending on the device and how
it is opened by the controlling
program.
protocol A set of rules that
enables two or more data
processing entities to exchange
information. In networks,
protocols are the rules that
govern each layer of network
architecture. They define which
functions are to be performed and
how messages are to be
exchanged.
PSN Packet-Switching Network.
Any data communication network
in which data is disassembled
into packets at a source interface
and reassembled into a data
stream at a destination interface.
A public PSN offers the service to
any paying customer.
PSS Packet-Switching System.
The national public PSN of the
United Kingdom.
PVC Permanent Virtual Circuit.
A permanent logical association
between two physically separate
DTEs that does not require call
set-up or clearing procedures.
PXP See Packet Exchange
Protocol.
Q
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.
R
RDBA Remote Data Base Access.
A network service that allows
users to access data bases on
remote nodes.