TCP/IP Management Programming Manual

Glossary
HP NonStop TCP/IP Management Programming Manual—529636-001
Glossary-13
object-name template
communications line $X2502. An object typically has a name and a type known to the
controlling subsystem.
object-name template. In DSM, a name that stands for more than one object. Such a name
includes one or more wild-card characters, such as * and ?. See also wild-card
character.
object type. In DSM, the category of objects to which a specific object belongs: for
example, a specific disk file might have the object type FILE, and a specific terminal
might have the object type SU (subdevice). A subsystem identifies a set of object types
by the objects it manages. The SCF interfaces to Tandem data communications
subsystems use standard keywords to identify the types. The corresponding
programmatic interfaces have object-type numbers (represented by symbolic names
such as ZCOM-OBJ-SU) suitable for passing to the SPI SSINIT procedure.
open system. Any computer system that adheres to the OSI standards.
Open Systems Interconnection (OSI). A set of standards used for the interconnection of
heterogeneous computer systems, thus providing universal connectivity.
OSI. See Open Systems Interconnection (OSI).
OSI Reference Model. A communications architecture, adopted by the ISO in 1984, that
includes seven layers that define the functions involved in communications between
two systems, the services required to perform these functions, and the protocols
associated with these services.
packet. The unit of data sent across a packet switching network. While some Internet
literature uses it to refer specifically to data sent across a physical network, other
literature views the Internet as a packet switching network and describes IP datagrams
as packets.
Packet Internet Groper (PING). The name of a program used in the Internet to test the
reachability of destinations by sending them an ICMP echo request and waiting for a
reply. The term has survived the original program and is now used as a verb, as in
“please ping host A to see if it is alive.”
packet switching. A technique in which messages are broken into smaller units, called
packets, that can be individually addressed and routed through the network. The
receiving-end node ascertains whether all the packets are received and in the proper
sequence before forwarding the complete message to the addressee.
PDN. See Public Data Network (PDN).
physical interface (PIF). The hardware components that connect a system node to a
network.
physical layer. Layer 1 in the OSI Reference Model. This layer establishes the actual
physical connection between the network and the computer equipment. Protocols at