OSI/FTAM Responder Manual

Glossary
OSI/FTAM Responder Manual—425199-001
Glossary-18
example, a default set of permitted actions that is always used for a specific document
type regardless of what is proposed. The responder implements the set of permitted
actions in some way that maps them onto the underlying real system.
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 the
Physical Layer include rules for the transmission of bits across the physical medium and
rules for connectors and wiring.
PID (process identifier). The combination of the central processing unit (CPU) number
and the process identification number (PIN) for a process running on the Compaq
NonStop Kernel.
port address. For X25AM lines, the logical port number used with the X.25 network;
for TLAM, the address used to communicate with a LAN controller.
PPDU (presentation PDU). See PDU.
presentation address. An unambiguous name used to identify a set of presentation
service access points (PSAPs) that are all located at a boundary between a Presentation
Layer implementation and an Application Layer implementation in the same open
system.
presentation context. The combination of an abstract syntax and a transfer syntax on a
Presentation Layer connection. In Compaq FTAM, you have programmatic control over
the choice of presentation context related to document types, but not over the required
abstract syntaxes associated with the protocol control information (PCI) for FTAM,
ACSE, and the Presentation Layer.
Presentation Layer. Layer 6 in the OSI Reference Model. This layer provides a means
to resolve the differences of varying data formats between systems of different vendors.
It transfers data in a system-independent manner, performing appropriate conversions at
each system as necessary.
presentation selector. See PSEL.
presentation service access point. See PSAP.
primary process. The currently operating process of a process pair on a Compaq
NonStop system. See backup process.
primitive. An abstract, implementation-dependent representation of an interaction
between a user of OSI services and a service provider. Examples of FTAM primitives
are an F-OPEN request, an F-P-ABORT indication, an F-CREATE response, and an
F-READ-ATTRIB confirm.
PrintableString. The character-string type of strings containing only printable
characters and the space character, as defined in ISO 8824. These strings do not contain
format effectors.
printing distributor. An EMS process that obtains formatted text for selected event
messages and distributes it to a file, a printer, or another display device.
priority. See execution priority.