TCP/IP Configuration and Management Manual

Glossary
TCP/IP Configuration and Management Manual—427132-004
Glossary-13
PDN
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
the Physical Layer include rules for the transmission of bits across the physical
medium and rules for connectors and wiring.
PIF. See “physical interface (PIF).”
PING. See PING.
predefined value. A commonly used value—for instance, a value for a token or a field in a
token—that is given a name in a set of definition files.
process. A running entity that is managed by the operating system, as opposed to a
program, which is a collection of code and data. When a program is taken from a file
on a disk and run in a processor, the running entity is called a process.
programmatic command. In DSM, a command issued by a program rather than by a
human operator. Compare interactive command
.
protocol. A formal description of message formats and the rules two or more machines
must follow to exchange those messages. Protocols can describe low level details of
machine-to-machine interfaces (for example, the order in which the bits from a byte are
sent across a wire), or high-level exchanges between application programs (for
example, the way in which two programs transfer a file across the Internet). Most
protocols include both intuitive descriptions of the expected interactions as well as
more formal specifications using finite state-machine models.
Public Data Network (PDN). A network with data communications services available to any
subscriber.
Request for Comments. he name of a series of notes that contain surveys, measurements,
ideas, techniques, and observations, as well as proposed and accepted Internet
protocol standards. RFCs are edited but not referenced. They are available across the
Internet.
response. In DSM use, the information or confirmation supplied (as part of a response
message) to an application by a subsystem in response to a DSM command.
response message. An SPI message sent from a subsystem to an application program in
reaction to a command message. Compare
command message or event message.
response record. In DSM programmatic interfaces, a set of response tokens usually
describing the result when a command is performed on one object. Every response
record in a response from a subsystem contains a return token; a response record can