OSI/MHS Configuration and Management Manual

OSI/MHS Configuration and Management Manual—424827-003
Glossary-23
subsystem implements, for LANs, the services of the Data Link Layer and layers
below. PAM replaces the LAN Access Method (TLAM) for G06 and later RVUs.
port address. For X25AM lines, the logical port number used to specify the address of the
connection to the X.25 network. For TLAM lines, the address used by TLAM to specify
the address of the connection to a LAN controller.
Presentation Layer. Layer 6 in the OSI Reference Model. This layer resolves 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.
primitive. See service.
printable string. An ordered set of characters that can include alphanumeric characters,
spaces, and any of the following symbols: ' ( ) + , - . / : ? This character set
corresponds to the repertoire of telex terminals and similar devices.
printing distributor. An EMS distributor process that obtains formatted text for select event
messages and distributes it to a printer or other display device, or to a file.
priority. In OSI/MHS, the order in which alternate routes are attempted. Priority values are
relative only to the other priorities for a particular MTA.
Also, a classification of an X.400 message as normal, urgent, or non-urgent. The
message priority is included, along with other delivery instructions, in the envelope of
an X.400 message and is a factor in the routing of messages through the X.400
network. The P2 protocol defines a parallel (but unrelated) concept of message
importance, which is intended to be meaningful to the recipient or the recipient UA.
private management domain. See PRMD.
PRMD (private management domain). An X.400 domain managed by a private
organization, such as a corporation. See also domain.
probe. An X.400 communication sent by an originator into the MTS to test the likelihood of
delivery of a message or report. It consists of an envelope and the description of the
actual content of the message or report. The envelope is similar to, but not the same
as, an envelope that would be used for an actual message or report.
process. A running entity that is managed by the operating system, as opposed to a
program, which is a collection of code and data. A process is a unique execution of a
program.