OSI/MHS Configuration and Management Manual

OSI/MHS Configuration and Management Manual—424827-003
Glossary-21
environment, under control of a specified MHS manager. There can be more than one
OSI/MHS subsystem on a NonStop system.
OSI/MHS subvolume. The subvolume that contains all files required by an OSI/MHS
subsystem, such as executable object and configuration files. The MHS manager
must always reside in this subvolume, but some of the other executable files can
reside elsewhere, as defined by the MHS manager.
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. See also layer.
OSI services. The HP NonStop implementation of the OSI Reference Model. OSI services
consist of an OSI manager process and a number of subordinate protocol processes.
The protocol processes handle OSI protocols and provide layer services. The network
service provider, NSP, handles layers 1 through 3 and is provided by access methods
such as X25AM, PAM, and TLAM. The transport service provider, TSP, handles Layer
4 and is provided by OSI/TS. The TSP process also provides Layer 3 for LANs. The
session, presentation, and application services provider, TAPS, handles layers 5, 6,
and 7, and is provided by OSI/AS.
outbound communication. A communication sent to the X.400 network from a client. See
also inbound communication.
output queue. A queue for messages, probes, and reports that are outbound from the
gateway application to X.400.
P1-encoded object. The BER-encoded form of a P1 message. See also BER and P1
message.
P1 protocol. The X.400 message transfer protocol, which defines the transfer of messages
between two message transfer agents (MTAs).
P1 message. An X.400 message that consists of an envelope and its content. The envelope
contains delivery information; the content is the actual information that is to be
delivered to the recipient.
P2 protocol. The X.400 interpersonal message (IPM) user agent protocol, which defines the
format by which one user agent (UA) sends an interpersonal message (IPM) to one or
more other UAs.
P2 message. An X.400 message that consists of a heading followed by a series of data
blocks, called body parts. The heading contains the message originator, recipients,
and other service information. Each body part can contain a different form of data, and
messages can be nested within body parts.