OSI/AS SCF Reference Manual

Glossary
OSI/AS SCF Reference Manual—424121-001
Glossary-3
data-transfer phase
arrives at the next layer without any errors. OSI/TS is an example of an application that
uses the Data Link Layer.
data-transfer phase. The phase of an Open Systems Interconnection (OSI)
connection in
which data is transferred. This phase begins when the connection-establishment phase
is
completed. Compare connection-release phase
.
dialog unit. In the Session Layer
, the work carried out between two major synchronization
points chosen by the application.
Distributed Name Service (DNS). A part of Distributed Systems Management (DSM)
used
to simplify the management of objects in a NonStop system or an Expand network by
managing a distributed, and partially replicated, database of objects. DNS has both a
programmatic and an interactive interface.
Distributed Systems Management (DSM). A set of tools used to manage NonStop systems
and Expand networks. These tools include the ViewPoint
console application, the
Subsystem Control Facility (SCF) for data communications subsystems, the Subsystem
Programmatic Interface (SPI), the Event Management Service (EMS), the Distributed
Name Service (DNS), and token-oriented programmatic interfaces to the management
processes for various Compaq subsystems.
distributor. An Event Management Service (EMS)
process that distributes event messages
from event logs to requesting management applications, to console message
destinations, or to a collector
on another node.
DSC. See Dynamic System Configuration (DSC)
.
DSM. See Distributed Systems Management (DSM)
.
Dynamic System Configuration (DSC). For D4x-series only, a facility that allows system
managers to make online changes to the configuration of devices and controllers. Its
interactive utility program is called the Configuration Utility Program (COUP)
. DSC is
not used to configure Compaq OSI subsystem objects, but it can be used to configure the
underlying X.25 Access Method (X25AM)
and Tandem LAN Access Method (TLAM)
objects.
EMS. See Event Management Service (EMS)
.
end system. A host or user machine that contains all seven Open Systems Interconnection
(OSI) layers. An end system can communicate with another end system either directly or
through one or more intervening intermediate systems. Compaq systems function as end
systems only. See also intermediate system
.
entry. A type of object representing a routing table or directory entry in the Management
Information Base (MIB).
event. In Distributed Systems Management (DSM)
terms, a significant change in some
condition in the system or network. Events can be operational errors, notifications of
limits exceeded, requests for action needed, and so on.