ACSE/Presentation and ROSE Interface Programmer's Guide

Glossary 105
Glossary
ODA Office Document
Architecture; a developing
standard that enables text,
graphics and facsimile, in different
document formats, to be moved
over a multivendor network.
OSI Open Systems
Interconnection; the name used to
describe a set of data
communications standards which
have been agreed upon at an
international level by national
standards bodies.
OSI Reference Model a
modular, seven-layer construct
that specifies how data will travel
among systems of a multivendor
network, as well as within a single
system.
Physical Layer Layer 1 of the
OSI model; enables the sending
and receiving of bits between
nodes on a network.
Presentation Address An
address made up of a P-selector, S-
selector and T-selector
(presentation, session, and
transport selectors) and one or
more NSAPs. Optionally, it can
include the application entity (AE)
title which is a unique name
identifying an OSI service such as
FTAM.
Presentation Layer Layer 6 of
the OSI model; where data are put
into usable form.
proprietary networking
networking that uses the products
and protocols of a single vendor.
protocol a formalized set of rules
by which computers communicate.
ROSE Remote Operations Service
Element. The OSI application
service element which manages
request/reply interactions.
SAP Service Access Point. A SAP
is a pipe between two OSI layers
such that an entity at layer n + 1
can obtain a set of services from
layer n.
Selector a sequence of octets
(bytes) used to identify a SAP.
Session Layer Layer 5 of the OSI
model; permits the setup of a
communications path along a
network and manages the
coordination between processes.
SNA Systems Network
Architecture; IBM's proprietary
networking formats, protocols and
procedures that are also a de facto
networking standard.