OSI/AS Configuration and Management Manual

Glossary
OSI/AS Configuration and Management Manual—424119-001
Glossary-8
Session Layer
Session Layer. Layer 5 in the Open Systems Interconnection (OSI) Reference Model. It
allows the setup and termination of and controls communication sessions between nodes
on the network.
session selector (SSEL). A logical address in the Session Layer
through which session
services are made available. A single SSEL can service one or more connections
simultaneously.
session service access point (SSAP). A network-unique address in the Session Layer
through
which connections are established and maintained.
SPI. See Subsystem Programmatic Interface (SPI)
.
SSEL. See session selector (SSEL)
.
SSID. See subsystem ID (SSID)
.
station group address. A media access control (MAC) address, common to the same type of
system (that is, intermediate systems or end systems), that is used by a system to
broadcast to all systems of the same type.
subdevice. A logical entity providing access to a physical entity (a communications line).
There may be one or many subdevices associated with a given line or process. Exactly
what constitutes a subdevice differs depending on the subsystem. A X.25 Access
Method (X25AM) subdevice corresponds to an X.25 network virtual circuit. Tandem
LAN Access Method (TLAM) subdevices are of several types: FSAPs, ports, services,
domains, workstations, windows, and gateways [for G06 and later releases, Port Access
Method (PAM) subdevices correspond to PAM ports].
subnetwork. One or more intermediate systems that provide relaying and through which end
open systems may establish network connections.
subsystem. In Distributed Systems Management (DSM)
, a program or set of processes that
manages a cohesive set of objects. Each subsystem has a process through which
applications can request services by issuing commands defined by that subsystem; in
some cases, this process is the entire subsystem. Many subsystems also have an
interactive interface.
Subsystem Control Facility (SCF). A Distributed Systems Management (DSM)
facility that
allows system managers to make online changes to the configuration of devices and
controllers. DSM is used to provide a common, interactive management interface for
configuring, controlling, and collecting information from Compaq data communications
products.
Subsystem Control Point (SCP). In Distributed Systems Management (DSM)
, the
management process for all Compaq data communications subsystems. Applications
using the Subsystem Programmatic Interface (SPI)
send all commands for data
communications subsystems to an instance of this process, which in turn sends the
commands on to the manager processes of the target subsystems. SCP also processes a