OSI/FTAM Configuration and Management Manual

Glossary
OSI/FTAM Configuration and Management Manual—421944-001
Glossary-6
Open Systems Interconnection (OSI) subsystem
Open Systems Interconnection (OSI) subsystem. One Open Systems Interconnection (OSI)
manager process controls one or more TAPS and TSP processes. The OSI manager
processes communicates with NSP processes but do not control them. The OSI manager,
TAPS, TSP, and NSP processes can be on the same or different nodes within the same
Expand network. See also Open Systems Interconnection (OSI)
and Open Systems
Interconnection (OSI) manager process.
OSI/AS. See Tandem OSI/AS
.
OSI/FTAM. See Tandem OSI/FTAM
.
OSI/TS. See Tandem OSI/TS
.
Physical Layer. Layer 1 in the Open Systems Interconnection (OSI) Reference Model
. This
layer establishes the actual physical connection between the network and the computer
equipment. Protocols at the Physical Layer include rules for the transmission of bits
across the physical medium and rules for connectors and wiring.
Port Access Method (PAM). A Tandem communications subsystem that provides an
independent interface to allow applications access to token-ring or Ethernet local area
networks (LANs) on Himalaya S-series servers. The PAM subsystem provides a port
interface that applications can use by making file-system procedure calls. The PAM
subsystem implements, for LANs, the services of the Data Link Layer
and layers below.
PAM replaces the Tandem LAN Access Method (TLAM) for G-series releases.
port address. For ViewPoint
lines, the logical port number used to specify the address of the
connection to the X.25 network. For the Tandem LAN Access Method (TLAM) (for
D-series releases) or the Port Access Method (PAM)
(for G-series releases) lines, the
address used by TLAM or PAM to specify the address of the connection to a local area
network (LAN) controller. Preferred binary encoding method.
Presentation Layer. Layer 6 in the Open Systems Interconnection (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 (PSEL). A logical address in the Presentation Layer
through which
presentation services are made available. A single PSEL can service one or more
connections simultaneously.
presentation service access point (PSAP). A network-unique, physical address in the
Presentation Layer
through which connections are established and maintained. Also
called presentation address.
protocol data unit (PDU). Information delivered as a unit between peer entities that contains
data and/or control and address information.
release token. One of the four types of Session Layer
tokens that are associated with
functional units.