OSI/FTAM Configuration and Management Manual

Glossary
OSI/FTAM Configuration and Management Manual—421944-001
Glo ssary-10
Transmission Control Protocol/Internet Protocol
(TCP/IP)
Transmission Control Protocol/Internet Protocol (TCP/IP). A set of layered
communications protocols for connecting workstations and larger systems. See also
Tandem NonStop TCP/IP.
Transport entity. A process in the Transport Layer
that sends or receives a given transport
protocol data unit (PDU).
Transport Layer. Layer 4 in the Open Systems Interconnection (OSI) Reference Model
. This
layer provides reliable, transparent transfer of data between end systems and ensures that
the data arrives at the correct destination. It provides reliable data transfer independent
of the underlying network service provider (NSP) process.
transport protocol data unit (TPDU). See protocol data unit (PDU)
.
transport selector (TSEL). A logical address in the Transport Layer
through which transport
services are made available. A single TSEL can service one or more connections
simultaneously.
transport service access point (TSAP). A network-unique address in the Transport Layer
through which connections are established and maintained. Also called transport
address.
transport service data unit (TSDU). A unit of data used by transport peer entities to transfer
data.
transport service provider (TSP) process. A process in the Open Systems Interconnection
(OSI) end system that performs service and protocol functions for the Transport Layer
and for the Internet Protocol (IP) of the network service provider (NSP) process. TSP
processes are provided by the underlying Tandem OSI/TS subsystem.
ViewPoint. An extensible, interactive, console application for operators, provided as part of
Distributed Systems Management (DSM)
.
X.25 Access Method (X25AM). A Tandem product that implements, for wide area networks
(WANs), the services of the Network Layer
and layers below.
X.25 network. Any network or subnetwork linked using X.25 standards. X.25 standards are
International Telecommunications Union–Telecommunications (ITU–T) standards that
define packet-switching carrier communications in the Network Layer over wide area
networks (WANs).