OSI/TS SCF Reference Manual

Glossary
OSI/TS SCF Reference Manual—424832-001
Glossary-12
token bus
local application. There are four session tokens; each is associated with a functional unit.
The availability of each token depends on which functional units are used on the
connection.
(2) In Distributed Systems Management (DSM)
terms, a distinguishable unit in a
Subsystem Programmatic Interface (SPI) message.
token bus. The IEEE 802.4 standard for the both Data Link Layer
(media access control
sublayer only) and Physical Layer of the Open Systems Interconnection (OSI) Reference
Model, which defines a token-passing bus access method for connections over LAN
networks.
transfer syntax. In the Presentation Layer
, the definition of the exact bit patterns to be used
to convey specified kinds of information in a communication.
Transmission Control Protocol/Internet Protocol (TCP/IP). A set of layered
communications protocols for connecting workstations and larger systems. See also
NonStop TCP/IP
.
transport address. See transport selector (TSEL)
.
transport classes. The International Standards Organization (ISO) standard for transport
protocol defines five different classes of transport protocols to meet varying user needs
for operation over different types of networks.
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
, but does, however, in the
CONS case, depend on the network service provider (NSP) process to provide the
network connection.
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