Compaq OSI/APLMGR D43 TPDU transport protocol data unit. See PDU, transport selector. See TSEL

Glossary

also performs some management services in the DSM environment. See also NSP process and TSP process.

TAPS subdevice. A subdevice, maintained by OSI/AS, that enables communication between an FTAM initiator or responder and the TAPS process. See subdevice.

TeletexString. The character-string type of strings conforming to CCITT Recommendation T.61. These strings do not contain format effectors.

TLAM (Tandem LAN access method). A Compaq product that implements, for LANs, the services of the Data Link Layer and layers below.

TPDU (transport protocol data unit). See PDU.

trace file. The file in which the SCF trace facility collects trace information while a trace is in progress.

Transaction Application Language. See TAL.

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. See also abstract syntax.

transient error. An ISO-defined type of diagnostic error that may not recur if the sequence is repeated but does indicate the failure of the operation being performed. See also error type, informative message, and permanent error.

transition state. See state transition. transport address. See TSAP.

Transport Layer. Layer 4 in the OSI Reference Model. This layer provides reliable data transfer.

transport selector. See TSEL.

transport service access point. See TSAP. transport service provider. See TSP.

traversal. An ordering of the nodes in a tree such that each node occurs only once, and which is determined by an algorithm applicable to all possible trees.

tree. A connected hierarchical file structure in which each node is linked to other nodes by directed arcs in such a way that one node has no inbound arcs, and all other nodes have exactly one inbound arc. See also subtree.

TSAP (transport service access point). A network-unique address in the Transport Layer through which connections are established and maintained. Also called transport address.

TSEL (transport selector). A logical address in the Transport Layer through which transport services are made available.

TSP (transport service provider) process. A process in the Compaq OSI end system that performs service and protocol functions for the Transport Layer and for the internet

OSI/FTAM Responder Manual—425199-001

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