T

table
(1) An orderly arrangement of data in rows and columns that can contain numbers, text, or a combination of both. The system-recognized identifier for the object type is *TBL. See also conversion table.
(2) In COBOL, a set of logically consecutive data items that are defined in the Data Division with the OCCURS clause.
(3) In RPG, a series of elements with like characteristics. A table can be searched for a uniquely identified element, but elements in a table cannot be accessed by their position relative to other elements. Contrast with array.
(4) In DB2 UDB for AS/400, a named data object consisting of a specific number of columns and some unordered rows.

table designator
In DB2 UDB for AS/400, a column name qualifier that designates a specific object table.

table element
In COBOL, a data item that can be referred to in a table.

table file
In RPG, an input file that contains a table.

table-reference character (TRC)
(1) In Advanced Function Printing (AFP) support, an optional control character in line data. The TRC identifies the font used to print the record and can be used to select a font during printing.
(2) In a 3800 Printing Subsystem, a numeric character corresponding to the order in which the names for the character-arrangement table have been specified.

tables
Tables that store resources used in the CICS system.

tab stop
In VisualAge RPG, a control setting that determines if a control can be selected by using the tab key.

tachometer
A part that determines speed of rotation.

tag
(1) In UIM, the actual statements of the UIM tag language. Tags describe the actions, format, and data of the panel. Tags are used to define the formatting of help information.
(2) In OSI, a type designation that is associated with every ASN.1 type.

tag content
The text associated with a tag.

tail
In REXX, the part of a compound symbol that follows the stem. A tail can consist of constant symbols, simple symbols, and periods.

tailored document
In the OfficeVision program, a shell document to which variable data is added.

tangent
In the GDDM function, the single point at which a straight line meets a curve or surface.

tape cartridge
A case containing a reel of magnetic tape that can be put into a tape unit without stringing the tape between reels.

tape controller
A logic card located in some tape units that controls input/output tape devices and synchronizes their operation with the operation of the system as a whole.

tape drive
A device used to move the tape and read and write information on magnetic tapes.

tape file
A device file to support a tape device.

tape library
A device that includes a selection of cartridges in a common (secure) area within access of one or more automated removable media (ARM).

tape mark
A unique mark written on the tape to distinguish file boundaries.

tape reel
A round device on which magnetic tape is wound.

tape unit
The physical enclosure containing the tape drive.

tape volume
A single reel of magnetic tape.

target
(1) In advanced program-to-program communications, the program or system to which a request for processing is sent.
(2) In DDM, the remote system where the request for a file is sent.
(3) In SEU, a line command, such as B (Before) or A (After), that specifies the destination for other line commands such as C (Copy) or M (Move).
(4) In VisualAge RPG, a part that receives a target event from a source part whenever the state of the source part changes.

target data queue program
In Client Access, a series of AS/400 programs that receive requests for data manipulation from the source data queue program. Target data queue programs also send data and replies (to previous requests) to the source data queue program.

target directory
In VisualAge RPG, the directory in which the compiled VRPG application is stored.

target distributed data manager (TDDM)
In a distributed data management network, programming support that translates the DDM requests received from a source system into data management or SQL requests on the target (or remote) system. Contrast with source distributed data manager (SDDM).

target event
In VisualAge RPG, an event that a target part receives whenever the state of a source part changes.

target folder
In VisualAge RPG, the folder where the application (composite project) will be created.

target group
In the Application Development Manager feature of theApplication Development ToolSet licensed program, the final group to which a part can be promoted.

target program
(1) In communications, the program that is started on the remote system at the request of the source system. Contrast with source program.
(2) In display station pass-through, a program that runs on the remote system.
(3) In VisualAge RPG, the object to be built by the project, such as a Dynamic Link Library (DLL).

target recovery time
The amount of time estimated by the system that it will need to recover access paths during an initial program load (IPL) after an abnormal system end. Actual performance may range around the target.

target release
(1) The release of the operating system on which a user intends to use an object being created, or intends to restore or use an existing object.
(2) In upgrades, the VxRxMx of software that is to be installed.

target system
(1) The system that receives a request from another system to establish communications.
(2) In a distributed data management (DDM) network, the system that receives a request from an application program on another system to use one or more files located on the target system. Contrast with source system.
(3) In upgrades, the planned hardware configuration and software level which will exist when the upgrade is completed.
(4) The system that receives information in a network of systems that exchange objects and data. Contrast with source system.

target table
In DataPropagator Relational, the table to which data is copied.

tariff
The fee the packet-switching data network charges a user for sending data. The tariff is usually based on the number of packets sent over the network.

task control
A CICS facility that controls resources at task syncpoint and when a normal or abnormal end occurs.

task swapper
A function, introduced with DOS 5.00, that allows the user to switch from one application to another without ending either application. With the task swapper function, only one application is active at any time. The active program is the application that is currently running; all other applications are suspended until the user switches to that application.

TB
See terabyte (TB).

TC
See test control (TC).

TCAM
See telecommunications access method (TCAM).

TCB
See Trusted Computing Base (TCB).

TCP
See Transmission Control Protocol (TCP).

TCP/IP
See Transmission Control Protocol/Internet Protocol (TCP/IP).

TCP/IP Connectivity Utilities
The IBM licensed program that provides a collective set of industrial communications protocols to support connectivity functions for both local and wide area networks.

TCS
See terminal control system entry (TCS).

TCT
See Terminal Control Table (TCT).

TCTUA
See Terminal Control Table User Area (TCTUA).

TD
See transient data (TD).

TDDM
See target distributed data manager (TDDM).

TDF
See time differential factor (TDF).

TDLC
See twinaxial data link control (TDLC).

TE
See terminal equipment (TE).

technical information exchange (TIE)
A part of the electronic customer support function that allows a user to send files to and receive files from a remote support system, and to search for information on a remote support system. The files are sent and received through a remote support network.

technology-independent machine interface (TIMI)
The lowest visible architectural layer of AS/400. TIMI defines the high-level machine instruction set and application programming interface that is independent of the underlying implementation. This allows the underlying hardware and Licensed Internal Code to evolve over time to take advantage of technology advances without affecting the user-level interface.

TEI
See terminal end-point identifier (TEI).

telecommunications
(1) The transmission of control signals and information between two or more locations, such as by telegraph, radio, or television.
(2) The transmission of data between computer systems over telecommunications lines and between a computer system and remote devices.

telecommunications access method (TCAM)
A 370-type access method used to transfer data between main storage and terminals (local or remote) on an AS/400 system.

Telecommunication Standardization Sector (ITU-T)
The Telecommunication Standardization Sector (ITU-T). Formerly known as the International Telegraph and Telephone Consultative Committee (CCITT). As of March 1, 1993, recommendations from this group will be known as ITU-T Recommendations. Recommendations made before March 1, 1993, will continue to be known as CCITT Recommendations.

telephone call state
In telephony, the condition of a telephone call that reflects what the past action on that call has been and what the next set of actions may be.

telephony
The use or operation of systems for the transmission of voice or data communications between separate points.

Telnet
In TCP/IP, an application protocol that allows a user at one site to access a remote system as if the user's display station were locally attached. Telnet uses the Transmission Control Protocol/Internet Protocol as the underlying protocol.

template
(1) A pattern to help the user identify the location of keys on a keyboard, functions assigned to keys on a keyboard, or switches and lights on a control panel.
(2) A special object used to create new objects of the same type. The newly created object has the same characteristics as the template.
(3) In REXX, a guide that allows strings to be parsed by words (delimited by blanks), by explicit matching of strings, or by specifying numeric positions.

temporary group
A list of existing calendars used to schedule items for a group of users in one step. The list can be used in the current session only, after which the list is deleted.

temporary library
A library that is automatically created for each job to contain temporary objects that are created by the system for that job. The objects in the temporary library are deleted when the job ends. The system name for temporary library is QTEMP.

temporary objects
Objects, such as data paths or compiler work areas, that are automatically deleted by the system when the operating system is loaded.

temporary storage (TS)
The CICS facility that allows application programs to store data in a temporary storage queue for later retrieval.

temporary-text-delay (TTD) character
The BSC transmission control character that tells the receiving station that there is a temporary delay in sending the data.

tentative
In the OfficeVision calendar function, pertaining to an event that is still not decided or not confirmed. A person who has authority to someone else's calendar can schedule only tentative events on that calendar.

terabyte (TB)
1 099 511 627 776 bytes. On AS/400, a terabyte is represented by the value, *MAX1TB, which is the maximum size of auxiliary storage that is allowed for an access path associated with a file.

teraspace
A type of temporary space that has a much larger capacity than other types of space. Teraspace storage can be used for dynamic storage allocations.

term
A string, symbol, or function call contained within a REXX expression.

terminal adapter
A device that connects a computer to an external digital communications line such as an integrated services digital network (ISDN) line.

terminal control
In CICS, a facility that handles addressing, and transmission error detection and correction for terminals (displays and printers) associated with the local CICS system. It also handles the intercommunication data queue used by CICS.

terminal control system entry (TCS)
A table defining the connections between CICS systems.

Terminal Control Table (TCT)
A table describing the terminals and logical units within a CICS network.

Terminal Control Table User Area (TCTUA)
An area used to pass information between application programs, but only if the same terminal is associated with the application programs involved.

terminal end-point identifier (TEI)
A number to identify the end point to the ISDN. Normally, assignment of the TEI can be done automatically by the ISDN.

terminal equipment (TE)
In an ISDN, data terminal equipment (DTE) that provides the function necessary for the operation of the access protocols by the user. See also terminal equipment 1 (TE1) and terminal equipment 2 (TE2).

terminal equipment 1 (TE1)
Data terminal equipment (DTE) with integrated ISDN support. In an ISDN, the AS/400 system is a TE1. See also terminal equipment 2 (TE2).

terminal equipment 2 (TE2)
Data terminal equipment (DTE) without an ISDN interface. To communicate with other equipment through an ISDN, this equipment must have the protocol converted to one that can be recognized by the network. For example, a 7820 ISDN terminal adapter may be used. See also terminal equipment 1 (TE1).

terminating plug
A part that ends the cable path on a computer system. The terminating plug is attached to the last disk, diskette, or tape unit in a series.

test
In communications, a data link command or response used to perform a basic test of the station-to-station link connection.

test condition
A statement that, when taken as a whole, may be either true or false, depending on the circumstances existing at the time the expression is evaluated.

test control (TC)
A signal sent by the data terminal equipment (DTE) to the attached data-circuit terminating equipment (DCE) to signal a testing mode.

test library
A user-defined library used for debugging operations that does not contain objects needed for normal processing. Contrast with production library.

test value
A value used to compare for a specified condition.

text attribute
In the GDDM function, characteristics of chart information, such as the color or type style.

text box
In Client Access for Windows, a box within a dialog box into which a user can type information. The text box may be empty or may contain default information when the dialog box first appears.

text index entry
An entry for a document in the text search index database. The text index entry is used by the system to locate documents when doing a text search.

text instruction
In the OfficeVision program, an abbreviated command, preceded by an instruction character, that produces a specified arrangement such as a numbered list of information on a page, in a file, or on a display when the document is processed.

text profile
In the OfficeVision program, a description of formatting and editing options for creating a document.

text search
In the OfficeVision program, a type of search that allows the user to find documents that contain one or more phrases within the document content.

text search index database
The database files used by text search services for storing the significant words of documents. These database files are used when a user requests a search of the document library for one or more phrases.

text search services
The system support that lets office users add, delete, and search for documents in the text search index database. See also text search and text search index database.

text stream
In the C language, an ordered sequence of characters where each sequence or line is ended with a new line control sequence and consists of zero or more characters.

text transparency
In BSC, a method of sending and receiving data containing any or all of the 256 character combinations in EBCDIC in specific bit patterns, including transmission control characters. Transmission control characters sent in the data are treated as specific bit patterns, unless they are preceded by the DLE control character.

textual data
The collective term for menus, displays, lists, prompts, options, online help information, and messages. See also online information.

TE1
See terminal equipment 1 (TE1).

TE2
See terminal equipment 2 (TE2).

TFTP
See Trivial File Transfer Protocol (TFTP).

TG
See transmission group (TG).

TH
See transmission header (TH).

third-party plug-in
In Operations Navigator, the support that allows users to install software from different vendors.

thousands separator
The character (comma in the United States) placed every third number starting left of the decimal point. For example, three thousands separators are used in the number: 641,322,974,821.

thread
(1) In the Distributed Computing Environment (DCE), a single sequential flow of control within a process.
(2) In the Integrated Language Environment (ILE), the basic line of the running of a program.
(3) A stream of computer instructions that is in control of a process. A multithread process begins with one stream of instructions (one thread) and may later create other instruction streams to perform tasks.
(4) In the OS/2 operating system, the smallest unit of operation to be performed within a process.

thread-capable
Pertaining to the ability to create threads.

thread handle
In DCE Remote Procedure Call (RPC), a data item that enables threads to share a storage management environment.

thread ID
The unique integral number that can be used to identify a thread. Thread ID is sometimes used to describe the pthread_t data type that represents the abstraction to a thread.

thread local storage
See thread-specific storage.

thread private storage
See thread-specific storage.

threadsafe
(1) A function, macro, or operating system service that can be called from multiple threads in a process at the same time. A thread that cannot be called from multiple threads is referred to as thread unsafe.
(2) A conditional form of thread safety.

thread-specific storage
Storage that is not shared among threads, but can be accessed by all functions within that thread. In the industry, also called thread private storage, thread local storage, or TLS.

Threads Service
A Distributed Computing Environment (DCE) component that supports the creation, management, and synchronization of multiple threads within a single process.

threshold
(1) A level set in the system at which a message is sent or an error-handling program is called. For example, in a user auxiliary storage pool, the user can set the threshold level in the system values, and the system notifies the system operator when that level is reached.
(2) In OSI, a user-specified value that determines the frequency with which events will be reported. For example, if a certain error threshold is set at 10, the error will not be reported until the tenth occurrence of the error.

threshold analysis
In Backup Recovery and Media Services, the comparison of actual media statistics to standard industry statistics for that media.

threshold event
In OSI, an event that occurs when a counter has reached its user-specified threshold. OSI Communications Subsystem logs threshold events and generates messages to the operator about these events.

threshold value
In the capacity planning tool, a value used as a general guide for optimal resource utilization. If resource utilization is above the threshold value, the resource performance may be unacceptable. Threshold values are also available for the rate of synchronous reads in the machine pool and for the sum of all pools. Contrast with guideline value.

throughput
(1) The measure of the amount of work performed by a computer over a period of time, for example, number of jobs per day.
(2) In data communications, the total traffic between stations over a period of time.

throughput class negotiation
(1) In X.25, a packet-switching data network optional facility that allows the data terminal equipment (DTE) to negotiate the speed at which its packets travel through the packet-switching data network. See also optional user facilities.
(2) In OSI, a network layer facility that selects the speed with which data transmission requests are to be handled.

thunking
In Client Access, the process that occurs when a 32-bit application calls a 32-bit application programming interface that is implemented by a 16-bit component of the system.

tick
In Business Graphics Utility, a reference point on either the vertical or horizontal axis of some chart types that represents the location of specified data values. See also major tick and minor tick.

ticket
In DCE Security, an application-transparent mechanism that transmits the identity of an initiating principal to its target. See privilege ticket, service ticket, simple ticket, and ticket-granting ticket.

ticket-granting ticket
In DCE Security, a ticket that allows access to the ticket granting service. See ticket simple ticket, privilege ticket, and service ticket.

TIE
See technical information exchange (TIE).

time
A three-part value or data type that designates a time of day in hours, minutes, and seconds.

time differential factor (TDF)
In the DCE Distributed Time Service (DTS), the difference between coordinated universal time (UTC) and the time in a particular time zone.

time duration
A decimal number that represents a number of hours, minutes, and seconds.

time format
In the OfficeVision program, a calendar value that identifies whether items are scheduled according to a 12-hour clock or a 24-hour clock.

time-independent messaging
In MQSeries, a method of communication between programs in which the requesting program proceeds with its own processing without waiting for a reply to its request. Contrast with synchronous messaging.

timemark
A specific period of time that is allowed by the Telnet server to verify that a connection is still active.

timeout
(1) An event that occurs at the end of a predetermined period of time that began at the occurrence of another specified event.
(2) A time interval that is allotted for certain operations to occur, for example, a response to polling or addressing before system operation is interrupted and must be restarted.

time-out period
In the Distributed Computing Environment (DCE), the amount of time in seconds that the Control Task waits for a daemon to initialize successfully. If this time elapses and the daemon does not indicate to the Control Task that is has successfully initialized, the daemon's state is deemed to be unknown.

time provider interface (TPI)
In the DCE Distributed Time Service (DTS), an interface between the DTS server and external time provider process.

time provider program
In the DCE Distributed Time Service (DTS), an application that functions as a time provider.

time provider (TP)
In the DCE Distributed Time Service (DTS), a process that queries Universal Coordinated Time (UTC) from a hardware device and provides it to the server.

timer-related event
A CICS interval control function that is used to support events that are delayed, suspended, or restarted after a time interval.

times authority
In the OfficeVision calendar function, the authority that allows the user to display the calendar name, description, and the times that are scheduled on another user's calendar.

time-sharing
Sharing computer time and resources.

time-sharing option
An operation on the System/370 operating system that provides interactive processing time for remote terminals.

time slice
The amount of processor time (specified in milliseconds) allowed for a job before other waiting jobs of equal priority are allowed to process data.

time slicing
In the Distributed Computing Environment (DCE), a mechanism by which running threads are preempted at fixed intervals. This ensures that every thread is allowed time to be run.

time stamp
(1) To apply the current system time.
(2) The value of an object that indicates the system time at some critical point in the object's history.
(3) In Query, the identification of the day and time a query report is created, which Query automatically provides on each report.

timestamp
In AS/400 database support, a seven-part value or data type that consists of a date and time, expressed in years, months, days, hours, minutes, seconds, and microseconds.

timestamp duration
A decimal number that represents a number of years, months, days, hours, minutes, seconds, and microseconds.

time to live
The time interval in seconds that an entry can exist in the cache before the name server discards it.

TIMI
See technology-independent machine interface (TIMI).

title
In OSI, a permanent identifier for an object.

title bar
The area at the top of each window that contains the system-menu symbol or the name of the window. In Client Access for Windows, the title bar may also contains a Control-menu box and the maximize and minimize buttons.

TLI
See transport layer interface (TLI).

TLS
See thread-specific storage.

toggle
(1) Pertaining to a switching device, such as a toggle key on a keyboard, that allows a user to switch between two types of operations.
(2) To switch between two modes; for example, on a personal computer connected to a network, to switch between the data entry and command entry modes or between stand-alone operation and device emulation.

token
(1) A predefined message or character pattern that gives the receiver of the token the permission to transmit information.
(2) In OSI, an attribute of a connection. The token is dynamically assigned to one session-service user at a time to permit certain services to be called. Tokens are a session layer concept. (I) See also data token, synchronize/minor token, major/activity token, and release token.
(3) The unit of low-level syntax from which REXX clauses are built. Tokens include literal strings, operator characters, and special characters.
(4) In CoOperative Development Environment/400, a character string in a specific format that has some defined significance in a programming language.
(5) In SQL, any single keyword, user-supplied word, or arithmetic or comparison operator. See delimiter token and ordinary token.

token highlighting
A function of CoOperative Development Environment/400 that allows a user to view different programming language tokens in different colors or type styles. See also token.

token-ring network
A local area network that sends data in one direction throughout a specified number of locations by using the symbol of authority for control of the transmission line, called a token, to allow any sending station in the network (ring) to send data when the token arrives at that location.

token type
In CoOperative Development Environment/400, a token or set of tokens having a similar characteristic or function, and assigned the same display attributes by the CoOperative Development Environment/400 program.

tool bar
In VisualAge RPG, a menu that contains one or more graphical choices representing actions a user can perform using a pointing device.

topic
In dynamic data exchange (DDE), the data that is to be exchanged within a DDE conversation.

top-level pointer
In DCE Remote Procedure Call (RPC), a pointer parameter that in a chain of pointers is the only member that is not the referent of any other pointer.

topology
(1) The relationship of the links and nodes of a network.
Note:The synonym for topology is configuration. The term is above the 16th-grade reading level. See also network chart in the IBM Dictionary of Computing.
(2) In communications, the physical and logical arrangement of nodes in a network.

topology database
(1) The representation of the current topology of the intermediate routing portion of the APPN network. The network topology database contains entries for network nodes and the transmission groups interconnecting them. Each entry describes the current characteristics of the node or transmission group that it represents. The topology database is used to determine the preferred session route between two end nodes for a given class of service.
(2) In Managed System Services, a set of database files that contain topology information and general system information for nodes throughout the network.

topology manager
A function of the Managed System Services program that is responsible for collecting topology information from nodes and clients in the network. The topology manager can reside on any system in the network; however, this system is most likely to be the central site system.

total accumulator
In DFU, a storage area where final totals for a field are kept. Contrast with batch accumulator.

total record
In RPG, an output record written after a group of detail records. Total records generally contain data that is the result of calculations performed on the information in a group of detail records. Contrast with detail record.

total time
The part of the RPG program cycle in which calculation and output operations specified for a group of records are done. Contrast with detail time.

tower
In the DCE Cell Directory Service (CDS), a set of physical address and protocol information for a particular server.

TP
(1) See transaction program (TP).
(2) For the Distributed Computing Environment (DCE), see time provider.

TPDU
See transport-layer protocol data unit (TPDU).

TPI
See time provider interface (TPI).

TPN
See transaction program name (TPN).

TP server
In the DCE Distributed Time Service (DTS), a server connected to a time provider (TP).

trace
(1) A debugging aid for system programmers and application programmers. It produces trace entries at set system points or in response to trace commands.
(2) In REXX, a means of tracking the interpretation of a program. Tracing is primarily used for debugging.

track
A circular path on the surface of a disk or diskette on which information is magnetically recorded and from which recorded information is read.

Traditional Chinese
The Chinese character set expressed in traditional form. Traditional Chinese characters are used in Taiwan, Hong Kong, and some other parts of the world.

Traditional Chinese double-byte character set
An IBM-defined DBCS for Traditional Chinese, consisting of Traditional Chinese non-Chinese set, primary set, secondary set, and up to 2,632 user-definable characters.

Traditional Chinese non-Chinese character set
A subset of the Traditional Chinese DBCS, consisting of non-Chinese characters, such as Greek, Russian, Roman numeric, alphanumeric and related symbols, Katakana, Hiragana, special symbols and Chinese phonetic symbols. There are 675 characters in this set.

Traditional Chinese primary character set
A subset of the Traditional Chinese DBCS, consisting of commonly used Chinese characters. There are 5,401 characters in this set.

Traditional Chinese secondary character set
A subset of the Traditional Chinese DBCS, consisting of less commonly used Chinese characters. There are 7,652 characters in this set.

transaction
(1) An item of business, for example, the handling of customer orders and customer billing.
(2) In CICS, a four-character code (called a tranid) that is recognized by CICS.
(3) In the Distributed Computing Environment (DCE), a unit of processing consisting of one or more application programs that is initiated by a single request, often from a terminal.
(4) In the Integrated Language Environment (ILE), a group of individual changes to objects on the system that should appear as a single atomic change to the user.
(5) In communications, an exchange between a program on a local system and a program on a remote system that accomplishes a particular action or result. See also conversation and session.
(6) In performance, a unit of work used to express the throughput of a workload or to request the estimated response time. An interactive transaction is the work done by the system when the Enter key or a function key is pressed. A noninteractive transaction is defined in terms of resource activity used by the noninteractive jobs.
(7) In DB2 UDB for AS/400, the work that occurs between begin unit of work and commit or rollback. A transaction defines the set of operations that is part of an integral set.

transaction code
For the IMS subsystem, the first one to eight characters of the first segment of a message sent to IMS/VS. The transaction code identifies the application program for which the message is intended.

transaction consistent
In DataPropagator Relational, a table that includes only committed changes.

transaction dump
In CICS, a formatted dump for the program active at the time the dump was requested. A transaction dump indicates where the error occurred within the program. See also dump.

transaction file
(1) A file containing data, such as customer orders, that is usually used only with a master file.
(2) In COBOL, an input-output file used to communicate with display stations and ICF sessions.

transaction program name (TPN)
The name by which each program participating in an LU 6.2 conversation is known. Normally, the initiator of a connection identifies the name of the program it connects to at the other LU. When used in conjunction with an LU name, a TPN identifies a specific transaction program in the network.

transaction program network
The hierarchical structure of user or system transaction programs communicating at a synchronization level of none, confirm, or commit. When the synchronization level is commit, the transaction programs communicate over protected conversations using the two-phase commit protocol. In this case, the hierarchy consists of an initiator, optionally one or more cascaded initiators, and agents.

transaction program (TP)
(1) A user-supplied application program for processing data received by the AS/400 system from a finance device.
(2) A program that processes transactions in an SNA network. The two kinds of transaction programs are application transaction programs and service transaction programs.

transaction routing
A CICS facility that provides support for inbound and outbound terminal requests from another CICS system connected by an advanced program-to-program communications (APPC) link.

transceiver
In communications, the device that connects the transceiver cable to the Ethernet coaxial cable. The transceiver is used to transmit and receive data.

transceiver cable
In communications, the cable along with its connectors that connects the input/output adapter to the transceiver.

transfer mode
Aspects covering transmission, multiplexing, and switching in a communications network.

transfer request
In Client Access, a description of the file you want to transfer to your personal computer from the AS/400 system or from your personal computer to the AS/400 system.

transfer syntax
(1) In DCE Remote Procedure Call (RPC), a set of encoding rules used for transmitting data over a network and for converting application data to and from different local data representations. See also Network Data Representation.
(2) In OSI, a set of rules for the representation of user information while it is in transit between presentation layer entities. The transfer syntax is usually derived from the abstract syntax by use of encoding rules. Contrast with abstract syntax.

transform
(1) To change the composition of a data stream (AFP) to perform the same functions in a different data stream (ASCII).
(2) In a Virtual Private Network (VPN), a collection of authentication algorithms, Diffie-Hellman groups, and encryption algorithms that are used during both phases of negotiation.

transformer
A device that converts power from one circuit to another at the same frequency, but at a changed voltage and current.

transform service
A function of the OS/400 operating system that converts PostScript Level 1 spooled files to output. This output can be printed on either IBM Advanced Function printers (OS/400 system printers) or Hewlett Packard Printer Control Language printers (commonly used PC printers).

transient data (TD)
A CICS facility that provides the user with the ability to read and write data in sequential queues.

transient error
In OSI, an error that occurs once or at unpredictable intervals--for example, network congestion. Contrast with permanent error.

transient event
In OSI, an event that indicates the occurrence of an intermittent error or an error that can be recovered through retry. Transient events are logged but do not result in messages to the operator. Contrast with permanent event.

transit delay processing
In OSI, an X.25 quality-of-service function that keeps track of delays that data encounters on the way to its destination. Any node that receives a call packet can reject it if the transit delay exceeds the maximum specified by the sender.

translator
An OS/400 component that performs the final step in a program or module compilation. In the Integrated Language Environment (ILE) model, this is called the optimizing translator.

transmission control characters
In data communications, special characters that are included in a message to control communications over a data link. For example, the sending station and the receiving station use transmission control characters to exchange information; the receiving station uses transmission control characters to indicate errors in data it receives.

transmission control layer
In SNA, the layer within a half-session that synchronizes and controls the speed of session-level data traffic, checks sequence numbers of requests, and enciphers and deciphers end-user data.

Transmission Control Protocol/Internet Protocol (TCP/IP)
(1) A set of communications protocols that support peer-to-peer connectivity functions for both local and wide area networks.
(2) The primary communications protocol that is used on the Internet. TCP/IP could also be used on an internal network.

Transmission Control Protocol (TCP)
In TCP/IP, a host-to-host protocol that provides transmission in an internet environment. TCP assumes Internet Protocol (IP) is the underlying protocol.

transmission executive
A part of the DSNX/PC licensed program that runs on the personal computer to control and handle requests and to create responses for DSNX.

transmission group (TG)
In SNA, a group of links between directly attached nodes appearing as a single logical link for routing messages. A transmission group may consist of one or more SDLC links (parallel links) or of a single System/370 channel. For type 2.1 nodes in AS/400 networks, a transmission group can only be a single-link connection.

transmission header (TH)
In SNA, control information, optionally followed by a basic information unit or a basic information unit segment, that is created and used by path control to route messages within the network.

transmission medium
In communications, the physical path between transmitters and receivers in a communications network, such as an Ethernet bus or a token ring.

transmission queue
In MQSeries, a local queue on which prepared messages destined for a remote queue manager are temporarily stored.

transmission services profile
In SNA, specified in a request to start a session. Each defined transmission services profile is identified by a number. Abbreviated TS profile.

transmission services (TS)
A switched, nonswitched, or packet-switched communications line provided by a vendor.

transmitted type
In DCE Remote Procedure Call (RPC), for data types with the Interface Definition Language (IDL) transmit_as attribute, the data type that stubs pass over the network. See presented type.

transparency
(1) A picture or text on an acetate sheet designed to be viewed by light shining through it.
(2) In asynchronous communications, a method of hiding certain ASCII control characters from modems or asynchronous devices.
(3) For BSC, see transparent text mode.

transparent data
Data that can contain any hexadecimal value.

transparent text mode
In binary synchronous communications, a method of transmission in which only transmission control characters preceded by the DLE control character are processed as transmission control characters.

transport class negotiation
In OSI, the process by which the peer application entities decide the Transport Layer class to use on an association.

transport class 0
In OSI, the simplest of five classes of service (0-4) or protocols defined in the transport layer. (I)

transport class 2
In OSI, the transport layer class that provides an intermediate level of service.

transport class 4
In OSI, the most complex of five classes of service (0-4) or protocols defined in the transport layer. (I)

transport independence
In DCE Remote Procedure Call (RPC), the capability, without changing application code, to use any transport protocol that both the client and the server systems support, while guaranteeing the same call semantics. See transport layer and transport protocol.

transport layer
In OSI architecture, the layer that provides services for flow control and recovery between open systems with a predictable quality of service. (T)

transport layer interface (TLI)
In the Distributed Computing Environment (DCE), an interface to the transport layer of the OSI model, designed on the ISO transport service definition. See also transport layer.

transport-layer protocol data unit (TPDU)
In OSI, a protocol data unit in the transport layer. (I)

transport-layer service access point (TSAP)
In OSI, a service access point in the transport layer. (I)

transport-layer service data unit (TSDU)
In OSI, a unit of data transferred between the session layer and the transport layer.

transport mode
In the OSI Communications Subsystem licensed program, a set of values that determine the transport layer functions to be used on an association. See also transport mode name.

transport mode name
In OSI, the name of a transport mode to be used for an association. The network administrator specifies the transport mode name on an application mode. See also transport mode.

transport protocol
A specification of the rules that govern the exchange of information between components of a transport network. For example, User Datagram Protocol (UDP) is a transport protocol.

trap
(1) An unsolicited event generated by an agent and forwarded to a manager. Traps inform the manager of changes that occur in the network.
(2) In REXX, to recognize that a currently enabled condition occurred and to perform the CALL or SIGNAL instruction specified when the condition trap was enabled.

TRC
See table-reference character (TRC).

tree view
In VisualAge RPG, a way of displaying the contents of an object in a hierarchical fashion.

T reference point
In Performance Tools, the interface between network termination 2 (NT2) and network termination 1 (NT1). See also S reference point and S/T interface.

tributary station
In data communications, a secondary device on a multipoint line.

trigger
A set of actions that are run automatically whenever a specified change statement is issued to a specified table or file. Triggers are often used to enforce business rules, such as authority protection.

trigger action
A set of actions (high-level language statements, SQL statements, or AS/400 utilities) that are performed automatically when a specified change operation (trigger event) occurs on a specified table or file. See trigger and trigger event.

trigger event
(1) A change operation that calls the trigger action to be run. The trigger event can be an insert, update, or delete operation in any high-level language. See trigger, trigger action, and trigger event.
(2) In MQSeries, an event, such as a message arriving on a queue, that causes a queue manager to create a trigger message on an initiation queue.

triggering
In MQSeries, a facility that allows a queue manager to start an application automatically when predetermined conditions on a queue are satisfied.

trigger level
In CICS, the number of requests for output to a CICS transient data queue that must be reached before automatic transaction initiation occurs.

trigger message
In MQSeries, a message that contains information about the program that a trigger monitor is to start.

trigger monitor
In MQSeries, a continuously running application that serves one or more initiation queues. When a trigger message arrives on an initiation queue, the trigger monitor retrieves the message. It uses the information in the trigger message to start a process that serves the queue on which a trigger event occurred.

trigger point
In REXX, a threshold or boundary limit used in the REXX FORMAT function.

trigger program
A program that contains a set of trigger actions. See trigger and trigger action.

trigger time
The time the trigger action runs before or after the trigger event operates. See trigger, trigger action, and trigger event.

trigraph
In DB2 UDB for AS/400, a sequence of 3 characters entered into a C-language source file to create a character from the C-language character set that is not available on certain keyboards. For example, the characters ??( are interpreted by the compiler as a left bracket, [.

trimming
To remove a list entry from the end of a list opposite from the end where the new entry was added.

triplet
A length byte, a type byte, and one or more parameter-value bytes in a Formatted Data Object Content Architecture (FD:OCA) descriptor.

Trivial File Transfer Protocol (TFTP)
In the Internet suite of protocols, a protocol that transfers files between hosts.

TRLAN
Abbreviation in the commands, parameters, and options for IBM Token-Ring Network. See also token-ring network.

truncate
(1) To cut off data that cannot be printed or displayed in the line width specified or available. Contrast with fold.
(2) To cut off data that does not fit in the specified field length in a field definition.

trunk
In telephony, circuits that connect two switching systems, as opposed to connecting a customer line to a switching system.

trunk line
A telecommunications line that links a private telecommunications system to a public switched network.

trusted
Pertaining to the control of a security policy.

Trusted Computing Base (TCB)
The term used by the U.S. Department of Defense to describe the combination of hardware and software in a computer system that enforces a unified security policy. See also C2.

trusted root
In secure communication, the public key and associated Distinguished Name of a certificate authority.

trusted system
A system in a network over which you have control of security. A trusted system can directly communicate only with other systems in the network.

trust peer
In the Distributed Computing Environment (DCE), one side of a cross-registration that enables two cells to have peer trust. See peer trust.

TS
See transmission services (TS) or temporary storage (TS).

TSAP
See transport-layer service access point (TSAP).

TSAP selector
In OSI, an external identifier for a service access point at the Transport Layer. The TSAP selector is part of a presentation address.

TSDU
See transport-layer service data unit (TSDU).

TSO
See time-sharing option.

TTD
See temporary-text-delay (TTD) character.

tuning parameters table
In DataPropagator Relational, a table at the data server that contains timing information used by the change capture program. The information includes how long to keep rows in the change data table, how long the time delay can be between changes to the DB2 UDB log and the capture of those changes by the change-capture program.

tunnel
An L2TP access concentrator (LAC)-L2TP network server (LNS) pair. A tunnel carries Point-to-Point Protocol (PPP) datagrams between the LAC and the LNS. There may be many sessions in a single tunnel. A control connection that operates in the tunnel controls the establishment, release, and maintenance of sessions and the tunnel itself.

turnaround
In communications, pertaining to changing a communications line from being able to send to being able to receive, or from being able to receive to being able to send.

turnaround time
In communications, the time required to reverse the direction from sending to receiving or from receiving to sending on a communications line.

Tutorial System Support
An education course, supplied with the operating system licensed program, that provides introductory education for a variety of computer users, including system operators and business and data processing professionals. Tutorial System Support is part of the total IBM curriculum for the AS/400 system, which consists of classroom training and other methods of self-study.

twinaxial cable
A cable made of two twisted wires inside a shield that is used on the 5250 family devices.

twinaxial data link control (TDLC)
A communications function that allows personal computers, which are attached to the work station controller by twinaxial cable, to use advanced program-to-program communications (APPC) or Advanced Peer-to-Peer Networking (APPN) support.

twisted-pair
Pertaining to a transmission medium that consists of two insulated conductors twisted together to reduce interference. For example, twisted-pair wiring can be used as an alternative to twinaxial cable.

two-phase commit
(1) The protocol that permits updates to protected resources to be committed or rolled back as a unit. During the first phase, agents are asked if they are ready to commit. If all agents respond positively, they are asked to commit their updates. Otherwise, the agents are asked to roll back their updates.
(2) A protocol that is used by the sync point manager to commit a transaction when resources that are managed independently are changed during the transaction. For example, two-phase commit would be used when databases on multiple systems are changed. If either the system or communications fail during a two-phase commit, the changes are guaranteed to be committed or rolled back according to the sync point manager's decision. See also one-phase commit.

two-port communications adapter cable
A cable that connects a 50-pin connector on a communications adapter card to two other communications cables that have 25-pin connectors (ports).

type
(1) In Java, a class or interface.
(2) In the Application Development Manager feature of the Application Development ToolSet licensed program, the third qualifier of a part name that uniquely identifies a part within a specific group by identifying the kind of information the part contains.
(3) In DCE X/Open Object Management (XOM), a category into which attribute values are placed on the basis of their purpose. See attribute type.

typed data
In OSI, a data transfer service provided by the session layer that enables an application entity to send data whether or not it has permission to send.

types
In OSI, a synonym for ASN.1 types.

type UUID
In DCE Remote Procedure Call (RPC), the Universal Unique Identifier (UUID) that identifies a particular type of object and an associated manager. See also manager and object.


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