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V.24: In data communications, a specification of the CCITT that defines the list of definitions for interchange circuits between data terminal equipment (DTE) and data circuit-terminating equipment (DCE).
V.25: In data communications, a specification of the CCITT that defines the automatic answering equipment or parallel automatic calling equipment or both on the General Switched Telephone Network, including procedures for disabling of echo controlled devices for both manually and automatically established calls.
V.25 bis: In data communications, an interim specification of the CCITT that defines the connection of data terminal equipment to a serial-dial interface of a public switched telephone network.
V.35: In data communications, a specification of the CCITT that defines the list of definitions for interchange circuits between data terminal equipment (DTE) and data circuit-terminating equipment (DCE) at data rates of 48 kilobits per second.
validation data: In Cryptographic Support, information about a customer used to create and verify the customer's personal identification number (PIN).
validity checking: (1) To verify the contents of a field.; (2) To verify that object names used in DB2® UDB for iSeries™ SQL statements exist on your system.
value: (1) In query management, a quantity assigned to a keyword or variable associated with a query command.; (2) Data (numbers or character strings) entered in any entry field, or supplied in parameters of commands.; (3) The smallest unit of data manipulated in SQL.
value type: In query management, one of the arguments passed to the extended interface. The value type specifies the data type of the value associated with the keyword.
variable: A name used to represent data that can be changed while the program or procedure is running. See also constant.
variable buffer: A storage area used to pass dialog variables between the application program and the user interface manager (UIM).
variable data: In AFP™ Utilities, an element in the record layout whose value is represented in the database file. See also fixed data.
variable length: The length of a record or field that can be changed. See also fixed length.
variable-length: Property of a record or field that can have a varying length. See also fixed-length.
variable-occurrence data item: In COBOL, a table element that is repeated a variable number of times. Such an item must contain an OCCURS DEPENDING ON clause in its data description entry, or be subordinate to such an item.
variable pattern: In REXX, a parsing pattern that uses variables to specify where a string of characters is parsed. The value of the variable can be set by the user and can change while running.
variable pool: In the user interface manager (UIM), the collection of dialog variables defined for an opened application program.
variable pool interface: In REXX, an application program interface that allows programs written in other languages to access variables being used by or contained in an active REXX program.
variable record: The named element of a panel group that identifies the content and layout for the storage area of the dialog variables.
variable symbol: In a REXX exec, a symbol that is assigned a value by the user or in some cases by the REXX/400 interpreter. The value of a variable symbol can be tested and changed using control statements.
varying-length string: In DB2 UDB for iSeries, a character string whose length is not fixed, but variable within limits. See also fixed-length string.
varied off: Pertaining to a device, controller, line, network interface, or independent disk pool unavailable for its normal, intended use.
vary off: To make a device, control unit, or line unavailable for its normal intended use.
varied on: See available.
vary on: To make an independent disk pool available for its normal, intended use. All of the primary and secondary disk pools in a disk pool group will vary on together.
VC: See virtual circuit.
vector: (1) In SNA, a data structure containing three fields: a length field that specifies the length of the vector in which it is contained, an identifier or type field, and a value field. The value field may contain subvectors.; (2) In the GDDM® function, a directed line segment, which is a straight line between two points.
vector symbol set (VSS): In the GDDM function, a set of characters each of which is treated as a small picture and is described by a sequence of lines and arcs. Characters in a vector symbol set can be drawn to scale, rotated, and positioned precisely. See also image symbol set.
Vendor Independent Messaging (VIM): An application program interface (API) defined by Apple Computer, Inc.; Borland International, Inc.; Lotus® Development Corporation; and Novell, Inc.
Venn diagram: A graphic image consisting of overlapping circles that represent the logical relationship of two sets of information.
verb: A reserved word that expresses an action to be taken by an application programming interface (API), a compiler, or an object program.
version: A separately licensed program that usually has significant new code or new function.
vertical format information: In TCP/IP, information, such as tab markers, that automatically positions lines of text with respect to other lines of text, according to defined rules. Vertical format information is usually associated with word processing.
Vertical Licensed Internal Code (VLIC): Programming that defines logical operations on data. The Vertical Licensed Internal Code translates the machine interface (MI) instructions.
vertically displayed records: Subfile records that are grouped so that each record is displayed on one or more lines. Each record begins a new line.
view: (1) The form in which an object is presented. A choice in the action bar that a user selects to look at an object from various perspectives is an example of a view.; (2) An alternative representation of data from one or more tables. A view can include all or some of the columns in the table or tables on which it is defined.
viewport: In the GDDM function, a rectangular area within the picture space that defines where the output of the current page appears on the work station.
VIM: See Vendor Independent Messaging.
virtual: Pertaining to not physically existing as such but made by software to appear to do so.
virtual address translation: The conversion of virtual storage addresses to real storage addresses.
virtual call: An X.25 user facility in which a call setup procedure and a call clearing procedure determine a period of communications between two DTEs in which the users' data will be transferred in the network in the packet mode of operation. All the users' data is delivered from the network in the same order in which it is received by the network. Synonym for switched virtual call.
virtual circuit (VC): In a packet-switching data network, a logical end-to-end transmission channel--as opposed to a physical connection--that connects X.25 users. Virtual circuits allow physical transmission facilities to be shared by many users simultaneously. A virtual circuit is a logical connection established between two DTEs. See also physical circuit.
virtual controller: (1) A controller description that is used by Advanced Peer-to-Peer Networking® (APPN) and high-performance routing (HPR) support to attach and manage APPN device descriptions. This type of controller does not represent a connection to a remote station.; (2) A controller description that emulates the function of a physical controller for communication with a remote device. As an example, when a PC is attached to a system, a virtual controller must be created to allow the PC to communicate with the system.
virtual device: A device description that does not have hardware associated with it. It is used to form a connection between a user and a physical work station attached to a remote system. A virtual device can be a virtual display station or a virtual printer.
virtual image: A CD or DVD image that is stored on system disks. Virtual images are stored in the integrated file system and can be in either Universal Disk Format (UDF) or ISO 9660 format.
virtual machine (VM): A functional simulation of a computer and its associated devices.
virtual node: The node associated with a connection network when a route is calculated that goes through that connection network.
virtual optical device: An optical device of type 632B that supports virtual optical images. This device can be created with the Create Device Description (Optical) (CRTDEVOPT) command by using a resource name (RSRCNAME) of *VRT.
virtual optical storage: Storage on system disks that appears to the user to be storage on an actual CD or DVD.
virtual party: In telephony, a party that does not actually take part in a telephone call. A virtual party is represented by a special directory number or numbers.
virtual printer: In iSeries Access, a printer attached to a host system that can receive output from a personal computer for printing. A virtual printer allows a user to use a printer attached to the host system as though the printer were directly attached to a personal computer.
virtual private network (VPN): An extension of a company's intranet over the existing framework of either a public or private network. A VPN ensures that the data that is sent between the two endpoints of its connection remains secure.
virtual processor: A setting that defines the assigned processing capacity represented to the operating system. Virtual processors represent a processing capacity less than that of a physical processor. A logical partition in the shared processor pool must have at least as many virtual processors as its assigned processing capacity.
virtual storage (VS): The storage space that can be regarded as addressable main storage by the user of a computer system in which virtual addresses are mapped into real addresses. The size of virtual storage is limited by the addressing scheme of the computer system and by the amount of auxiliary storage available, not by the actual number of main storage locations.
Virtual Storage Access Method (VSAM): An IBM® licensed program that controls communication and the flow of data in an SNA network. It provides single-domain, multiple-domain, and interconnected network capability. VSAM is emulated in CICS® to control access to files.
virtual terminal: A system object, created and controlled by an application program, that provides a functional representation or simulation of a physical display station.
virtual terminal manager (VTM): A Vertical Licensed Internal Code component that provides an interface to handle input/output to virtual devices on the system.
virtual terminal manager/function manager (VTM/FM): The function that provides an application program interface to terminal handling components residing below the machine interface on the system.
virtual workstation controller: A work station controller description that has the characteristics of a locally attached work station controller but does not exist as hardware.
virus: A program that can change other programs to include a copy of itself. The other programs are then said to be infected by the virus. Additionally, the virus can perform other operations that can take up system resources or destroy data.
Visual Explain: A tool that lets database administrators and application programmers use a graphical interface to display and analyze detailed information on the access plan of a given SQL statement. The tasks provided by this tool can be accessed from the Control Center.
vital product data (VPD): (1) In System Manager, self-defining information stored within the licensed programs, Licensed Internal Code groups, and hardware elements that comprise a system.; (2) A structured description of a device or program. For devices, it is recorded in the device at manufacture and includes at least the type, model, serial number, and installed features. It may include the manufacturer's ID and other fields. For programs, it is compiled as a data area accompanying the program and includes the name of the licensed program or Licensed Internal Code group, the release and modification, the program module names, the national language or languages selected, and possibly other fields. Vital product data is transferred from the device to the system and stored for display. Vital product data is also visible on the device name plate or a similar tag.
VLIC: See Vertical Licensed Internal Code.
VLIC log: A list of problem analysis information created by Vertical Licensed Internal Code.
VM: See virtual machine.
VM/MVS bridge: A function of the Communications Utilities for i5/OS™ licensed program that provides distribution services between an i5/OS SNADS network and both a VM Remote Spooling Communications Subsystem (RSCS) network and a Multiple Virtual Storage/Job Entry Subsystem (MVS/JES) network.
voice-grade telephone line: A telephone line that is normally used for voice communications. The line requires a modem for data communications.
voice response unit (VRU): Hardware and software used to answer incoming calls by playing one or more prerecorded messages.
volume: A storage medium that is put on or taken off the system as a unit, for example, magnetic tape or diskette.
volume label: An area on tape or disk that is used to identify the tape volume and its owner.
volume statistics: Statistical information about the activity on a tape, diskette, or cartridge volume including statistics about the session (such as the number of read, write, and retry operations), and lifetime (accumulated) statistics (such as the number of read and write errors and the number of bytes read and written).
volume table of contents (VTOC): (1) In the DYNIX/ptx® operating system, a partitioning driver. A VTOC file contains disk geometry information and defines the sizes and starting points of partitions on a disk.; (2) An area on a disk or diskette that describes the location, size, and other characteristics of each file, library, and folder on the disk or diskette.
vote: In the two-phase commit protocol, the response of an agent to the request of the initiator. The application transaction program uses the responses to determine if it should commit or roll back its protected resources.
voted read-only (VRO): The voted read-only logical unit of work (LUW) state indicates that the current LUW had no pending changes, was allowed to vote read-only, and did so.
vote read-only: The response, to a Prepare presentation services header with a Forget presentation services header, by the agent when no changes have been made to the resources, for the optimization of the two-phase commit flows.
VPD: See vital product data.
VPN: See virtual private network.
VRO: See voted read-only.
VRU: See voice response unit.
VS: See virtual storage.
VSAM: See Virtual Storage Access Method.
V-Series Recommendations: A document, CCITT Recommendation V-Series, that outlines standards for the interface between data terminal equipment (DTE) and a synchronous modem.
VSS: See vector symbol set.
VT100: A character-mode work station. Characters are sent immediately to the host system when a key is pressed.
VT100 workstation protocol: i5/OS support for the VT100 work station protocol that allows a user to access, using TELNET VT100 client support, VT100 application programs on other systems in a TCP/IP network. Users on other systems with a TELNET VT100 client emulation package are able to access i5/OS application programs through the i5/OS TELNET VT100 server.
VT220: A character-mode work station. Characters are sent immediately to the host system when a key is pressed.
VT220 workstation: An ASCII full-screen workstation manufactured by Digital Equipment Corporation (DEC).
VT220 workstation protocol: i5/OS support for the VT220 work station protocol that allows a user to access, using TELNET VT220 client support, VT220 application programs on other systems in a TCP/IP network. Users on other systems with a TELNET VT220 client emulation package are able to access i5/OS application programs through the i5/OS TELNET VT220 server.
VTM: See virtual terminal manager.
VTM/FM: See virtual terminal manager/function manager.
VTOC: See volume table of contents.