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Glossary


N

n. See en.

NA. Not applicable.

name. (1.) A sequence of 1 to 250 alphanumeric characters, the first of which must be alphabetic, that identifies a data object. (2.) In Ada language, a name is a construct that stands for an entity: it is said that the name denotes the entity, and that the entity is the meaning of the name. See also declaration and prefix. (3.) In C++, a name is commonly referred to as an identifier. However, syntactically, a name can be an identifier, operator function name, conversion function name, destructor name, or qualified name. See also symbolic name.

name-lookup method resolution. Similar to the method resolution techniques employed by Objective-C and Smalltalk. In SOM, it is significantly slower than offset resolution. Name-lookup resolution, unlike offset resolution, can be used when the name of the method to be invoked is not known until run time, or the method is added to the class interface at run time, or the name of the class introducing the method is not known until run time.

name resolution. The process of translating (resolving) a symbolic name into its more efficient Internet address.

name server. A host that provides name resolution for a network. Name servers translate symbolic names assigned to networks and hosts into the efficient Internet addresses used by machines.

name string. A character string that identifies one of a variety of objects such as an icon, a resource, or a font.

named common. In FORTRAN, a separate common block consisting of variables and arrays and given a name.

named pipe. A pipe that an application opens by name in order to write data into or read data from the pipe. By convention, named pipes are placed in the /dev directory and are treated as special files. Using a named pipe facilitates communication between a sending process and a receiving process.

naming scope. See scope.

NaN. See not-a-number.

national language support. Conversion subroutines for languages other than American English that translate between various character sets and date and time string formats. Synonymous with international character support.

national terminal number (NTN). In X.25 communications, the 1- to 12-digit number that follows the country code in the network user address.

natural or social science format. The style of bibliography entry favored by writers in the natural and social sciences.

navigation keys. In CDE, the keyboard keys used to move the current location of the cursor. These include the arrow keys (with or without the Control key); the Tab key (with or without the Control or Shift keys); the Begin and End keys (with or without the Control key); and the Page Up and Page Down keys.

NCA. See Network Computing Architecture.

NCCF. See Network Communications Control Facility.

NCK. See Network Computing Kernel.

NCS. See Network Computing System.

NCS cell. A logical concept of grouping together one or more machines in an NCS network. Any node belonging to an alternate cell may only have their license requests satisfied by License Use Management servers in that cell. Nodes outside the cell may not make license requests to servers in another cell. Two types of cells, default and alternate, are used to provide two ways of accessing License Use Management servers.

NDC. See normalized device coordinates.

negative response. In data communications, a reply indicating that data was not received correctly or that a command was incorrect or unacceptable.

negotiation. In X.25 communications, the process by which two DTEs establish the packet size, packet window size, and throughput class to be used during a call procedure. Contrast with validation.

neighbor gateway. One of the peers acquired by an exterior gateway. All exterior gateways do not communicate with all other exterior gateways. Instead, they acquire neighbors through which they communicate.

nest. (4.) To incorporate a structure or structures into a structure of the same kind. (5.) To place subroutines or data in other subroutines or data at a different hierarchical level. Therefore, the subroutines can be run as recursive subroutines or so that the data can be accessed recursively. (6.) A self-contained software element that completely encompasses a similar software element is said to have that similar element "nested" within it. Examples include software loops (the nested loop) nested within larger loops (the nesting loop) and submenus nested within menus.

nested class. A C++ class defined within the scope of another class.

nested DO. In FORTRAN, a DO loop or DO statement in which the range is entirely contained within the range of another DO loop.

nested transaction. A transaction begun within the scope of another transaction. These are also referred to as subtransactions.

NETASCII. Eight-bit ASCII with the first bit always set high, for error checking.

NetBios. Network Version of Basic Input/Output System.

NetLS. See License Use Management.

netlsd. The command used to invoke the network license server daemon.

network. A collection of data processing products that are connected by communication lines for information exchange between locations.

network adapter. Circuitry that allows devices to communicate with other devices on the network.

network address. (1.) The part of an address indicating a specific network. A complete address for a machine on a network consists of the network address and the host address. (2.) In NCS, a unique identifier (within an address family) for a specific host on a network or an internet. The network address is sufficient to identify a host, but does not identify a communication end point within the host.

network boot image. A boot image that supports standalone, diskless, and dataless machines.

Network Communications Control Facility (NCCF). A licensed program that serves as a base for command processors that can monitor, control, and improve the operation of a network.

Network Computing Architecture (NCA). A set of protocols and architectures that support distributed computing.

Network Computing Kernel (NCK). The combination of the RPC runtime library and the Location Broker, which contain the necessary pieces required to run distributed applications.

Network Computing System (NCS). A set of software tools developed by Apollo Computer Inc. that conform to the Network Computing Architecture. These tools include the Remote Procedure Call runtime library and the Location Broker. NCS is the underlying communications protocol used by License Use Management to transmit licensing transactions between clients and servers. Messages are broadcast from clients to the NCS-managed network.

Network File System (NFS). A distributed file system that enables users to access files and directories located on remote computers and treat those files and directories as if they were local. NFS is independent of machine types, operating systems, and network architectures through the use of remote procedure calls (RPC).

Network Information Center (NIC). The publication distribution center for DARPA TCP/IP information.

Network Installation Management (NIM). An environment that provides installation and configuration of software within a network interface.

network interface. The software that formats packets at the network layer into packets that specific network adapters can understand and transmit.

Network License System. See License Use Management.

network management. The conceptual control element of a data station that interfaces with all of the layers of that data station and is responsible for the setting and resetting control parameters, obtaining reports of error conditions, and determining if the station should be connected to or disconnected from the medium.

network mask (netmask). A 32-bit mask used to identify the most local portion of a local area network (LAN).

network object. An entry in the Network Installation Management (NIM) database that represents a local area network.

network protocol. A communications protocol from the Network Layer of the OSI network architecture, such as the Internet Protocol (IP).

network provider. In X.25 communications, the organization, often a PTT, that provides a public network.

network state. A state that indicates either that the network object can participate in NIM operations or an error in the definition of the network object.

network terminating unit (NTU). In X.25 communications, the point of access to the network.

Network Time Protocol (NTP). Internet-recommended time standard.

network user . A kernel-level protocol or user-level application that accesses the services of the network layer.

network user address (NUA). In X.25 communications, the X.121 address containing up to 15 binary code digits.

network user identification (NUI). (1.) The facility that enables the transmitting DTE to provide billing, security, or management information on a per-call basis to the DCE. (2.) The NUI can identify a network user independent of the port being used. See also address.

new. In C++, a keyword identifying a free store allocation operator. The new operator may be used to create class objects.

new installation. An installation method used when the fixed disk or disks you are installing BOS onto are empty. A hard disk is considered empty if it does not contain any data or if it contains data not in a volume group.

new-line character (NL). A control character that causes the print or display position to move down one line. This character is represented by '\n' in the C language. Usually a carriage return is implicitly associated with an NL.

new-process image. A new program laid over the current program by the exec subroutine.

next. The dialog management action for dependent workstations that causes the next portion of a data object to be presented.

NFS. See Network File System.

NIC. See Network Information Center.

nice value. A number that is used to bias the priority of a process. A higher number results in a lower priority.

nickname. Synonym for alias.

NIM. See Network Installation Management.

NIM routing. The information that defines which networks in the NIM environment can communicate with each other and which gateways they use to facilitate that communication. NIM routing is used to represent the TCP/IP routine that exists for the LANs in the overall network environment.

NIS. Network Information Service. A distributed database that allows you to maintain consistent configuration files throughout your network.

NL. See new-line character.

node. (1.) A computer connected to a network. (2.) An end point of a link, or a junction common to two or more links in a network. Nodes can be processors, controllers, or workstations, and they can vary in routing and other functional capabilities. (3.) In Systems Network Architecture the portion of a hardware component, along with its associated software components, that implements the functions of the seven architectural layers (SNA). (4.) In a tree structure, a point at which subordinate items of data originate.

node ID. A unique string of characters that identifies the node on a network.

node verification. An additional level of security beyond that provided by the network addressing scheme. Node verification helps to ensure that a connection reaches the correct remote station. It is available on LU6.2 connections only. See also BIND password.

nodelock file. The text file at a user node (rather than at a license server node) where nodelocked licenses are added. The nodelock file is located in the /usr/lib/netls/conf directory.

nodelocked license. A type of license locked to a specific node so that the product may only be used at that node. The license server does not administer nodelocked licenses.

nodes. Systems connected in a network to form a monitor cell.

no-input zone. Synonym for dead zone.

noise. (1.) A disturbance that affects a signal and potentially distorts the information carried by that signal. (2.) Random variations of the characteristics of any entity, such as voltage, current, or data. (3.)A random signal of known statistical properties of amplitude, distribution, and spectral density.

nolock lock. A dummy lock mode that is used when a lock mode must be supplied, but when actually locking the data is not required. Functions specifying this lock mode can read data even when it is currently locked by other operations or transactions, enabling dirty reads to be performed. This type of lock is operationally consistent, which means that using it to lock and read a value will return an actual value that was correct at some moment in time, but is not transactionally consistent.

nondeterministic program. A program whose results cannot be determined by analyzing the source code. A program that does not initialize variables before their first use is nondeterministic, because the value of an uninitialized variable can change between runs of the program.

nonexecutable program unit. In FORTRAN, a block data subprogram.

nonexecutable statement. A statement that describes the characteristics of a program unit, data, editing information, or statement functions, but does not cause any action to be taken.

non-extended result. An exception notification that does not have any data defined in the result_ext file of the dlc_getx_arg structure.

non-printing character. Synonym for control character.

non-productive. Data traffic on the media that is only made up of repetitive control information and does not contain end user data.

non-return-to-zero (NRZ). A binary code system in which a signal condition must be sustained for the full time interval and does not revert to a standby or quiescent state between signal elements. Using NRZ permits the maximum data signaling rate on the channel, which should be twice the band width, according to Nyquist's theorem.

nonspacing character. See diacritic.

nonspacing character sequence. For accented characters, a two-part sequence consisting of a valid diacritic followed by an alphabetic character or a space. The system converts the sequence into a single code point that results in the alphabetic character with the specified diacritic mark.

nonswitched line. (1.) A connection between computers or devices that does not have to be established by dialing. (2.) A dedicated line. Synonym for leased facility. Contrast with switched line.

nonswitched network. On a network, a connection between computers or devices that does not have to be established by dialing.

nonterminal symbol. The structure that the parser recognizes.

nonvolatile random access memory (NVRAM). Random access memory (storage) that retains its contents after the electrical power to the machine is shut off. A specific part of NVRAM is set aside for use by the system ROS for the boot device list.

nonzero. A value that is not equal to zero.

normal attachment stop. See normal stop.

normal mode. See multiuser mode.

normal port. A port that is asynchronous and allows users to log in. No outgoing use of the port is allowed while it is enabled.

normal stop. One of two ways to stop an attachment. (The other way is a forced stop.) If the attachments or any of their connections are in a pending state, SNA Server rejects the normal stop attachment action.

normalized device coordinates (NDC). In GL, coordinates in the range from -1 to 1. All primitives that draw within the unit cube are visible on the screen (unless masked by the screen mask). See also transformation and unit cube.

not-a-number (NaN). In binary floating-point computations, a value, not interpreted as a mathematical value, that contains a mask state and a sequence of binary digits.

notify flag. A parameter that indicates whether a reply is required at that point in an event loop.

nroff. A typesetting utility originally designed to drive Teletype model 37 printing workstations. It now drives a wide variety of backspacing and non-backspacing tty-type line printers and tty-emulating printers.

NRZ. See non-return-to-zero.

NS. Network Systems. Also, Network Services.

NSA. Next station addressing.

NSI. Name Service Interface.

NTN. See national terminal number.

NTP. See Network Time Protocol.

NTSC. A national television industry broadcasting standard as defined by the National Television Standard Committee used in the USA, Canada, Japan, and other countries. A video display and timing format that is the American broadcast standard. Most video tape recorders record and play back NTSC signals. Specialized hardware is required to convert from RGB monitor outputs to an NTSC signal. See also PAL and SECAM.

NTSC signal. A signal as defined by the National Television Standard Committee. Also called composite video.

NTU. See network terminating unit.

NUA. See network user address.

NUI. See network user identification.

NUL. See null character.

NUL character. In XPG4 system interface, a character with all bits set to zero.

null. Empty, having no value, containing nothing.

NULL. In the C language, a pointer guaranteed not to point to a data object.

null character (NUL). (1.) The hex 00 character used to represent the absence of a printed or displayed character. (2.) A control character used to accomplish media-fill or time-fill that can be inserted into or removed from a sequence of characters without affecting the meaning of the sequence. (3.)A control character used to delimit a string of characters.

null character string. Two consecutive single quotation marks that specify a character string consisting of characters.

null modem. See modem eliminator.

null signal. A signal parameter of 0 (zero).

null statement. A statement that consists of a semicolon.

null-terminated. Having a zero byte at the end. In the C language, character strings are stored this way internally.

numeric. Pertaining to any of the digits 0 through 9.

numeric character. See digit.

numeric constant. A constant that expresses an integer, real, or complex number.

numeric error. A situation where the result of a real or integer expression exceeds a compiler's limits (or limits imposed by the programming language) for such expressions.

numeric literal. A numeric character or string of characters whose value is implicit in the characters themselves. For example, 777 is literal as well as the value of the of the number 777. A numeric literal can contain any of the numeric digits 0 through 9, a plus or minus sign, and a decimal point. Contrast with character literal.

NURBS. (Non-Uniform Rational B-spline). A parametric surface that can be trimmed with nonuniform rational B-spline curves and piecewise linear curves. See also trimming loops.

NVRAM. See nonvolatile random access memory.


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