N n See nano. nailed-up connection Connection established on a semi-permanent basis through a switching center. NAK See negative acknowledgment. NAM Network Access Machine. nano (n) A prefix for one billionth of a specific unit. nanosecond (nsec) One billionth of a second; a millimicrosecond. NANP North American Numbering Plan. NAP Network Access Pricing. NAPTP See North American Precise Tone Plan. narrowband channel Sub-voicegrade channel with a speed range of 100 to 200 bps. narrowband PCs A connection-oriented and connectionless digital wireless communications services that utilizes channels in the 800 to 900 MHz SMR band already auctioned by the FCC. NARUC National Association of Regulatory Utility Commissioners. NAS Network Application Support; Digital Equipment's proprietary computing environment that supports multivendor interoperability and development. NATA North American Telecommunications Association. National Bureau of Standards (NBS) See National Institute for Standards and Technology. National Institute for Standards and Technology Formerly known as the National Bureau of Standards, this division of the U.S. Department of Commerce insures standardization in non-defense government agencies. NAU Network addressable units. NCGA National Computer Graphics Association. NCP See Network Control Program. NCP/VS Network Control Program/Virtual Storage (IBM). NCS 1. NCR Century Software. 2. Network Computing System (HP/Apollo). NCSC National Computer Security Center. NCSL National Computer Systems Laboratory; a research componentof NIST. NDIS See network driver interface specification. NDL Network Definition Language (Unisys). near-line storage Optical disk storage products that are removable, durable, and have randomly accessible media and slower access times than on-line storage. Usually refers to jukeboxes, but includes multi-function, CD-ROM, and rewritable magneto-optical drives. near-typeset Page printers that have 300 dpi or higher resolution. Real typesetters have 1,200 dpi and above resolutions. negative Photographic print in which tone values are reversed - white for black, lights for darks, darks for lights, and black for white. Generally produced on film, for the purpose of print or platemaking. negative acknowledge character Control character sent to a transmitting station to indicate receipt of communications with one or more errors. negative acknowledgment (NAK) A response sent by the receiver to indicate that the previous block was unacceptable and that the receiver is ready to accept a retransmission. NetBEUI See NetBIOS extended user interface. NETBIOS See network basic input/output system. NetBIOS extended user interface (NetBEUI) A protocol that conforms to the NetBIOS application programming interface; commonly used in PC-based LAN operating systems such as LAN Manager and LAN Server; originally developed for use with token-ring adapters. NetIPC Network interprocess communications. NetNews An Internet network that lets users share information and opinions. NETS Normes Europeans de Telecommunications. NetView IBM SNA network management software designed to manage a communications network from a central computer. NetWare Novell's popular LAN operating system. NetWare runs on most popular LAN adapters. netware loadable module (NLM) An application residing on a NetWare server that coexists with the core NetWare operating system files and provides improved performance and tighter integration than applications not running at NLMs. network A system of terminals interconnected by communications channels that can be reserved for the exclusive use of one customer (private network) or for the use of many customers (shared network). network administrator Individual responsible for issuing passwords, assigning shared resources, managing and maintaining optimum network traffic conditions, and performing other LAN-user functions. network architecture Refers to the structure and protocols employed in a computer network. network basic input/output system (NETBIOS) A set of functions that permits communication across IBM LANs. NETBIOS is also used by LAN programs and other product to communicate with other systems. NETBIOS-compatible products provide the same features in the same way, enabling users with NETBIOS-compatible products to run programs designated for the IBM environment. network control program (NCP) Software that runs on IBM communications controllers, such as the 3725, to manage the network and support the host interface to the network. network data base A central repository for network device, application, and user specifications. network driver interface specification (NDIS) A standard established by Microsoft for writing hardware-independent drivers. network file system (NFS) An extension of TCP/IP that permits files on remote nodes of a network to appear locally linked. network gateway Equipment used to connect different network architectures using different protocols by providing protocol translation. network inward/outward dialing (NIOD) Capacity to dial into or from the public telephone network directly from a PBX. network layer In the OSI model, the layer that provides the functions and procedures used to transfer data from the transport layer to and through the network. network management The management of a switched network to provide the greatest possible efficiency with economy; avoiding congestion on public networks by switching to alternate routes on long distance calls. network numbering exchange (NXX) The three-digit location code representing the central office. "N" may be any number between 2 and 9 and "X" may be any number." network operating system A control program that resides in a file server within a local area network. network printer A printer shared by multiple computers over a network. See local printer. network redundancy Duplicated network equipment and/or data which can provide a backup in case of network failures. network security Defensive measures (hardware or software) used to impose user-access restrictions on a network. network terminating unit (NTU) Component of the network that links directly to the data terminating equipment. network topology The physical arrangement between nodes of a network. Network are usually considered star, ring, tree, or bus, or a combination of the various types. network trunks Circuits connecting switching centers. networking The linking of separated computers using transmission media. networkMCI NetworkMCI outlines MCI's strategy for the future, as telephony, computers and television converge into interactive multimedia and wireless communications. neural network OCRs OCR software which compares characters to a large number of prerecorded samples. As new variations on a character are introduced, the neural network accepts them and therefore "learns" in a way analogous to human (neural) learning. neutral transmission Method of transmitting teletypewriter signals. A mark (or signal) is represented by current on the line and a space by the absence of current. newbie A new Internet user. newsgroups Similar to a bulletin board, to which users can post articles related to a particular topic. NFS Sun Microsystem's Network File System protocol. NFS permits IP machines to mount and use the file systems of other IP machines. nibble A four-bit word. night answer A PBX feature that allows all incoming calls to be automatically redirected to a preselected station or answered at any station using a 1- or 2-digit call pickup code. night service Calls usually directed to the attendant are routed to preselected station lines within a PBX system. Routes can be assigned on a flexible basis by the attendant and remain in effect until changed. Also called fixed night service. NII National Information Infrastructure, a Clinton administration proposal for federal control of the internet. NIOD See network inward/outward dialing. NIS Network Imaging Server. NISO National Information Standards Organization. NIST See National Institute for Standards and Technology. NIU Network Interface Unit; translates data from the workstation's software and processor into a format that can be transmitted through the network. NLM See netware loadable module. NLQ Near Letter Quality. A printer whose output is almost as good as a typewriter. NLS X/Open's Native Language System; a set of interfaces designed to facilitate the development of applications that can operate in many different language and cultural environments. NMOS N-channel metal oxide semiconductor. NMS Network Management Station. NND National number dialing. See also national number. NNI Network-Network Interface, an ATM standard. NNX code Older version of network numbering exchange. See network numbering exchange (NXX). No read A bar code term. When a pass over a bar failed to register. node In a topological description of a network, a node is a junction of the links. NOI Node Operator Interface. noise 1. Interference in an audio or video signal. Random electrical signals, introduced by circuit components or natural disturbances that tend to degrade the performance of a communications channel. 2. Irrelevant specks or marks on paper documents that degrades OCR performance. noise word Irrelevant or inconsequential words that are ignored by a test-retrieval index. "The," "a," "so" are almost always considered noise words. NOMAD Algebraic language compiler adapted from the Michigan Algorithmic Decoder (MAD). non-impact printer A printer that uses any technique - ink-jet, thermal laser - besides having keys that strike the paper. non-interlaced Illuminating a CRT by displaying lines sequentially from top to bottom. Non-interlaced monitors eliminate flicker found in interlaced monitors which illuminate half the lines in the screen in the first cycle and the remaining half in the second cycle. non-printing character A character in a transmission code which performs a control function but is not reproduced when the transmission is printed. non-process runout To send paper through the printer at the end of a job without printing anything on it. non-volatile The ability to retain information without external power applied. Hard drives, floppy diskettes and ROMs are non-volatile - their contents are preserved when the computer is off. non-wireline The cellular service provider that is not the local telephone company. nonblocking A PBX function that allows any PBX port to access any other system port to ensure connection with outside lines and/or trunks, even during periods of heavy traffic volume. nondeterministic network A network in which the access delay cannot be predicted with certainty, because it is based on a probability function. Also called stochastic network. nonlinear Storage in random access, versus the contiguous linear method of tape. Access time to data stored on nonlinear devices (CD-ROMs, optical discs, hard disks) is faster than linear devices (tape). nontransparent mode The transmission of characters in a defined code set in which all characters are interpreted or transformed. Compare with transparent mode. nonvolatile storage Memory storage that does not lose its contents when power is removed. North American Precise Tone Plan (NAPTP) The standard method of registering call progress tones. North American Television Systems Committee (NTSC) Committee that standardizes transmission of television signals in the U.S. and Canada. NOS Network Operating System (Control Data). NOVA Computer series (Data General). NPA See area, numbering plan; numbering plan area. NPS Network Processing Supervisor (Bull HN). ns or nsec See nanosecond. NSAP addresses Network Service Access Point; addresses that identify a network layer entity on an OSI network. NSFNET The National Science Foundation Network, links government agencies, supercomputer centers, universities and industry research organizations across the world. NSFNET is faster and more powerful than Internet. NSP 1. Network Services Protocol (Digital Equipment). 2. Network Support Processor. NTCA National Telephone Cooperative Association. NTIA National Telecommunications and Information Administration. NTU See network terminating unit. NuBus A 32-bit bus architecture that was developed at MIT and originally used in Apple's Macintosh II Series. Current Macs have one or more NuBus slots for peripheral expansion. NUL Null character. null modem A dummy device used to interface a peripheral and computer that anticipates using a modem when none is required. numbering plan area (NPA) A geographical division (expressed as three numbers) within which no two telephones are assigned the same 7 digit number. The first number is any number between 2 and 9; the second is always 1 or 0; and the third is any number excluding 0. Also called area codes. numbering plan area (NPA) A geographical division (expressed as three numbers) within which no two telephones are assigned the same seven-digit number. numeric Text or data made up of the digits 0-9 only. numeric machine print recognition OCR that has been restricted to recognizing only numeric characters, greatly improving its accuracy on numbers-only text. NVLAP NIST's National Voluntary Laboratory Accreditation Program; accredits outside GOSIP certification laboratories. NVOD Near-video-on-demand. NXX See network numbering exchange. Nyquist's Criterion A rule of thumb for determining the amount of digital sampling necessary to reproduce an analog wave.