NAK

See Negative Acknowledgement.

Name Binding Protocol (NBP)

In AppleTalk, the transport-level protocol that interprets a socket client’s name, entered as a character string, into the corresponding DDP address. NBP gives AppleTalk protocols the capacity to discern user-defined zones and names of mechanisms by showing and keeping translation tables that map names to their corresponding socket addresses.

Named Pipes

An interprocess communication mechanism that is implemented as a file system service, allowing programs to be modified to run on it without using a proprietary application programming interface. Named pipes were developed to support more robust client/server communications than those allowed by the simpler NetBIOS. See also Operating System 2, File System and Interprocess Communications.

Name Renewal

Request sent by the client to notify the primary WINS server that it wants to continue using its registered name so that the server will reset the time-to-live (TTL).

Name Resolution

The DNS process of mapping a domain name to its IP address.

Name Resolution Component

The component that acts as a DNS server for other machines on the local network; this works as a “proxy” for DNS.

Name Server

A server that can give an authoritative answer to queries about its domain.

Name Service Provider Interface (NSPI)

Part of the DSProxy process that can accept Outlook client directory requests and pass them on to an address book provider. See also DSProxy.

Namespace

An environment in which every object has certain aspects in common with every other object. If, for instance, you were to create a domain named MyDomain.com, each object in the structure would have that (MyDomain.com) as a part of their name.

Naming Context

A self-contained section of a directory hierarchy that has its own properties, such as replication configuration and permissions structure. Active Directory includes the domain, configuration, and schema naming contexts. Exchange Server 5.5 also uses naming contexts; Organization, Address Book Views, Site, Configuration, and Schema.

Narrator

A Windows 2000 utility used to read aloud on-screen text, dialog boxes, menus, and buttons. This utility requires some type of sound output device.

Narrow-Band Radio

In narrow-band radio communications (also called single-frequency radio), transmissions occur at a single radio frequency.

NAT

See Network Address Translation.

NAT Editor

A component responsible for changing data in the protocols it supports.

NAT Interface

Network interface that supports Network Address Translation services for LAN clients.

National Model

A business model that covers an entire nation. Best identified by a complex infrastructure, multiple time zones, locations with different local laws and regulations, complex services, and large numbers of users.

Native API

The methods of data access that are specific to a certain database management system. Also called the proprietary interface. (API stands for application programming interface). These are generally implemented as a set of DLLs or COM-based objects.

Native Mode

In Microsoft Windows 2008 Server, a domain that contains only Windows 2008 domain controllers. See also Mixed Mode.

Native-Mode Active Directory

An Active Directory mode that allows the use of only Windows 2008 domain controllers and enhances group capabilities.

NBMA

See Non-Broadcast Multiple Access.

NBP

See Name Binding Protocol.

NDIS

See Network Driver Interface Specification.

NDS

See NetWare Directory Services.

Negative Acknowledgement (NAK)

A response sent from a receiver, telling the sender that the information was not received or contained errors. See also Acknowledgement.

Neighboring Routers

Two routers in OSPF that have interfaces to a common network. On networks with multiaccess, these neighboring routers are dynamically discovered using the Hello protocol of OSPF.

NetBEUI

See NetBIOS Extended User Interface.

NetBIOS

See Network Basic Input/Output System.

NetBIOS Extended User Interface (NetBEUI)

A simple Network layer transport developed to support NetBIOS installations. NetBEUI is not routable, and so it is not appropriate for larger networks. NetBEUI is the fastest transport protocol available for Windows NT.

NetBIOS Gateway

A service provided by RAS that allows NetBIOS requests to be forwarded independent of transport protocol. For example, NetBIOS requests from a remote computer connected via NetBEUI can be sent over the network via NWLink. See also Network Basic Input/Output System, NetWare Link, NetBIOS over TCP/IP, and NetBIOS Extended User Interface.

NetBIOS over TCP/IP (NetBT)

A network service that implements the NetBIOS IPC over the TCP/IP protocol stack. See NetBEUI, Transmission Control Protocol/Internet Protocol.

NetBSD

An implementation of Unix derived from the BSD series of releases; designed to run on Intel processors. The distribution is usually free, although there may be a small charge to cover the distribution media and packaging. NetBSD emphasizes multiple platform support and so has been ported to several non-Intel systems. See also FreeBSD and Linux.

NetBT

See NetBIOS over TCP/IP.

NetDDE

See Network Dynamic Data Exchange.

NetPC

An initiative from Compaq, Dell, Hewlett-Packard, Intel, and Microsoft describing a networked PC designed to give system administrators greater control and security than a traditional PC. NetPC is based on a minimum configuration of a 133MHz Pentium with at least 16MB of memory, running a Windows operating system, with a hard disk and the capability to run applications locally. The computer case is sealed and lockable, and floppy disks and CD-ROM drives are optional. All software distribution is centralized. See also Network Computer, Thin Client, Total Cost of Ownership, and Zero Administration for Windows.

NET USE

A command-line utility used to map network drives.

NetView

A mainframe network product from IBM, used for monitoring SNA (Systems Network Architecture) networks. It runs as a VTAM (Virtual Telecommunications Access Method) application.

NetWare

A popular network operating system developed by Novell in the early 1980s. NetWare is a cooperative, multitasking, highly optimized, dedicated-server network operating system that has client support for most major operating systems. Recent versions of NetWare include graphical client tools for management from client stations. At one time, NetWare accounted for more than 60 percent of the network operating system market. See also Windows NT, Client Services for NetWare, Gateway Services for
NetWare and NetWare Link.

NetWare Core Protocol (NCP)

The NetWare Core Protocol provides numerous function calls that support network services, such as file service, printing, name management, file locking, and synchronization. NetWare client software interfaces with NCP to access NetWare services.

NetWare Directory Services (NDS)

In NetWare, a distributed hierarchy of network services such as servers, shared volumes, and printers. NetWare implements NDS as a directory structure having elaborate security and administration mechanisms. The CSNW provided in Windows NT 4.0 supports the NDS tree. See also NetWare, Client Services for NetWare and Gateway Services for NetWare.

NetWare Link (NWLink)

A Windows NT transport protocol that implements Novell’s IPX. NWLink is useful as a general purpose transport for Windows NT and for connecting to NetWare file servers through CSNW. See also Internetwork Packet Exchange, Client Services for NetWare and Gateway Services for NetWare.

NetWare Link Services Protocol (NLSP)

A link state routing protocol used by routers (NetWare servers with two or more adapter cards can act as routers) to advertise networks when their address tables change.

NetWare NetBIOS Link (NWNBLink)

NetBIOS implemented over NWLink. See also Network Basic Input/Output System, NetWare Link, and NetBIOS over TCP/IP.

Network

A group of computers connected via some digital medium for the purpose of exchanging information. Networks can be based upon many types of media, such as twisted pair telephone-style cable, optical fiber, coaxial cable, radio, or infrared light. Certain computers are usually configured as service providers called servers. Computers that perform user tasks directly and that utilize the services of servers are called clients. See also Client/Server, Server, and Network Operating System.

Network Access Server (NAS)

The server on your network that accepts the Point-to-Point Protocol (PPP) connection from remote clients.

Network Adapter

The hardware used to connect computers (or other devices) to the network. Network adapters function at the Physical layer and the Data Link layer of the Open Session Interconnection (OSI) model. See also Physical Layer, Data Link Layer, and Open Session Interconnection Model.

Network Address

A unique address that identifies each node, or device, on the network. The network address is generally hard-coded into the network card on both the workstation and server. Some network cards allow you to change this address, but there is seldom a reason to do so.

Network Address Translation (NAT)

A service that allows multiple LAN clients to share a single public IP address and Internet connection by translating and modifying packets to reflect the correct addressing information.

Network Basic Input/Output System (NetBIOS)

A client/server interprocess communication service developed by IBM in the early 1980s. NetBIOS presents a relatively primitive mechanism for communication in client/server applications, but its widespread acceptance and availability across most operating systems makes it a logical choice for simple network applications. Many Windows NT network IPC mechanisms are implemented over NetBIOS. See also Interprocess Communications and Client/Server.

Network Basic Input/Output System (NetBIOS) Name

A computer identification method used prior to Windows 2000 for Windows clients to communicate with other computers on the network. WINS servers are used to resolve NetBIOS computer names to IP addresses. See also IP Address and WINS Server.

Network Binding

Links a protocol to an adapter so that the adapter can carry traffic using that protocol.

Network Client Administrator

A utility within the Administrative Tools group that can be used to make installation startup disks, make installation disk sets, copy client-based administration tools, and view remoteboot information.

Network Computer

An initiative from Apple, IBM, Netscape, Oracle, and Sun Microsystems describing a networked computer designed to give system administrators greater control and security than a traditional PC provides. The network computer is based on a minimum configuration of a 25MHz Intel i960 with at least 32MB of memory, running a Java Virtual Machine, and downloads applications from the server and runs them locally. Hard disk, floppy disk, and CD-ROM drives and expansion slots are not required. The initiative fizzled out, in part at least because conventional PCs can do the same job, but also due to Compaq (and other manufacturers) creating the sub-$1,000 PC. See also NetPC, Thin Client, Total Cost of Ownership, and Zero Administration for Windows.

Network Connectivity

Linking of segments of a single network.

Network Data Link Interface Standard (NDIS)

A Microsoft standard for network card drivers.

Network Directory

A directory used to organize and secure network resources.

Network Driver Interface Specification (NDIS)

A Microsoft specification to which network adapter drivers must conform in order to work with Microsoft network operating systems. NDIS provides a many-to-many binding between network adapter drivers and transport protocols. See also Transport Protocol.

Network Dynamic Data Exchange (NetDDE)

An interprocess communication mechanism developed by Microsoft to support the distribution of DDE applications over a network. See also Interprocess Communications and Dynamic Data Exchange.

Network File System (NFS)

Developed by Sun Microsystems, NFS is a family of file-access protocols that are a considerable advancement over FTP and Telnet. Since Sun made the NFS specifications available for public use, NFS has achieved a high level of popularity.

Network Group

A Windows special group that includes the users who access a computer’s resources over a network connection.

Network Information Center (NIC)

Originally there was only one, located at SRI International and tasked to server the ARPANET (and later DDN) community. Today, there are many NICs operated by local, regional, and national networks all over the world. Such centers provide user assistance, document service, training, and much more.

Network Interface Card (NIC)

Physical devices that connect computers and other network equipment to the transmission medium used. When installed in a computer’s expansion bus slot, a NIC allows the computer to become a workstation on the network. See also Ethernet, Token Ring, and Adapter.

Network Layer

The layer of the OSI model that creates a communication path between two computers via routed packets. Transport protocols implement both the Network layer and the Transport layer of the OSI stack. IP is a Network layer service. See also Internet Protocol, Transport Protocol, and Open Systems Interconnect Model.

Network Load Balancing (NLB)

A service in Windows that controls the distribution of traffic across multiple servers to provide better reliability and scalability for Internet server applications.

Network Management Processor (NMP)

A Catalyst 5000 switch processor module used to control and monitor the switch.

Network Monitor

A Microsoft program that analyzes frames coming and going, in real time, from the computer on which they run. Network Monitor records a number of statistics, including the percent of network utilization and the broadcasts per second. In addition, Network Monitor tabulates frame statistics (such as frames sent and received) for each network address.

Network Naming

Three services (DNS, DHCP, and WINS) that provide network name and address information to applications that request it.

Network News Transfer Protocol (NNTP)

An Internet protocol used to transfer newsgroup information between newsgroup servers and clients (newsreaders), and between newsgroup servers.

Network Operating System (NOS)

The software that runs on a file server and offers file, print, and other services to client workstations. Windows Server is a NOS. Other examples include NetWare, Banyan VINES, and IBM LAN Server. See also Windows NT, Server, and NetWare.

Network Printer

A network printer can use logical or physical ports. By defining a printer as a network printer, you make the printer available to local and network users. See also Printers, Print Device and Local Printer.

Network Security

Security that governs a network. See also Security, Network User and Local Security.

Network Server

Central computer which stores files for several linked computers.

Network Termination 1 (NT1)

Is an ISDN designation to devices that understand ISDN standards.

Network Termination 2 (NT2)

Is an ISDN designation to devices that do not understand ISDN standards. To use an NT2, you must use a terminal adapter (TA).

Network User

A user who logs on to the network using the SAM from a remote domain controller. See also Interactive User.

Newsfeed

The newsgroup data that is sent from one newsgroup server to other newsgroup servers.

Newsgroup

A Usenet e-mail discussion group devoted to a single topic. Subscribers to a newsgroup post articles that can be read by all the other subscribers. Newsgroup names fit into a formal structure in which each component of the name is separated from the next by a period. The leftmost portion of the name represents the category of the newsgroup, and the name gets more specific from left to right. Private newsgroups are often available on corporate intranets, where organization, structure, and subject matter are decided by the system administrator. See also Newsreader and Usenet.

Newsreader

An application used to read articles posted to Usenet newsgroups. Newsreaders are of two kinds: threaded newsreaders group the posts into threads of related articles, unthreaded newsreaders present articles in their original order of posting without regard for the subject. Of the two, threaded newsreaders are much easier to use. See also Newsgroup, Thread, and Usenet.

New Technology File System (NTFS)

A secure, transaction-oriented file system developed for Windows NT that incorporates the Windows NT security model for assigning permissions and shares. NTFS is optimized for hard drives larger than 500 MB and requires too much overhead to be used on hard disk drives smaller than 50 MB.

Next Hop Resolution Protocol (NHRP)

In a nonbroadcast multiaccess (NBMA) network, the protocol employed by routers in order to dynamically locate MAC addresses of various hosts and routers. In enables systems to communicate directly without requiring an intermediate hop, thus facilitating increased performance in ATM, Frame Relay, X.25, and SMDS systems.

Next Hop Server (NHS)

Defined by the NHRP protocol, this server maintains the next-hop resolution cache tables, listing IP-to-ATM address maps of related nodes and nodes that can be reached through routers served by the NHS.

NFS

See Network File System.

NHRP

See Next Hop Resolution Protocol.

NHS

See Next Hop Server.

NIC

See Network Interface Card.

NLSFUNC

Loads country-specific information.

NLSP

See NetWare Link Services Protocol.

NMP

See Network Management Processor.

NNTP

See Network News Transfer Protocol.

Node

In TCP/IP, an IP addressable computer system, such as workstations, servers, minicomputers, mainframes, and routers. In IPX networks, the term is usually applied to nonserver devices: workstations and printers.

Node Address

Used to identify a specific device in an internetwork. Can be a hardware address, which is burned into the network interface card or a logical network address, which an administrator or server assigns to the node.

Noise

A low-voltage, low-current, high-frequency signal that interferes with normal network transmissions, often corrupting data.

Non-Broadcast Multiple Access (NBMA)

A single router that can talk to multiple peers without using a broadcast.

Nonbrowser

A computer on a network that will not maintain a list of other computers and services on the network. See also Browser and Browsing.

Nondesignated Port

The Spanning-Tree Protocol tells a port on a layer-2 switch to stop transmitting and creating a network loop. Only designated ports can send frames.

Nonreturn to Zero (NRZ)

One of several encoding schemes for transmitting digital data. NRZ signals sustain constant levels of voltage with no signal shifting (no return to zero-voltage level) during a bit interval. If there is a series of bits with the same value (1 or 0), there will be no state change. The signal is not self-clocking. See also Nonreturn to Zero Inverted.

Nonreturn to Zero Inverted (NRZI)

One of several encoding schemes for transmitting digital data. A transition in voltage level (either from high to low or vice-versa) at the beginning of a bit interval is interpreted as a value of 1; the absence of a transition is interpreted as a 0. Thus, the voltage assigned to each value is continually inverted. NRZI signals are not self-clocking. See also Nonreturn to Zero.

Non-Stub Area

In OSPF, a resource-consuming area carrying a default route, intra-area routes, interarea routes, static routes, and external routes. Non-stub areas are the only areas that can have virtual links configured across them and exclusively contain an autonomous system boundary router (ASBR). See also Autonomous System Boundary Router and OSPF.

Non-Volatile Random Access Memory (NVRAM)

Random-access memory that keeps its contents intact while power is turned off.

Normal Backup

A backup type that backs up all selected folders and files and then marks each file that has been backed up as archived.

Normalization of Data

The process of organizing data into tables, in a consistent and complete format, in order to create a relational database.

Notebook Computer

A small, portable computer, about the size of a computer book, with a flat screen and a keyboard that fold together. A notebook computer is lighter and smaller than a laptop computer. Recent advances in battery technology allow them to run for many hours between charges. Some models use flash memory rather than conventional hard disks for program and data storage; other models offer a range of business applications in ROM. Many offer PCMCIA expansion connections for additional peripheral devices, such as modems, fax modems, and network connections. See also Laptop Computer and PC Memory Card International Association.

Not In The Wild

Viruses “not in the wild” are in the real world but fail to spread successfully. See also In The Wild and Zoo Virus.

Novell Directory Services (NDS)

The brand name for Novell’s network directory.

Novell ManageWise

A software package from Novell for managing NetWare and Microsoft Windows NT servers. ManageWise includes server and desktop management, network analysis, software management, virus protection, and automatic network inventory. ManageWise replaces NetWare Management System on Novell servers. See also Novell Z.E.N.works.

Novell Z.E.N.works

A software management package from Novell that provides desktop management, including hardware inventory, and adds flexibility to the desktop policy capabilities built into Microsoft Windows. Z.E.Nworks can also control the applications a client can run and can operate the client remotely. See also Novell ManageWise.

NRZ

See Nonreturn to Zero.

NRZI

See Nonreturn to Zero Inverted.

NSLOOKUP

A tool that allows one to query a DNS server to see what information it holds for a host record.

NT1

See Network Termination 1.

NT2

See Network Termination 2.

NTBOOTDD.SYS

A file accessed in the Windows boot sequence. NTBOOTDD.SYS is an optional file (the SCSI driver) that is used when the computer has a SCSI adapter with the on-board BIOS disabled. See also Basic Input/Output System.

NTDETECT.COM

A file accessed in the Windows boot sequence. NTDETECT.COM is used to detect any hardware that is installed and add information about the hardware to the Registry. See also Registry.

NT Directory Services

The synchronized SAM database that exists between the PDC and the BDCs within a domain. Directory Services also controls the trust relationships that exist between domains. See also Security Accounts Manager, Primary Domain Controller, Backup Domain Controller and Trust Relationship.

NT Event Viewer

A Windows utility ised to view Windows events and errors. The Application log records SQL Server events and errors as well as events from other applications running under Windows.

NTFS

See New Technology File System.

NTFS Permissions

Permissions used to control access to NTFS folders and files. Access is configured by allowing or denying NTFS permissions to users and groups. See also New Technology File System.

NTLDR

A file used to control the Windows boot process until control is passed to the NTOSKRNL.EXE file. See also Boot and NTOSKRNL.EXE.

NTOSKRNL.EXE

A file accessed in the Windows boot sequence. NTOSKRNL.EXE is used to load the kernel. See also Boot and Kernel.

NTUSER.DAT

The file that is created for a user profile.

NTUSER.MAN

The file that is created for a mandatory profile.

NVRAM

See Non-Volatile Random Access Memory.

NWLink

See NetWare Link and Internetwork Packet Exchange.

NWNBLink

See NetWare NetBIOS Link.