Narrowband:-

In communications, a voice grade transmission channel of 2400 bits per second or less.

NDIR:-

A Novell NetWare workstation utility used to find and sort information about files and directories. It includes the following options.

• Format options allow users to view, create, update, archive, and copy information about files and directories.

• Sort options allow users to specify to display criteria, such as owner name, creation date, and file size.

• Attribute options allow users to sort file and directory information by attribute assignments.

• Restriction options allow users to restrict searches by owner, date, or size.

NetBIOS:-

Acronym for network basic input/output system, pronounced "net-bye-os." A session-layer network protocol, originally developed in 1984 by IBM and Sytek, to manage data exchange and network access.

NetBIOS provides an Application Program Interface- (API) with a consistent set of commands for requesting lower-level network services to transmit information from node to node, thus separating applications from the underlying network operating system. Many vendors provide either their own version of NetBIOS or an emulation of its communications service in their own products.

NetWare:-

A series of popular network operating, systems and related products from Novell, Inc. that run on Intel computers and supports DOS,  Microsoft, Windows, Macintosh, OS/2, and UNIX clients. Almost 80 percent of PC-based local-area networks (LANs) use Novell NetWare products; approximately 66 percent of LAN sales went to NetWare 3.x during 1994, approximately 10 percent went to NetWare 4.x, and 2 percent went to Personal NetWare. Systems range from the peer-to-peer Personal NetWare for a small number of users to the much larger NetWare 3.x, which can serve up to 250 users with 100,000 open files. Beginning in version 3.x, NetWare Loadable Modules (NLM's) allow network administrators to configure the network operating system running on the file server by adding individual modules as required for network security, workgroup productivity, or e-mail. The illustration on the following page shows the NetWare architecture. Several different NetWare operating systems are available, including the following:

• NetWare 2.x: A 16-bit operating system that is often run on 80286 servers and is most suitable for smaller, self-contained networks that do not connect to external computing resources. It can access 12 megabytes (MB) of memory and manage a maximum volume size of 255 MB, although volumes cannot span multiple hard disks. NetWare 2.x supports DOS, Macintosh, and OS/2 clients.

• NetWare 3.x: A 32-bit operating system that runs on 80386 (and later) processors and is suitable for larger, multi segment networks, with up to 250 nodes per server. NetWare 3.x can access up to 4 gigabytes (GB) of RAM (random-access memory) and up to 32 terabytes (TB) of storage. A maximum of 100.000 files can be open concurrently on the file server, and the maximum file size is 4 GB. Disk mirroring, disk duplexing, support for optical disks, and UPS-monitoring functions are all available.

• Net Ware 4.x: Adds support for optical disks, CD-ROMs, data compression, and improved login security mechanisms, as well as the Network Directory Services (NDS) which is based on the- CC1TT X.500 directory standard and replaces the bindery database of versions 2.x and 3.x. NetWare 4.1 is the first version of NetWare to integrate Message Handling Service with the directory, and it also adds System Fault Tolerance. NetWare 4.x is suitable for larger, multi segment inter-networks, supporting up to one thousand nodes per server. It includes a set of user and administrator utilities featuring a graphical user interface, and it is available in several languages.

Unlike with other software products, NetWare users do not always change to the next highest level of software release as a matter of course-from NetWare 3.x to NetWare 4.x, for example. Novell expends much time and effort in maintaining several parallel levels of network operating systems.

NetWare Management System:-

Abbreviated NMS. A system responsible for managing the network. NMS communicates using a network-management protocol and builds a map of network resources, which in turn can send messages to the server indicating unusual or error conditions on the network.

Network:-

 A group of computers and associated peripheral devices connected by a communications channel capable of sharing files and other resources between several users. A network can range from a peer-to-peer network connecting a small number of users in an office or department, to a local area network (LAN) connecting many users over permanently installed cables and dial-up lines, to a metropolitan-area network (MAN) or wide-area network (WAN) connecting users on several different networks spread over a wide geographic area.

Network Administrator:-

The person responsible for the day-to-day operation and management of a network; also known as a system administrator. Duties of the network administrator can include the following:

• Planning for future expansion.

• Installing new workstations and network peripheral devices.

• Adding and removing authorized users.

• Backing up the system and archiving important files.

• Assigning and changing passwords.

• Troubleshooting network problems.

• Monitoring system performance.

• Evaluating new products.

• Installing hardware and software updates.

• Training users.

Network Analyzer:-

Any device that decodes and analyzes data transmitted over the network. A network analyzer may be hardware, software, or a combination of the two. Some analyzers troubleshoot network problems by decoding packets; others create and transmit their own packets.

Network Architecture:-

The design of a network, including the hardware, software, access methods, and the protocols in use. Several well-accepted network architectures have been defined by standards committees and major vendors. For example, the International Standards

Organization (ISO) developed the seven-layer ISO/OSI model for computer-to-computer communications, and IBM designed SNA (Systems Network Architecture). Both of these architectures organize network functions into layers of hardware and software, with each layer building on the functions provided by the previous layer.

Network Control Program:-

Abbreviated NCP. In an SNA (Systems Network Architecture) environment, performs the routing, error control, testing, and addressing of SNA devices.

Network Device Driver:-

Software that controls the physical function of a network interface card. coordinating between the card and the other workstation hardware and software.

Network Directory:-

A directory located on a computer other than the one currently being used. Depending on access privileges, the rest of the disk may or may not be available to the user. On the Macintosh, a network directory is often referred to as a shared folder.

Network File System:-

Abbreviated NFS. A distributed file sharing system developed almost a decade ago by Sun Microsystems, Inc. NFS allows a computer on a network to use the files and peripheral devices of another networked computer as if they were local. NFS is platform-independent and runs on mainframes, minicomputers, RISC-based workstations, diskless workstations, and personal computers. NFS has been licensed and implemented by more than three hundred vendors.

Network Information Services:-

Abbreviated NIS. A recent name for the security and file-access databases on UNIX systems, previously known as the Yellow Pages. The NIS for most UNIX systems comprises the UNIX host files/etc/hosts/etc/passwd, and /etc/ group.

Network Layer:-

The third of seven layers of the ISO/OSI model for computer-to-computer communications. The network layer defines protocols for data routing to ensure that the information arrives at the correct destination node and manages communications errors.

Network Operating System:-

Abbreviated NOS. In typical client/server architecture local area networks (LANs), the NOS consist of two parts. The largest and most complex" part is the system software running on the file server. This system software coordinates many functions, including user accounts and network access information, security, resource sharing, administrative functions, UPS and power monitoring, data protection, and error detection and control. A much smaller component of the NOS runs on each of the networked PCs or workstations attached to the network. Examples of client/server NOSs include Novell NetWare, Banyan VINES, and Microsoft LAN Manager. In peer-to-peer networks, a part of the NOS is installed on each PC or workstation attached to the network and runs on top of the PC operating system. In some cases, the NOS may be installed on one PC designated as a file server, but this PC is not dedicated to the file server function; it is also available to run applications. Examples of peer-to-peer network operating systems include LANtastic, Personal NetWare, PowerLAN, and Windows for Workgroups.

Nil:-

Abbreviation for the National Information Infrastructure. A planned high-speed, public-access information service, designed to reach millions of schools, homes, and businesses throughout the United States.

NSFNET:-

Abbreviation for National Science Foundation Network. The NSFNET is not the Internet, but it is certainly a part of the Internet.

Null Modem:-

A short RS-232-C cable that connects two personal computers so that they can communicate without the use of modems. The cable connects the two computers' serial ports, and certain lines in the cable are crossed over so the wires used for sending by one computer are used for receiving data by the other computer.