Abend — When the operating system finds a serious problem, such as a hardware failure, it performs the abend procedure to stop the NetWare server and produces a message.

Accelerated Graphics Port (AGP) — A high-performance, component-level interconnect for 3D-graphics applications.

Access Control List (ACL) — (1) Property of a particular object that contains information about who can have access to that object. (2) A list of security identifiers contained by an object. Only the processes identified on the ACL with appropriate permissions can activate the services of that object.  Each ACL is made up of access control entries (ACEs), which specify access or auditing permissions to that object for one user or group. There are three ACE types—two for discretionary access control and one for system security.  The discretionary ACEs are AccessAllowed and AccessDenied. Respectively, these explicitly grant and deny access to a user or group of users. The first AccessDenied ACE denies the user access to the resource, and no further processing of ACEs occurs.   Each ACE includes an access mask, which defines all possible actions for a particular object type. Permissions are granted or denied based on this access mask.   One way to think of an access mask is as a sort of menu from which granted and denied permissions are selected.

Access method — the way in which a node is permitted to send data over the media. With Ethernet, the node listens to the line to determine if it is available before transmitting.

Access permission — A rule associated with an object (usually a directory, file, or printer) to regulate which users can have access to the object and in what manner. See also user right.

Access privileges — Permissions set by Macintosh users that allow them to view and make changes to folders on a server. By setting access privileges (called permissions when set on the computer running Windows NT Server) you control which Macintoshes can use folders in a volume. Services for Macintosh translates access privileges set by Macintosh users to the equivalent Windows NT permissions.

Access Tokens — Objects containing the security identifier of a running process. A process started by another process inherits the starting process’s access token. The access token is checked against each object’s ACL to determine whether appropriate permissions are granted to perform any requested service.

Accessibility — The extent to which computers are easy to use and available to a wide range of users, including people with one or more physical disabilities.

Account — See user account; group account.

Account lockout — A Windows NT Server security feature that locks a user account if a number of failed logon attempts occur within a specified amount of time, based on account policy lockout settings. (Locked accounts cannot log on.) See also password parameters.

Account policy — Controls the way passwords must be used by all user accounts of a domain, or of an individual computer. Specifics include minimum password length, how often a user must change his or her password, and how often users can reuse old passwords. Account policy can be set for all user accounts in a domain when administering a domain, and for all user accounts of a single workstation or member server when administering a computer.

Accounting — A means of keeping track on the resources used on the network

Accounts — Containers for security identifiers, passwords, permissions, group associations, and preferences for each user of a system. In Windows NT, the User Manager administration tool is used to create and manage accounts.

Achitecture — The logical design and construction of parts of a computer or communication networks.

ACK — Short for acknowledgment. The transmission control protocol (TCP) requires that the recipient of data packets acknowledge successful receipt of data. Such acknowledgments (ACKs) generate additional network traffic, diminishing the rate at which data passes in favor of reliability. To reduce the impact on performance, most hosts send an acknowledgment for every other segment or when a specified time interval has passed.

Acknowledge character (ACK) — A transmission control character transmitted by the receiving station as an affirmative response to the sending station. Note: An acknowledge character may also be used as an accuracy control character.

Aconsole — A NetWare 3.1x utility used for remote management using an asynchronous link. It controls the transfer of screen and keystroke information to and from the remote file server.

Across-the-Wire Migration — An upgrade method using migration utility MIGRATE.EXE to upgrade an existing 2.1x, 2.2, or 3.1x server to 4.1. This utility can also upgrade IBM PCLP 1.3 Extended Services; IBM LAN Server 1.0, 1.1, 1.2, 1.3; and Microsoft LAN Manager 2.0 to NetWare 4.1. For this method, three computers are needed: the existing server (source server); the destination server; and DOS client running NetWare client software, with a local hard disk.

Active — A window is active when it is on the top of the desktop and its title bar is highlighted. This term can be applies to the window or icon itself that you are currently using or that is currently selected. Windows NT always applies the next keystroke or command you choose to the active window. If a window is active, its title bar changes color to differentiate it from other windows. If an icon is active, its label changes color. Windows or icons on the desktop that are not selected are inactive.

Active Channel — A Web site that automatically delivers content to a user’s computer on a regular schedule

Active Desktop — An interface that integrates the Windows desktop with the Internet Explorer browsing software to provide a single metaphor for accessing content or applications

Active Monitor — One station in a ring topology that performs ring maintenance functions such as removing the frame that the original node has failed to remove, etc.

Active Setup — An application that collects information about the user’s computer before download of Internet Explorer begins, and then uses this information to manage the download intelligently

Active Window — The window that accepts entries and commands; this window is shown with a solid title bar and is normally the top window.

ActiveX — An umbrella term for Microsoft technologies that enable developers to create interactive content for the World Wide Web. A set of language-independent interoperability technologies that enable software components written in different languages to work together in networked environments. The core technology elements of ActiveX are COM and DCOM

Adapter Cable — A type of cable used in a Token Ring network to connect the workstation to the MSAU (Multistation Access Unit).

Adapter card — circuit board or other hardware that provides the physical interface from a PC, workstation or other equipment to the communications network; See network card.

Adapter segment — A name sometimes used for the upper memory area, at hexadecimal addresses A000 through EFFF (640K to 1024K).

Add Self Right — A property right to add a new property value or delete an existing one.

Add-on Board — A circuit board that can be added to increase the capabilities of a personal computer, for example, a memory board for extending the amount of RAM.

Address — A number that uniquely identifies the location of a computer resource; When using Network Monitor, an address refers to a hexadecimal number that identifies a computer uniquely on the network.

Address class — Predefined groupings of Internet addresses, with each class defining networks of a certain size. The range of numbers that can be assigned for the first octet in the IP address is based on the address class. Class A networks (values 1-126) are the largest, with over 16 million hosts per network. Class B networks (128-191) have up to 65,534 hosts per network, and Class C networks (192-223) can have up to 254 hosts per network. See also octet.

Address pairs — Refers to the two specific computers between which you want to monitor traffic using Network Monitor. Up to four specific address pairs can be monitored simultaneously to capture frames from particular computers on your network. See also frame.

Address resolution protocol (ARP) — A Transmission Control Protocol/Internet Protocol (TCP/IP) protocol that dynamically binds a Network-Layer IP address to a Data-Link-Layer physical hardware address, e.g., Ethernet address. It is used for determining a host's Ethernet address from its Internet address. Part of the TCP/IP suite it provides IP address-to-MAC address resolution for IP packets. See also media access control (MAC); IP address; packet.

Addressing disk channel — Number assignment technique for identifying hardware resources on disk channels.

Addressing Space — The total amount of RAM in a NetWare server that is available to the operating system, and this amount can be divided into segments.

Administrative account — An account that is a member of the Administrators local group of a computer or domain.

Administrative alerts — Administrative alerts relate to server and resource use and warn about problems in areas such as security and access, user sessions, server shutdown due to power loss (when UPS is available), directory replication, and printing. When a computer generates an administrative alert, a message is sent to a predefined list of users and computers. See also Alerter service; UPS.

Administrator — A person responsible for setting up and managing domain controllers or local computers and their user and group accounts, assigning passwords and permissions, and helping users with networking issues. To use administrative tools such as User Manager or User Manager for Domains, an administrator must be logged on as a member of the Administrators local group of the computer or domain, respectively.

Administrator privilege — One of three privilege levels you can assign to a Windows NT user account. Every user account has one of the three privilege levels (Administrator, Guest, and User). See also administrator; User privilege and Guest privilege.

Advanced Configuration and Power Interface (ACPI) — A system interface that provides a standard way to control power management and Plug and Play functions of the computer hardware. ACPI allows the computer motherboard to describe its device configuration and power control hardware interface to Windows 95(8). This allows the operating system to automatically turn on and off standard devices, such as CD-ROMs, network cards, hard disk drives, and printers, as well as consumer devices connected to the computer, such as VCRs, TVs, phones, and stereos

Advanced Power Management (APM) — A software interface (defined by Microsoft and Intel) between hardware-specific power management software (such as that located in a system BIOS) and an operating system power management driver

American Standard Code for Information Interchange (ASCII) — A character code published by the American National Standards Institute (ANSI) in which each character is represented by a unique 7-bit pattern.

AFP Server Object — A leaf object used to represent an AppleTalk Filing Protocol server on your network.

Agent — In SNMP, agent information consists of comments about the user, the physical location of the computer, and the types of service to report based on the computer’s configuration. See also SNMP.

Alarm Thresholds — A feature of LANalyzer that can be set according to your network base-line to notify you of any unusual activity that might indicate a problem.

Alerter service — Notifies selected users and computers of administrative alerts that occur on a computer. Used by the Server and other services. Requires the Messenger service. See also administrative alerts; Messenger service.

Algorithm — A mathematical step-by-step problem-solving procedure, especially an established, recursive computational procedure for solving a problem in a finite number of steps. All programs apply this concept in mathematics to provide a computer its instructions.

Alias Object — A leaf object used to point to another object in the NDS tree. The object pointed to may be a leaf or container.

Alloc Short-Term Memory — Memory used for short-term memory requests. Alloc memory is used by loadable modules with pop-up windows (such as INSTALL or MONITOR) to store previous menu information.

Allocated Memory Pool — Memory value in the Server Memory Statistics that shows how much memory is reserved for NLMs for data. Values are given both in bytes and in percentages (of total server work memory).

ALLOW — A NetWare 3.1x command used to view, set, or modify the Inherited Rights Mask (IRM) of a directory or a file.

Allow Unencrypted Passwords — If this SET parameter is ON, the users can use both encrypted and unencrypted passwords. If this parameter is OFF, they can use only encrypted passwords.

Amplitude — The instantaneous value of an analog signal at any time. Amplitude (strength or loudness) is measured in volts (electrical or electromagnetic wave), watts (electrical power), amps (electrical current), or decibels (the ratio between the powers of two signals).

Amplitude Modulation — Conversion of the voltage level or the amplitude of a carrier frequency for analog or digital data transmission.

Analog Data — A type of data that can take continuous values (any values in a range). For example, voice and video are continuously varying patterns of intensity.

Analog Signals — Continuously varying electromagnetic waves that may be propagated (transmitted) over wires and through the atmosphere or space.

ANSI (American National Standards Institute) — A voluntary, U.S. based standards-setting organization for the information processing industry.  This member of the ISO published the ASCII standard.

API — An abbreviation for application programming interface, which is a set of routines that an application program uses to request and carry out lower-level services performed by the computer’s operating system. For Windows, the API also helps applications manage windows, menus, icons, and other GUI elements. For a local area network, an API provides applications with routines for requesting services from lower levels of the network. See application programming interface

AppleShare — Client software that is shipped with all Macintoshes and with Apple Computer’s server software. With Services for Macintosh, Macintoshes use their native AppleShare client software to connect to computers running Windows NT Server that have Services for Macintosh.

Applet — (1) A small application that serves as a component of a larger application. (2) An HTML-based program built with Java that a browser temporarily downloads to a user's hard disk, from which location it runs when the Web page is open

AppleTalk — Apple Computer’s network architecture and network protocols. A network that has Macintosh clients and a computer running Windows NT Server with Services for Macintosh functions as an AppleTalk network.

AppleTalk Filing Protocol — The presentation layer protocol that manages access of remote files in an AppleTalk network.

AppleTalk Phase 2 — The extended AppleTalk internet model designed by Apple Computer, which supports multiple zones within a network and extended addressing capacity.

AppleTalk Protocol — The set of network protocols on which AppleTalk network architecture is based. Setting up Services for Macintosh installs its AppleTalk Protocol stack on a computer running Windows NT Server so that Macintosh clients can connect to it.

AppleTalk Transport — The layer of AppleTalk Phase 2 protocols that deliver data to its destination on the network.

Application — A computer program (software) used for a particular kind of work. Generally, these are large software packages you can use to perform specific functions such as word processing, Web browsing, or database management. Applications typically consist of more than one program, although the word "application" is often used interchangeably with the word "program".

Application Directory — Directory for applications. No user-created files should be stored under this directory.

Application Icon — The icon of a running application.

Application layer — The 7th layer of the OSI (Open Systems Interconnection) that interfaces with User mode applications by providing high-level network services based upon lower-level network layers. Network file systems like named piped are an example of Application layer software. It is concerned with application programs such as electronic mail, database managers, and file-server software.

Application log — The application log contains specific events logged by applications. Applications developers decide which events to monitor (for example, a database program might record a file error in the application log). Use Event Viewer to view the application log.

Application Program Interface (API) — A set of routines that an application program uses to request and carry out lower-level services performed by the operating system. Its functions are used by software developers to design applications for a particular platform. This could include a collection of programming routines that take advantage of an operating system’s features. This gives an "interface" to the operating system for the "application". Windows 95 and NT use the WIN32 API. A Network API may be referred to as a socket interface.

Application Services — Network services typically provided by a dedicated application server that runs software for clients. Application servers are different from file servers because they run applications and process data for clients instead of just allowing them to share data.

Application Window — The window within which an application such as Word or Excel run. The main window for an application, which contains the application's menu bar and work area. An application window may contain multiple document windows.

ARC — Acronym for Advanced RISC Computing. ARC names are a generic method of identifying devices within the ARC environment. See also RISC.

Architecture — The structure of all or part of a computer system. Also refers to the design of system software

Archive — Transfer of files to long-term storage devices, for example, to a magnetic tape.

Archive bit — Backup programs use the archive bit to mark the files after backing them up, if a normal or incremental backup is performed. See also backup types.

ARCnet — Attached Resource Computer Network. A simple and reliable network architecture (Network Interface Card (NIC)) for LANs developed by Datapoint Corporation. ARCnet, designed as a token-passing bus architecture, provides 2.5 Mbps speed and supports coax Rg-62 A/U (93 Ohm), Unshielded Twisted Pair (UTP), and fiber optic cables in bus and star topologies. In star topology, it uses active and passive hubs.

ARCnet Plus — A 20 Mbps version of ARCnet. It is backward compatible with ARCnet and uses the same coax cable.

Area Boundary Router — A router that connects an area to the backbone. Routers within an area receive routing information about the rest of the network through the

Areas — Smaller contiguous networks within a large internetwork to further limit the amount of routing information flowing in the network (or internetwork).

ARM above 16 MB — Auto Register Memory above 16 Megabytes. A memory parameter that controls the automatic registering of memory above 16MB in EISA computers and can only be changed in the STARTUP.NCF file.

ARP — Address Resolution Protocol. Internet layer maintenance protocol that is used by a host to find out the hardware address of a destination host using the destination host's IP address. It translate a host's software address (IP address) to a hardware address (MAC address). See also TCP/IP.

ARP reply packet — All ARP-enabled systems on the local IP network detect ARP request packets, and the system that owns the IP address in question replies by sending its physical address to the requester in an ARP reply packet. The physical/IP address is then stored in the ARP cache of the requesting system for subsequent use. See also ARP; ARP request packet; IP; MAC address.

ARP request packet — If two systems are to communicate across a TCP/IP network, the system sending the packet must map the IP address of the final destination to the physical address of the final destination. This physical address is also referred to as a MAC address, a unique 48-bit number assigned to the network interface card by the manufacturer. IP acquires this physical address by broadcasting a special inquiry packet (an ARP request packet) containing the IP address of the destination system. See also ARP; IP; MAC; MAC address.

AS — Autonomous System. A group of routers that exchange routing information using a common routing protocol.

AS/400 — A type of IBM minicomputer.

ASBR Autonomous System Border Router — A router that connects an AS with another (external) AS. It broadcasts routes that can be reached via the AS to the external networks, and at the same time, it provides external routing information to the routers in the AS.

ASCII (American Standard Code for Information Interchange) — A widely used 7-bit code-set established by ANSI used as a standard code for representing characters to achieve compatibility between products manufactured by different companies.

ASCII file — Also called a text file, a text-only file, or an ASCII text file, refers to a file in the universally recognized text format called ASCII (American Standard Code for Information Interchange). An ASCII file contains characters, spaces, punctuation, carriage returns, and sometimes tabs and an end-of-file marker, but it contains no formatting information. This generic format is useful for transferring files between programs that could not otherwise understand each other’s documents. See also text file.

ASPI — Advanced SCSI Programming Interface

Associate — To identify a filename extension as "belonging" to a certain application, so that when you open any file with that extension, the application starts automatically.

Asymmetrical Multiprocessing — A multiple process architecture in which certain threads or in which scheduling is not done on a fair-share basis. Asymmetrical multiprocessing is easier to implement than symmetrical multiprocessing, but does not scale well as processors are added.

Asynchronous Bit Synchronization — A method of bit synchronization in which the transmitter sends a start bit to begin transmission. When the receiver identifies a start bit, it begins an internal clock and continues measuring the signal at predetermined bit intervals until the transmitter sends a stop bit.

Asynchronous Link — A communication link method where a remote session is established using a modem. A user does not have to login to a file server.

AT-ADAPT-2 — a harmonic-style adapter that allows direct conversion from a 50-pin Telco connector to RJ45 receptacles.

ATM — Asynchronous Transfer Mode. An emerging packet-switching standard that provides very high bandwidths (155.52 Mbps to 2.488 Gbps) for a variety of traffic (voice, data, video) over LAN/MAN/WAN. This new type of cell switching technology uses fixed-length packets to transmit data from source to destination. ATM uses fixed-length 53-byte cell-switching to transmit data, voice and video over both LANs and WANs. Also referred to as BISDN and Cell Relay.

ATOTAL — A NetWare command used to total the accounting services usage on a network. Accounting services must be installed on the file server before you use this command.

ATPS — AppleTalk Print Services. Allows Macintosh clients to print to a NetWare queue and non-Macintosh clients to an AppleTalk printer.

ATTACH — A NetWare command used to connect the workstation to multiple file servers.

Attenuation — A decrease in the power of a signal.

Attribute — A characteristic or property; for example, the color of a line, the length of a data field, or a typeface characteristic such as size.

Attributes — Information that indicates whether a file is a read-only, hidden, system, or compressed file, and whether the file has been changed since a backup copy of it was made. In NetWare, attributes are special properties of files and directories that enable or disable operations on files and directories. Attributes override rights.

AUD$HIST.DAT — A binary file kept at the root of each volume that is used to keep track of the auditor's activities.

Audit policy — For the servers of a domain or for an individual computer, defines the type of security events that will be logged.

AUDITCON — A NetWare 4 menu utility used at workstation to audit transactions on a network. It is used to make sure that confidential information is secure.

Auditing — A means of tracking users and events, such as when a specific file or directory was accessed and by whom, when the volume was mounted or server was downed and by whom, the creation or deletion of print queues, and other changes in the NDS tree.

AUI (Attachment Unit Interface) — the branch cable interface located between a MAU (transceiver) and a DTE (typically a workstation). Includes a 15-pin D-sub connector and sometimes a 15-conductor twisted pair cable. Maximum length is 50 meters (164 ft.).

Authentication — Validation of a user’s logon information. When a user logs on to an account on a computer running Windows NT Workstation, the authentication is performed by that workstation. When a user logs on to an account on a Windows NT Server domain, authentication may be performed by any server of that domain. See also server; trust relationships. This technology makes it possible to identify who published a piece of software and verify that it has not been tampered with. In NetWare, a background process that verifies that the requests to NDS are coming from a valid user (or any other valid object).

Auto Load — Printer location that is local to the print server and is connected directly to the print server.

AUTO RECONNECT — NET.CFG parameter that automatically reconnects a workstation to a NetWare server and rebuilds the workstation's environment (excluding file specific items) existing prior to losing the connection. Default is ON.

AUTO RETRY — NET.CFG parameter to set the time (in seconds) that AUTO.VLM waits before attempting a retry after receiving a network critical error.

AUTO.VLM — A VLM that automatically reconnects a station to a server.

AUTOEXEC.BAT — A DOS file which is used to automatically execute commands whenever a user boots a workstation.

AUTOEXEC.NCF — A server configuration file in the SYS:SYSTEM directory that stores the server name and internal network number, loads the LAN drivers and settings for the network boards, and binds the protocols to the installed drivers.

Automatic proxy configuration file — A file that dynamically assigns browser proxy settings based on the location of hosts.

Automatic Rollback — Transaction Tracking System (TTS) feature that returns back a database to its most recent complete state when a network running under TTS fails during a transaction. This prevents corruptions from incomplete transactions.

Auto-sense — A feature of network devices that may be used on networks that use multiple transmission types and speeds. Auto-sense determines another device's transmission speed and other settings and then uses the corresponding settings to communicate. Many switches and high-speed hubs tout 10/100 autosense abilities. While this option works sometimes, with some network cards, it can fail. 10/100 network cards often have autosense, but inferior or problematic cabling can make a card detect at 100 Mbps at one time and 10 Mbps at another.