Backbone — (1) The central cabling system where servers and routers are attached. It provides connections to other cable segments, and it manages the mass of the network traffic.  More generally, it can refer to any network considered to provide interconnection among subnetworks. (2) A high-speed cable joining together several network bridges, or possibly used to connect 2 or more stations.

Backfilling — To designate memory on an expanded memory card and make it available for use as conventional memory.

Backup Always — A duplicate of data and/or programs on a storage media (e.g. hard disk and floppy disks) that is retrievable in case the original data is destroyed.

Backup Domain Controller (BDC) — In a Windows NT Server domain, a computer running Windows NT Server that receives a copy of the domain's directory database, which contains all account and security policy information for the domain. The copy is synchronized periodically and automatically with the master copy on the primary domain controller (PDC). BDCs also authenticate user logons and can be promoted to function as PDCs as needed. Multiple BDCs can exist on a domain. See also member server; PDC.

Backup Module — A repeater that behaves as the management module when the Master fails in a department concentrator.

Backup set — A collection of files from one drive that is backed up during a single backup operation.

Backup set catalog — At the end of each backup set, Windows NT Backup stores a summary of file and/or directory information in a backup set catalog. Catalog information includes the number of tapes in a set of tapes as well as the date they were created and the dates of each file in the catalog. Catalogs are created for each backup set and are stored on the last tape in the set. See also backup set.

Backup set map — At the end of each tape used for backup, a backup set map maintains the exact tape location of the backup set’s data and catalog.

Backup types: copy backup — Copies all selected files, but does not mark each file as having been backed up. Copying is useful if you want to back up files between normal and incremental backups, because copying will not invalidate these other backup operations.

Bandwidth — The capacity of the transmission media. A signal can be transmitted along the transmission media by using the media’s total bandwidth or by using a part of it. In communications, the difference between the highest and lowest frequencies in a given range, expressed in Hz (hertz). For example, a telephone line accommodates a bandwidth of 3000 Hz, the difference between the lowest (300Hz) and highest (3300 Hz) frequencies it can carry. In computer networks, greater bandwidth indicates faster data-transfer capability and is expressed in bits per second (bps).

Bank switching — A technique for sequentially reading page frames in expanded memory. The 64K page frames are brought into the upper memory block from an expanded memory card, then read and swapped back to the card so that the next 64K page frame can be brought in.

Base Input/Output (I/O) Port — Specifies a channel through which information is transferred between your computer's hardware (such as your network card) and its CPU. The port appears to the CPU as an address.

Base Memory Address — Reserved area in PC memory for RAM on-board to buffer incoming or outgoing packets.

Base memory address — Defines the address of the location in your computer’s memory (RAM) that will be used by the network card to exchange information between your computer and the other computers you are connected to. This setting is sometimes called the RAM start address.

Baseband — A method of transmitting signals along the transmission medium related to bandwidth that uses digital signaling. Digital signals are inserted on the line as voltage pulses. The Baseband system can transmit multiple signals by combining them into one signal and then transmitting them using one channel.

Baseband — A signaling technique in which the signal is transmitted in its digital form and not changed by modulation techniques.

Basic Input/Output System (BIOS) — A set of routines in firmware that provides that provides the most basic software interface drivers for hardware attached to the computer. The BIOS contains the first level of booting.

Basic MHS — An entry level product to the world of E-Mail. It is limited to a single file server, but is upwardly compatible to the more advanced Global MHS product from Novell.

Batch File — A file with the extension BAT that contains a sequence of DOS-type commands that are executed when the name of the batch file is entered.

Batch program — An ASCII file (unformatted text file) that contains one or more Windows NT commands. A batch program’s filename has a .cmd or .bat extension. When you type the filename at the command prompt, the commands are processed sequentially.

Batch queue facility — A program that effects a logon without user input, used for delayed logons.

Baud Rate — The signal modulation rate, or the speed at which a signal changes in serial communication.

BDC — See backup domain controller.

Beaconing — The process of informing that a failure or fault domain of token passing has occurred by a node in a Token Ring network to other nodes in the network. A beacon packet includes the sending computer address, its NAUN address, and the type of beacon.

Beaconing Problem — A typical Token Ring error that occurs when a workstation does not receive a seven-second greeting from its nearest active upstream neighbor (NAUN), so it starts sending a beacon packet.

Bezier curve — A mathematical construct for describing a curve, used in CAD and illustration software to draw complex graphic shapes.

Binary — A number system based on two digits (0,1) that serves as the basis for all computer code. This number system is appropriate for electronics since an electrical current is either on or off. 1 represents on and 0 represents off.

Binary-file transfer — A method of transferring binary files from Windows NT HyperTerminal to a remote computer. Binary files consist of ASCII characters plus the extended ASCII character set. These files are not converted or translated during the transfer process. See also ASCII file.

BIND RECONNECT — NET.CFG parameter that automatically rebuilds bindery connections and restores drive mappings and printer connections.

Bindery — A database in which NetWare 3.1x stores the security information about users, groups, and other objects.

Bindery Context — Container object where bindery services are kept.

Bindery Context Path — A path statement allowing bindery context to be set up to 16 containers.

Bindery Data Sets — A component of bindery, it is the values assigned to the bindery object's properties.

Bindery Emulation/Bindery Services. — A feature that allows workstations to access a NetWare 4.1 server using the old NetWare DOS shell (NETx). By default, bindery emulation is enabled on the Directory tree, and bindery context is set to the container in which your server is created.

Bindery Object — A component of bindery, it is a user, group, print server, file server, or any other entity that has been given a name. NetWare assigns a unique ID number for each bindery object.

Bindery Properties — A component of bindery. It is the characteristics associated with bindery object. Examples include passwords, account restrictions, account balances, groups the user belongs to, etc.

Bindery Queue Object — A leaf object representing a print queue in the NDS tree. It is created by the 4.1 update or migration process.

Bindery Services — A NetWare 4 feature that allows all objects within the specified container’s bindery context to be accessed by NDS objects as well as by bindery-based servers and bindery-based clients.

Bindery Synch Cluster — The NetWare 4.1 server and the attached NetWare 3.1x servers.

Bindery Synchronization — NetWare 4.1 feature that allows you to combine bindery information of up to 12 NetWare 3.1x servers with NetWare 4.1 NDS.

BINDFIX — Used to correct problems with the NetWare 3.1x bindery files.

Binding — The process of assigning a communication protocol to network boards and LAN drivers, so the LAN drivers can process packets, a process during which a protocol driver and a MAC driver exchange information, via the NDIS interface library, about identities, capabilities, function addresses, and binding context. It can be thought of as the process of linking network services to network service providers. The binding facility allows users to define exactly how network services operate in order to optimize the performance or the system. By default, Windows enables all possible bindings. The Network control panel is used to change binding. See also network card; TCP/IP.

BINDREST — A NetWare 3.1x command used to restore old version of the bindery files after BINDFIX has been run.

BIOS — An acronym for basic input/output system, which is software (usually contained in ROM). It is a set of routines that works closely with the hardware to support the transfer of information between elements of the system, such as memory, disks, and the monitor

BIOS Parameter Block (BPB) — Information located inside the boot sector specific to the logical drive information

Biphase Coding Technique — Technique of encoding digital data in digital signals that requires at least one transition per bit time. It is self-clocking, and error detection is easier

Bipolar — A scheme used for encoding digital data in digital signals in which signals vary between three levels: positive, 0, and negative voltages. This coding is not self-clocking.

Bit (b) — A binary digit. A numeral having only two possible values, 0 or 1. Computers represent these two values as high (on, voltage present) or low (off, no voltage present) state on a control line.

Bit Rate (BR) — The rate of data throughput on the medium in bits per second. Ethernet specifies 10 million bits per second.

Bit Synchronization — A process of accurately determining the duration of each bit (bit time). Both the transmitter and receiver must be in synchronized to determine when one bit ends and another begins.

Bit Time — The duration of one bit symbol (1/BR). Ethernet specifies a bit time of 100 ns.

Bitmap — A sequential collection of bits that represents, in memory, an image to be displayed on the screen.

Bit-oriented Protocol — A protocol for data transmission that moves one bit of data at a time regardless of the meaning of the bit.

Block device — A device such as a disk drive that moves information in groups of bytes (blocks) rather than one byte at a time

Block Sub-allocation — It allows the disk blocks to be allocated in smaller units.

BNC Connector — A specific type of connector used for coaxial RG58 cable connection.

Bookmarks — A Windows NT feature which enables you to highlight major points of interest at various points in a Performance Monitor log file and then return to them easily when you work with that log file later on during performance monitoring. Bookmarks are also used in other applications such as Microsoft Word.

Boot — The process of loading a computer’s operating system. (Also called a bootstrap.) Booting usually occurs in multiple phases, each successively more complex until the entire operating system and all its services are running.  Sometimes this term is used for the files used to start the operating system and its drivers, load NetWare, and set environment variables. Examples of these files are AUTOEXEC.BAT and CONFIG.SYS.

Boot loader — Defines the information needed for system startup, such as the location for the operating system’s files. Windows NT automatically creates the correct configuration and checks this information whenever you start your system.

Boot partition — The volume, formatted for either an NTFS or FAT file system, that has the Windows NT operating system and its support files. The boot partition can be (but does not have to be) the same as the system partition. See also partition; FAT; NTFS.

Boot sector — First sector on a logical drive that includes code to boot that drive, specific logical drive information, and error messages

BOOTP — Internet layer that determines IP addresses, server address, and filenames to be loaded and executed at boot time (usually used by a diskless workstation). BOOTP is used as an alternate to RARP. See Bootstrap protocol.

Bootstrap protocol (BOOTP) — A TCP/IP network protocol, defined by RFC 951 and RFC 1542, used to configure systems. DHCP is an extension of BOOTP. See also DHCP.

Bps — An abbreviation for bits per second, a measure of the speed at which a device, such as a modem, can transfer data.

Branch — A segment of the directory tree, representing a directory (or folder) and any subdirectories (or folders within folders) it contains.

Branch Cable — The AUI cable interconnecting the DTE and MAU system components also known as a Drop cable.

BREAK ON/OFF — A login script command to abort the execution of your login script. Default is OFF.

BRGCON — A NetWare 4 loadable module used to view objects implemented through SNMP on a NetWare bridge.

Bridge — A LAN interconnection device used to link two or more local or remote LANs. Bridges are used extensively in LAN systems to extend their physical dimensions or modify their performance. This filter and forwarding device operates at the Data-Link layer of the OSI model. It has access to the station’s physical address and can determine the source and destination involved in the transfer, as well as, permitting or denying access to the new segment based on this address. In a bridged network, there can be only one path to any destination (otherwise packets would circle the network, causing network storms). A bridge is more sophisticated than a repeater, but not as sophisticated as a router. See also packet; repeater; router; subnet.

Bridge MIB — A specification that defines an experimental portion of the Management Information Base for use with network managing protocols in TCP/IP based internets. In particular, it defines objects for managing bridges based on the IEEE 802.1d draft standard between LAN segments.

Broadband — A method of transmitting signals along the transmission medium related to bandwidth that uses analog signaling. Broadband systems can divide the media’s entire bandwidth into multiple channels which can carry multiple signals (voice, video, and data) at the same time. This allows many more bits per unit of time to be moved from point to point. services provided include video, voice, and additional data channels.

Broadband ISDN — An enhanced ISDN specification that was developed to provide high data rates for voice, data, and video transmission. B-ISDN interfaces provide data rates of 51 Mbps, 155 Mbps, or 622 Mbps over fiber optic media.

Broadcast — In general terms, a transmission sent simultaneously to more than one recipient. In Internet terminology, a transmission sent to a single address to be forwarded to many recipients. In practice, Internet broadcasts function only on local networks, because routers do not forward them

Broadcast client — A versatile personal computer that can receive and display broadband digital and analog broadcasts, blending television with new forms of information and entertainment. Broadcast client programming can include television, audio, World Wide Web pages, and computer data content

Broadcast datagrams — An IP datagram sent to all hosts on the subnet. See also datagram; Internet Protocol (IP); subnet.

Broadcast domain — A segment of a network where all nodes receive broadcast messages.

Broadcast message — A network message sent from a single computer that is distributed to all other devices on the same segment of the network as the sending computer.

Broadcast name resolution — A mechanism defined in RFC 1001/1002 that uses broadcasts to resolve names to IP addresses through a process of registration, resolution, and name release. See also broadcast datagram; IP address.

Broadcast server — A computer that sends broadcast programming across a broadcast channel to broadcast clients. The programming sent can include television, audio, World Wide Web pages, and digital data such as stock prices, multimedia magazines, and computer software

Brouter — Combines elements of the bridge and the router. A Brouter first checks a packet to see if it supports the packet’s Network layer protocols. If not, the packet is only bridged using layer 2 (Data-Link layer) information. Usually, a brouter acts as a router for one transport protocol (such as TCP/IP), sending packets of that format along detailed routes to their destinations. The brouter also acts as a bridge for all other types of packets (such as IPX), just passing them on, as long as they are not local to the LAN segment from which they originated. See also bridge; packet; router.

Browse — To view available network resources by looking through lists of folders, files, user accounts, groups, domains, or computers. Browsing allows users on a Windows NT network to see what domains and computers are accessible from their local computer. See also Windows NT browser system.

Browse list — A list kept by the master browser of all of the servers and domains on the network. This list is available to any workstation on the network requesting it. See also browse.

Browse master — See master browser; Windows NT browser system.

Browse Right — An object right to view the objects in the NDS tree. It is similar to the file system file scan right.Temporary storage location in a computer’s memory.

Browser — (1) A computer on a Windows network that maintains a list of computers and services available on the network.
(2) A client tool for navigating and accessing information on the Internet or an intranet. A browser interprets hypertext markup language (HTML) and displays information on a computer screen. A popular example is Microsoft Internet Explorer

Browsing — The process of requesting the list of computers and services on a network from a browser. In Windows, Network Neighborhood provides graphical access to the browse list of your network.

Buffer — A reserved portion of memory in which data is temporarily held pending an opportunity to complete its transfer to or from a storage device or another location in memory. Some devices, such as printers or the adapters supporting them, commonly have their own buffers. See also memory.

Buffer Bits — Bits with zeroes. An electronic channel along which signals are sent from one part of a computer to another.

Buffer descriptor — A data structure containing information about a buffer, such as a pointer to the buffer's physical location, number of bytes, and size. It does not include the actual data in the buffer.

Buffering — The process of using buffers to hold data being moved to or from I/O devices such as serial ports and disk drives.

Buffers — A reserved part of memory where data is held temporarily until the data is transferred from storage to another location in memory. Some printers have their own buffers.

Built-in groups — Are default groups provided with Windows NT Workstation and Windows NT Server which have been granted useful collections of rights and built-in abilities. In most cases, a built-in group provides all the capabilities needed by a particular user. For example, if a domain user account belongs to the built-in Administrators group, logging on with that account gives a user administrative capabilities over the domain and the servers of the domain. To provide a needed set of capabilities to a user account, assign it to the appropriate built-in group. See also groups, User Manager, User Manager for Domains.

Bus — A channel for passing electronic signals from one part of the computer to another or any hardwire lines used for data transfer among the components of a computer system

Bus class driver — In Windows 95(8), a driver that provides an interface between the hardware layer and bus minidrivers

Bus enumerator — A driver is responsible for creating the Windows 95(8) hardware tree

Bus Topology — A physical network topology in which all devices on the network are attached to a single cable called the bus.