Network Terms "B"

Network Glossary and acronym's

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Back end

The server where database operations occur. The back end fulfills client requests by receiving structured requests from the client, processing the requests, and returning the results. It is usually more powerful than the client.

Backbone area

A backbone area acts as a hub for inter-area transit traffic and the distribution of routing information between areas. All OSPF networks have at least one backbone area, also known as an area 0.

Backbone router

A backbone router is located in the perimeter of the backbone area. Backbone routers:

Maintain OSPF routing information using the same procedures and algorithms as internal routers.
Have at least one interface that is connected to area 0.

Backup Designated Router (BDR)

On each subnet, a single OSPF router is identified as the Backup Designated Router (BDR). The BDR becomes the Designated Router (DR) if the DR becomes unavailable.

Backup Domain Controller (BDC)

A server containing a replicated copy of the domain database. Each Windows NT domain will have one PDC (Primary Domain Controller) with zero or more BDCs (backup domain controllers).

Backup log

A text file that records backup operations. The log is helpful when restoring data. You can print it or read it in a text editor.

Backup marker

Windows Backup can set a backup marker, also known as the archive attribute, indicating that the file has been backed up.

Backup Operators

A group that has permission to perform backups on a system. This group should have only sufficient rights to perform a backup. They typically use the Windows backup software.

Backup set

A term used to describe a group of files or folders on a single volume from a single backup operation. A group of tapes is called a family set.

Baseband

Baseband signaling allows one signal at a time on the network medium (cabling).

Baseline

A server baseline is a snapshot of the performance statistics of your server that is used as a logical basis for future comparison. Server baselines enable you to effectively monitor the performance of your system to determine when changes negatively impact performance or when systems need upgrading or replacing.

Baselining

Documenting a network's average performance statistics over time.

Basic authentication

An authentication method that requires the user to enter a valid username and password for a Windows user account. This information passes between the server and client in clear text.

Basic disk

A physical disk containing primary partitions, extended partitions, or logical drives. Using Windows NT 4.0 or earlier, you can create RAID-5 volumes for basic disks; they can also be spanned, mirrored, or part of a stripe set. MS-DOS can access basic disks. Compare dynamic disk.

Basic multicast

Basic multicast supports multicast applications within an enterprise campus. It is an interactive, intra-domain form of multicast that provides integrity within a network when combined with a reliable multicast transport such as PGM.

Batch file

A set of commands used to perform a specific operation on a computer.

Baud rate

The number of bits per second that are physically signaled over a communication medium. The term "baud" originally referred to the number of dots per second that could be signaled using Morse code over particular telegraph systems. The unit of measure was named after J.M.E. Baudot, the developer of the first printer for telegraph systems.

BDC (Backup Domain Controller)

A server containing a replicated copy of the domain database. Each Windows NT domain will have one PDC (Primary Domain Controller) with zero or more BDCs (backup domain controllers).

BDR (Backup Designated Router)

On each subnet, a single OSPF router is identified as the Backup Designated Router (BDR). The BDR becomes the Designated Router (DR) if the DR becomes unavailable.

Best information

Using the split horizon method (also called best information), routers keep track of where the information about a route came from. Routers do not report route information to the routers on that path. In other words, routers do not report information back to the router from which their information originated.

BGP (Border Gateway Protocol)

Border Gateway Protocol (BGP) is a policy-based, interautonomous system routing protocol that exchanges reachability information with other BGP systems.

BGP Address Family Identifier (AFI)

The Cisco BGP Address Family Identifier (AFI) model was introduced with multiprotocol BGP. It is designed to be scalable and modular, and to support multiple AFI and Subsequent Address Family Identifier (SAFI) configurations.

BGP attributes

BGP attributes are used to select the best path to be entered into the routing table and propagated to the BGP neighbors. BGP attributes can be well-known mandatory, well-known discretionary, optional transitive, or optional nontransitive. The following definitions are used to define BGP attributes:

Well-known attributes are standard. All implementations of BGP support standard attributes.
- Well-known mandatory attributes have to be present in all implementations of BGP.
- Well-known discretionary attributes are implemented according to the needs of individual implementations of BGP.
Optional attributes are non-standard, meaning they are specific to particular implementations of BGP.
- Optional transitive attributes are transmitted between two or more autonomous systems.
- Optional nontransitive attributes remain in a single autonomous system.

BGP peer

A BGP peer (also called a neighbor) is a BGP speaker that is configured to form a neighbor relationship with another BGP speaker. Neighbor relationships allow BGP speakers to directly exchange BGP routing information with one another.

BGP peer group

A BGP peer group consists of the neighbors of a router that is being configured. All routers in a BGP peer group have the same update policies; thus allowing updates to be generated only once for the entire peer group.

BGP speaker

A BGP speaker is any router that runs BGP.

BGP synchronization rule

The BGP synchronization rule states that a BGP router cannot use or advertise a route that it has learned from internal BGP (iBGP) to an external neighbor unless it has also been established through an internal gateway protocol, such as RIP or OSPF.

Bidirectional PIM

Bidirectional PIM explicitly builds shared bi-directional trees. Bidirectional PDM:

Never builds a shortest path tree.
May have longer end-to-end delays than PIM-SM.
Is scalable because it needs no source-specific state.

Binary compatible

An application that runs on any Windows-supported platform, not only on the hardware for which it was originally compiled.

Binary Synchronous Communications Protocol (BISYNC)

A Data Link layer protocol for synchronous communication devices.

Bindery

The system that networks running Novell NetWare use to validate user accounts and passwords. It is the equivalent of the directory database in Windows NT.

Binding

The process of assigning services to network components.

BISYNC (Binary Synchronous Communications Protocol)

A Data Link layer protocol for synchronous communication devices.

Bit

The smallest unit of data a computer uses. A bit is a binary value, either a 0 or a 1.

Bluetooth

A proposed standard of the IEEE 802.15 committee, designed to allow people to connect in PAN (personal area network) configurations using cell phones, PDAs (personal digital assistants), printers, mice, keyboards and other Bluetooth equipped devices.

B-node

A type of broadcast used by NetBIOS over TCP/IP. The B-node uses UDP datagrams to broadcast for name registration and resolution. B-node broadcasts are usually not forwarded by routers, and only computers on the local network can respond.

Body parts

Body parts are the codes for the text, data, and other information included in an e-mail message.

Boot disk

A floppy disk containing an operating system that is used to boot up a PC in the absence of the PC's operating system.

Boot partition

The partition on a hard drive where the Windows operating system files reside.

Boot.ini

A file that builds the Boot Loader Operating System Selection menu. The screen that is displayed is known as the boot loader screen and allows a user to select an operating system from the screen. If no selection is made, NTLDR loads the operating system specified by the default parameter in the Boot.ini file. To change the default entry, you must edit the Boot.ini file.

BootP (Bootstrap Protocol)

BootP is used to discover the IP address of a device with a known MAC address. BootP is an enhancement to RARP, and is more commonly implemented than RARP. As its name implies, BootP is used by computers as they boot to receive an IP address from a BootP server. The BootP address request packet sent by the host is answered by the server.

Bootstrap Protocol (BootP)

Bootstrap Router (BSR)

A Bootstrap Router (BSR) is a capability that was added in PIM version 2 to automate and simplify the Auto-RP process. It is enabled by default in Cisco IOS releases supporting PIMv2.

Border Gateway Protocol (BGP)

Border Gateway Protocol (BGP) is a policy-based, interautonomous system routing protocol that exchanges reachability information with other BGP systems.

Bottleneck

A bottleneck is a point in a system of processes that does not have the capacity to perform the functions required of it. This lack of processing capacity impedes overall information flow and negatively impacts the performance of the whole system. Changes in the system, including increased volume, can cause bottlenecks.

Bounce

The longest acceptable round-trip time for a test message to travel between the monitor's home server and the target server.

Boundary layer

Parts of the network architecture that provide a common programming interface. Programmers can use these components to create independently-coded drivers and other programs which extend the operating system's abilities. Boundary layers in Windows include the Transport Driver Interface (TDI) and the Network Device Interface Specification (NDIS) 4.0.

Bridge

A data forwarding device that provides data transfer at the data link layer in the OSI model. A bridge is not used as much in networks because routers have assumed the responsibility for routing data at the network layer of the OSI model.

Bridgehead server

A domain controller that participates in intersite replication.

Broadband

Broadband signaling divides the network medium (cabling) into multiple channels, allowing several signals to traverse the medium at the same time.

Broadcast

In broadcast transmission, a single device transits a message to all of the other devices in a given address range. Broadcast messages can be received by all hosts on the subnet, all subnets, or all hosts on all subnets.

Broadcast domain

The portion of the network that can receive a broadcast. Not all routers have the capability to forward broadcasts. Those that do usually disable this feature and keep the broadcast on the local network.

Broadcast storm

A broadcast storm occurs when so many messages are broadcast across the network at the same time that they exceed the network's bandwidth.

Broadcasts

A request from the source host for a name query request on the local network. Each computer on the local network receives the broadcast and checks its local NetBIOS table to see if it owns the requested name.

Brouter

A device that combines the features of a bridge and a router. For data packets that use a non-routable network/transport protocol, a brouter acts like a bridge. For data packets that use a routable network/transport protocol, a brouter acts like a router.

Browser

A software application you use to display pages from the World Wide Web.

BSR (Bootstrap Router)

A Bootstrap Router (BSR) is a capability that was added in PIM version 2 to automate and simplify the Auto-RP process. It is enabled by default in Cisco IOS releases supporting PIMv2.

Built-in account

A built-in account is an account already created by Windows. The Guest account and the Administrator account are built-in accounts.

Built-in capabilities

Built-in groups are predefined groups that have predetermined set of user rights.

Bus

Bus is a network topology that consists of a trunk cable with nodes either inserted directly into the trunk, or nodes tapping into the trunk using offshoot cables called drop cables.

Byte

A unit of information made up of eight bits. Usually, a byte represents a character.