B

backbone area

In OSPF, an area that consists of all networks in area ID 0.0.0.0, their attached routers, and all area border routers.

backbone router

An OSPF router with all operational interfaces within area 0.0.0.0.

backplane

On an M40 router, component of the Packet Forwarding Engine that distributes power, provides signal connectivity, manages shared memory on FPCs, and passes outgoing data cells to FPCs. See also flexible PIC concentrator (FPC).

backup

Denotes a Routing Engine in a dual Routing Engine chassis that is not currently controlling the router’s operations.

backup designated router

An OSPF router on a broadcast segment that monitors the operation of the designated router and takes over its functions in the event of a failure.

bandwidth

The range of transmission frequencies a network can use, expressed as the difference between the highest and lowest frequencies of a transmission channel. In computer networks, greater bandwidth indicates faster data-transfer rate capacity.

base station controller (BSC)

Key network node in 3G systems that supervises the functioning and control of multiple base transceiver stations.

base station subsystem (BSS)

Composed of the base transceiver station (BTS) and base station controller (BSC).

Base Station System GPRS Protocol (BSSGP)

Processes routing and quality-of-service (QoS) information for the BSS.

base transceiver station (BTS)

Mobile telephony equipment housed in cabinets and co-located with antennas. Also known as a radio base station.

Bellcore

Bell Communications Research. Research and development organization created after the divestiture of the Bell System. It is supported by the regional Bell holding companies (RBHCs), which own the regional Bell operating companies (RBOCs).

Bellman-Ford algorithm

Algorithm used in distance-vector routing protocols to determine the best path to all routes in the network.

bit error rate test (BERT)

A test that can be run on an electrical point-to-point interface (T1, E1, T3, E3, etc.) to determine whether it is operating properly.

bit field match conditions

The use of fields in the header of an IP packet as match criteria in a firewall filter.

bootstrap router

The single router in a multicast network responsible for distributing candidate rendezvous point information to all PIM-enabled routers.

Border Gateway Protocol (BGP)

Exterior Gateway Protocol used to exchange routing information among routers in different Autonomous Systems.

broadcast

Operation of sending network traffic from one network node to all other network nodes.

Building Integrated Timing Source (BITS)

Dedicated timing source that synchronizes all equipment in a particular building.

bundle

Collection of software that makes up a JUNOS software release.