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Glossary

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auxiliary port

The console port on the back of Cisco routers that allows

you to dial the router and make console configuration settings.

B8ZS

Binary 8-Zero Substitution: A line-code type, interpreted at the remote

end of the connection, that uses a special code substitution whenever eight
consecutive zeros are transmitted over the link on T-1 and E-1 circuits. This
technique assures ones density independent of the data stream. Also known as
bipolar 8-zero substitution. Contrast with: AMI. See also: ones density.

backbone

The basic portion of the network that provides the primary

path for traffic sent to and initiated from other networks.

back end

A node or software program supplying services to a front end.

See also: server.

bandwidth

The gap between the highest and lowest frequencies employed

by network signals. More commonly, it refers to the rated throughput
capacity of a network protocol or medium.

bandwidth on demand (BoD)

This function allows an additional B

channel to be used to increase the amount of bandwidth available for a
particular connection.

baseband

A feature of a network technology that uses only one carrier fre-

quency. Ethernet is an example. Also named "narrowband." Compare with:
broadband.

baseline

Baseline information includes historical data about the network

and routine utilization information. This information can be used to deter-
mine whether there were recent changes made to the network that may
contribute to the problem at hand.

Basic Management Setup

Used with Cisco routers when in setup mode.

Only provides enough management and configuration to get the router
working so someone can telnet into the router and configure it.

baud

Synonymous with bits per second (bps), if each signal element repre-

sents one bit. It is a unit of signaling speed equivalent to the number of
separate signal elements transmitted per second.

B channel

Bearer channel: A full-duplex, 64Kbps channel in ISDN that

transmits user data. Compare with: D channel, E channel, and H channel.

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