CCNA Cisco Certified Network Associate Study Guide - FTP Server

658 Glossary
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 T1 and E1 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.
baseband A feature of a network technology that uses only one carrier frequency,
for example Ethernet. Also named “narrowband.” Compare with:
broadband.
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 represents
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.
beacon An FDDI device or Token Ring frame that points to a serious
problem with the ring, such as a broken cable. The beacon frame carries the
address of the station thought to be down. See also: failure domain.
BECN Backward Explicit Congestion Notification: BECN is the bit set by a
Frame Relay network in frames moving away from frames headed into a congested
path. A DTE that receives frames with the BECN may ask higher-level
protocols to take necessary flow control measures. Compare with: FECN.