Glossary

B

b

See bit.

B

See byte.

backbone

Cable on which two or more stations or networks may be attached, typically used to link computer networks at one site with those at another. Smaller branch networks are sometimes called ribs.

backplane

The backplane provides direct current (DC) power distribution and connections for all logic cards.

backup field-replaceable unit

Backup FRU. When an active FRU fails, an identical backup FRU takes over operation automatically (failover) to maintain director or switch and Fibre Channel link operation. See also active field-replaceable unit.

backup FRU

See backup field-replaceable unit.

bandwidth

(1)The amount of data that can be sent over a given circuit. (2) A measure of how fast a network can move information, usually measured in Hertz (Hz).

baud

The unit of signaling speed, expressed as the maximum number of times per second the signal can change the state of the transmission line or other medium. The units of baud are seconds to the negative 1 power. Note: With Fibre Channel scheme, a signal event represents a single transmission bit.

BB_Credit

See buffer-to-buffer credit.

beaconing

Use of light-emitting diodes (LEDs) on ports, port cards, field-replaceable units (FRUs), and switches to aid in the fault-isolation process. When enabled, active beaconing will cause LEDs to flash in order for the user to locate field-replaceable units (FRU’s), switches, or directors in cabinets or computer rooms.

ber

See bit error rate.