System information

Glossary
g-7
Glossary
British thermal unit Btu. The quantity of heat required to raise the temperature of one
pound of water by one degree Fahrenheit (D).
broadband Large bandwidth communications channel capable of multiple,
parallel high-speed transmissions.
broadcast In Fibre Channel protocol, to send a transmission to all node ports
(N_Ports) on a fabric. See also
broadcast frame.
broadcast frame In Fibre Channel protocol, a frame whose destination address
specifies all node ports (N_Ports) in the fabric. See also
broadcast.
Btu See British thermal unit.
buffer Storage area for data in transit. Buffers compensate for differences in
processing speeds between devices. See
buffer-to-buffer credit.
buffer-to-buffer credit BB_Credit. (1) The maximum number of receive buffers allocated to a
transmitting node port (N_Port) or fabric port (F_Port). Credit
represents the maximum number of outstanding frames that can be
transmitted by that N_Port or F_Port without causing a buffer
overrun condition at the receiver. (2) The maximum number of
frames a port can transmit without receiving a receive ready signal
from the receiving device. BB_Credit can be adjustable to provide
different levels of compensation.
bus The path that carries data between the computer (microprocessor)
and peripheral devices. An IDE interface cable and a small computer
system interface (SCSI) cable are both examples.
bypassed port If a port is bypassed, all serial channel signals route past the port. A
device attached to the port cannot communicate with other devices in
the loop.
byte Abbreviated as B. A byte generally equals eight bits, although a byte
can equal from four to ten bits. A byte can also be called an octet See
also
octet.
C
cache Random access memory (RAM) that is used by the redundant array
of independent disks (RAID) controller to increase I/O throughput. If