McDATA Eclipse 2640 SAN, Administration And Configuration Manual

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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