ATTO Technology FC-21PS, FC-42XS, FC-41XS Fibre Channel is a key technology for storage, Glossary

Term

Definition

ANSI

American National Standards Institute

arbitrate

process of selecting one L_Port from a collection of ports which ask for use of the arbitrated loop

at the same time

arbitrated loop

a loop topology (FC-AL) in which two or more ports are interconnected, but only two ports can

communicate at one time; low-cost solution which may or may not use hubs and switches

auto negotiation

hardware senses and automatically responds depending on configuration

BER

Bit Error Rate: a measure of transmission accuracy; the ratio of bits received in error to bits sent

bit

smallest unit of data a computer can process: a single binary digit with a value of either 0 or 1

bus

a collection of unbroken signal lines used to transmit information from one part of a computer

system to another; taps on the lines connect devices to the bus

byte

an ordered set of 8 bits

channel

a point-to-point link which transports data from one point to another

CPU

Central Processing Unit: the portion of the computer that actually performs computations

CRC

Cyclic Redundancy Check: an error-correcting code which calculates a numeric value for received

and transmitted data; if no error has occurred during transmission, the CRC for both received and

transmitted data should be the same

destination

a value in the frame header of each frame which identifies the port in the node where the frame is

address

being sent

device driver

a program that allows a microprocessor to direct the operation of a peripheral device

DMA

Direct Memory Access: a way to move data from a storage device directly to RAM without using

the CPU’s resources

DMA bus master

allows a peripheral to control the flow of data to and from system memory by block as opposed to

allowing the processor to control the data by bytes (PIO or programmed I/O)