6
Glossary
fabric
A Fibre Channel switch or two or more Fibre Channel switches interconnected to physically
transmit data between any two N_Ports on the switch or switches
FC
Fibre Channel
F_port
A port in the Fibre Channel fabric where a N_port may attach
FL_port
A port in the Fibre Channel fabric where a NL_port may attach in an arbitrated loop
frame
an indivisible unit for transfer of information in Fibre Channel
frame header
the first field in the frame containing the address and other control information about the frame
full duplex
a communication protocol which allows transmission in both directions at the same time
half duplex
a communication protocol which allows transmission in both directions, but only one direction at a
time
host
a processor, usually a CPU and memory, which communicates with devices over an interface
initiator device
A component which originates a command
L_port
a port in an arbitrated loop, either a NL_port or a FL_port
LED
Light-emitting diode: a type of diode that emits light when current passes through it; visible LEDs
are used as indicator lights on all sorts of electronic devices
LUN
Logical Unit Number: an identifier for a logical unit (0-7)
multi-mode fiber
an optical fiber which can carry several beams of light at once
N_port
a port attached to a node used with point to point or fabric configurations
NL_ port
a port attached to a node in Fibre Channel arbitrated loop or fabric loop configuration
originator
an initiating device; a component which originates a command
parity checking
A method which verifies the accuracy of data transmitted over the SCSI bus by adding one bit in
the transfer to make the sum of all the bits either odd or even (for odd or even parity); an error
message occurs if the sum is not correct
PCI
Peripheral Component Interconnect. Allows peripherals to be connected directly to computer
memory, bypassing the slower ISA and EISA busses
point-to-point
a topology where two ports communicate
port
an access point in a device: see N_port, NL_port, etc.
port address
also port number; the address, assigned by the PCI bus, through which commands are sent to a
host adapter board
port number
see port address
receiver
the ultimate destination of data transmission; a terminal device
scatter/gather
a device driver feature which allows the host adapter to modify a transfer data pointer so that a
single host adapter can access many segments of memory, minimizing interrupts and transfer
overhead
SCSI
Small Computer Systems Interface: a processor-independent standard for system-level interface
between a computer and intelligent devices including hard disks, floppy disks, CD-ROM, printers,
scanners, etc.
single-mode fiber an optical fiber with a small core which supports one wavelength (ray of light); the core radius is
nearly equal to the wavelength of the source
topology
logical layout of the parts of a computer system or network and their interconnections
transceiver
a transmitter/receiver module
transfer rate
the rate at which bytes or bits are transferred, as in megabytes or gigabits per second
Term
Definition
