System information

Glossary
g-37
Glossary
loop A loop is a configuration of devices connected to the fabric via a
fabric loop port (FL_Port) interface card.
loop address In Fibre Channel protocol, a term indicating the unique ID of a node
in Fibre Channel loop topology, sometimes referred to as a loop ID.
loopback plug In a fiber optic environment, a type of duplex connector used to wrap
the optical output signal of a device directly to the optical input.
Contrast with
protective plug. Synonymous with wrap plug.
loopback test Test that checks attachment or control unit circuitry, without
checking the mechanism itself, by returning the output of the
mechanism as input.
loop initialization
primitive
LIP. In an arbitrated loop device, a process by which devices
connected to hub ports (H_Ports) on the arbitrated loop device notify
other devices and the switch of the presence in the loop by sending
LIP sequences and subsequent frames through the loop. This process
allows linked arbitrated loop devices to perform fabric loop port
(FL_Port) arbitration as they link through hub ports.
loop master In an arbitrated loop device, a reference to the loop master
world-wide name (WWN) field in the Loop View, the loop master is
the arbitrated loop device that is responsible for allocating arbitrated
loop physical addresses (AL-PAs) on the loop. An arbitrated loop
device becomes the loop master through arbitration when there are
multiple arbitrated loop devices on the loop. The arbitrated loop
device with the lowest WWN becomes the loop master.
loop port L_Port. Synonym for hub port.
loop switches Loop switches support node loop port (NL_Port) Fibre Channel
protocols. Switches sold as loop support but upgradeable to fabric
switches recounted as loop switches.
LPAR See logical partition.
L_Port Loop port. Synonym for hub port.
LUN See logical unit number.