IBM TotalStorage SAN140M, Installation And Service Manual

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361 Glossary
L
LAN See local area network .
laser Acronym for light amplification by stimulated emission of radiation. A
device that produces a powerful, narrow beam of coherent light of a
single wavelength by simulating the emissions of photons from
atoms, molecules, or ions.
latency For Fibre Channel applications, the time elapsed between receipt of a
data frame at a switch’s incoming F_Port to retransmission of the data
through the switch’s outgoing F_Port to a destination N_Port.
LED
See light-emitting diode .
light-emitting diode
A semiconductor chip that emits visible or infrared light when
electricity passes through it. LEDs are used on director or switch front
bezels and FRUs to provide visual status indications.
LIN See link incident .
link incident The interruption of traffic on a Fibre Channel link due to loss of light
or other malfunction.
Link Incident Log
A log recorded at the Element Manager application that displays a
history of Fibre Channel link incidents (with associated port
numbers) for a director or switch.
LIP sequence See loop initialization primitive sequence .
local area network A communication system that links computers in a network through
a wiring-based cable scheme. LANs connect servers, storage devices,
and printers together to allow users to communicate and share
resources. LAN devices are linked in a localized geographical area
(for example, a building or campus), and are typically user-owned
and do not run over leased lines. Contrast with
metropolitan area
network , storage area network , and wide area network .
logical port address The address used to specify port connectivity parameters when a
director or switch is set to operate in S/390 mode.
logical unit number In systems network architecture, a LUN is a number assigned to each
logical partition of a storage device. Each logical partition is uniquely