IBM TotalStorage SAN140M, Installation And Service Manual

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363 Glossary
megabit A unit of measure for data storage, equal to 1,048,576 bits. A megabit
is generally approximated as one million bits.
megabyte A unit of measure for data storage, equal to 1,048,576 bytes. A
megabyte is generally approximated as one million bytes.
message path
controller card
A printed circuit board (ED-5000 Director only) that provides the
mechanism for messages to be sent and received between director
ports. The board also provides a system clock source and central
control and distribution of clocks for MPC, G_Port module (GPM),
and central memory module (CMM) boards.
metropolitan area
network
A high-speed communication network designed to link together sites
in a metropolitan or campus area, comprised of distances up to 100
kilometers. Contrast with
local area network , storage area network , and
wide area network .
MIB See management information base .
MPC card See message path controller card .
multimode optical
fiber
A graded-index or step-index optical fiber that allows more than one
mode (light path) to propagate. Contrast with
singlemode optical fiber .
N
name server In Fibre Channel protocol, a server that allows N_Ports to register
information. This allows devices to obtain information about other
fabric-attached devices by sending queries to the name server.
nickname An alternate name assigned with a WWN to a director, switch, or
other device in a switched fabric.
NL_Port See node loop port .
node In Fibre Channel protocol, a device (server, storage device, or other
peripheral) that is connected to a switched fabric.
node loop port
In Fibre Channel protocol, a connectivity port on an FC-AL device.
An NL_Port communicates with a switched fabric through a director
or switch fabric loop port (FL_Port). See also
fabric loop port .