IBM SAN16B-2 - TotalStorage Express Model Switch, User And Service Manual

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local area network (LAN). A network that connects
several devices into a limited area (such as a single
building or campus) and that can be connected to a
larger network.
logical unit number (LUN). An identifier used on a
SCSI bus to distinguish among devices (logical units)
with the same SCSI ID.
long wavelength (LWL). A type of fiber optic cabling
that is based on 1300 mm lasers and supports link
speeds of 1.0625 Gbps. Can also refer to the type of
GBIC or SFP. See also short wavelength .
loop. A configuration of devices that are connected to
the fabric by way of a fabric loop port (FL_port)
interface card.
loop circuit. A temporary bidirectional communication
path established between loop ports (L_ports).
loop failure. Loss of signal within a loop for any
period of time, or loss of synchronization for longer than
the timeout value.
loop_ID. A hexadecimal value representing one of the
127 possible arbitrated loop physical address (AL_PA)
values in an arbitrated loop.
loop initialization. The logical procedure used by a
loop port (L_port) to discover its environment. Can be
used to assign arbitrated loop physical address (AL_PA)
addresses, detect loop failure, or reset a node.
loop initialization primitive (LIP). The signal used to
begin initialization in a loop. Indicates either loop failure
or resetting of a node.
looplet. A set of devices connected in a loop to a port
that is a member of another loop.
loop master timeout value (LM_TOV). The minimum
time that the loop master waits for a loop initialization
sequence to return.
loop mode. One of the modes for a loop port (L_port).
An L_port is in loop mode when it is in an arbitrated
loop and is using loop protocol. An L_port in loop mode
can also be in participating mode or nonparticipating
mode. See also loop port , fabric mode , participating
mode , and nonparticipating mode .
loop port (L_port). A node port (NL_port) or fabric
port (FL_port) that has arbitrated loop capabilities. An
L_port can be either in fabric mode or loop mode. See
also fabric mode , loop mode, nonparticipating mode,
and participating mode.
loop port state machine (LPSM). The logical entity
that performs arbitrated loop protocols and defines the
behavior of loop ports (L_ports) when they require
access to an arbitrated loop.
L_port. See loop port .
LPSM. See loop port state machine .
LSAN. Logical storage area network. An LSAN
enables device and storage connectivity that spans two
or more fabrics.
LSR. Link state record.
LSU. Link state update.
LUN. See logical unit number .
LWL. See long wavelength .
M
management information base (MIB). A simple
network management protocol (SNMP) structure to help
with device management, providing configuration and
device information.
master port. As relates to trunking, the port that
determines the routing paths for all traffic flowing
through the trunking group. One of the ports in the first
inter-switch link (ISL) in the trunking group is designated
as the master port for that group. See also ISL
Trunking .
MIB. See management information base .
multicast. The transmission of data from a single
source to multiple specified node ports (N_ports), as
opposed to all the ports on the network. See also
broadcast and unicast .
multimode. A fiber optic cabling specification that
allows up to 500 m (1640.5 ft) between devices.
N
name server. Frequently used to indicate Simple
Name Server. See also simple name server .
NEMA. National Electrical Manufacturers Association.
network time protocol (NTP). An Internet standard
protocol that provides synchronization of computer clock
times in a network with times provided by radio or
atomic clocks on the Internet.
NL_port. See node loop port .
node. A Fibre Channel device that contains a node
port (N_port) or node loop port (NL_port).
node loop port (NL_port). A node port that has
arbitrated-loop capabilities. Used to connect an
equipment port to the fabric in a loop configuration
through an FL_Port.
node name. The unique identifier for a node,
communicated during login and port discovery.
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SAN16B-2 Installation, Service, and User’s Guide