IBM 3534-F08 Installation And User Manual page 88

the node into the loop. A node that fails or is powered
off is automatically removed from the loop.
ID. See identifier.
identifier (ID). A sequence of bits or characters that
identifies a user, program, device, or system to another
user, program, device, or system.
IDLE. Continuous transmission of an ordered set over
a Fibre-channel link when no data is being transmitted
for the purpose of keeping the link active and
maintaining bit, byte, and word synchronization.
IETF. Internet Engineering Task Force.
information unit (IU). A set of information as defined
by either upper-level process protocol definition or
upper-lever protocol mapping.
initiator. The system component that originates an
input/output (I/O) command over an I/O bus or network.
I/O adapters, network interface cards, and intelligent
controller device I/O bus control application-specific
integrated circuits (ASICs) are typical initiators. See also
target.
in-order delivery (IOD). A parameter that, when set,
guarantees that frames are either delivered in order or
dropped.
integrated fabric. The fabric created by six switches
that are cabled together and are configured to handle
traffic as a seamless group.
Internet Protocol (IP). A protocol that routes data
through a network or interconnected networks. Internet
Protocol (IP) acts as an intermediary between the
higher protocol layers and the physical network.
inter-switch link (ISL). A Fibre link between two
switches.
IOD. See in-order delivery.
IP. See internet protocol.
ISL. See inter-switch link.
ISL Trunking. A feature that enables distribution of
traffic over the combined bandwidth of up to four
inter-switch links (ISLs) between adjacent switches,
while preserving in-order delivery. A set of trunked ISLs
is called a trunking group; each port employed in a
trunking group is called a trunking port. See also master
port.
isolated E_port. An E_port that is online but not
operational between switches due to overlapping
domain ID or nonidentical parameters such as
E_D_TOVs. See also expansion port.
IU. See information unit.
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IBM TotalStorage SAN Switch: 3534 Model F08 Installation and User's Guide
K28.5. A special 10-bit character used to indicate the
beginning of a transmission word that performs Fibre
channel control and signaling functions. The first seven
bits of the character are the comma pattern. See also
comma.
LAN. See local area network.
latency. The time from the initiation of an operation
until something actually starts happening (for example,
data transmission begins).
LED. See light-emitting diode.
light-emitting diode (LED). A semiconductor chip that
gives off visible or infrared light when activated.
link. In Fibre Channel technology, two unidirectional
fibers carrying data in opposite directions, along with
their associated transmitters and receivers. See also
circuit.
link services. A protocol for link-related actions.
LIP. See loop initialization primitive.
LM_TOV. See loop master timeout value.
local area network (LAN). A computer network
located on a user's premises within a limited
geographical area.
logical unit number (LUN). An identifier used on a
small computer systems interface (SCSI) bus to
distinguish among up to eight 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. LWL can also refer to the type
of gigabit interface converter (GBIC) or small form-factor
pluggable (SFP). See also short wavelength.
loop. A configuration of devices connected to the
fabric by way of a fabric loop port (FL_port) interface
card.
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 hex 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. Loop
initialization can be used to assign arbitrated loop
physical addresses (AL_PAs), detect loop failure, or
reset a node.
loop initialization primitive (LIP). The signal used to
begin initialization in a loop, which indicates either loop
failure or resetting of a node.