User`s guide

Glossary 375
data between CPUs and from a CPU to disk
arrays and other peripherals.
HMMP HyperMedia Management Protocol
HMMS HyperMedia Management Schema - the
definition of an implementation-independent,
extensible, common data description/schema
allowing data from a variety of sources to be
described and accessed in real time regardless of
thesourceofthedata.Seealso:WEBM,HMMP
HSM Hierarchical Storage Management - A
software and hardware system that moves files
from disk to slower, less expensive storage media
based on rules and observation of file activity.
Modern HSM systems move files from magnetic
disk to optical disk to magnetic tape.
HUB A Fibre Channel device that connects nodes
into a logical loop by using a physical star
topology. Hubs will automatically recognize an
active node and insert the node into the loop. A
node that fails or is powered off is automatically
removed from the loop.
HUB Topology see Loop Topology
Hunt Group A set of associated Node Ports
(N_Ports) attached to a single node, assigned a
special identifier that allows any frames
containing this identifier to be routed to any
available Node Port (N_Port) in the set.
In-Band Signaling This is signaling that is
carried in the same channel as the information.
Also referred to as inband.
Information Unit A unit of information defined by
an FC-4 mapping. Information Units are
transferred as a Fibre Channel Sequence.
Intermix A mode of service defined by Fibre
Channel that reserves the full Fibre Channel
bandwidth for a dedicated Class 1 connection,
but also allows connection-less Class 2 traffic to
share the link if the bandwidth is available.
I/O Input/output
IP Internet Protocol
IPI Intelligent Peripheral Interface
Isochronous Transmission Data transmission
which supports network-wide timing
requirements. A typical application for
isochronous transmission is a broadcast
environment which needs information to be
delivered at a predictable time.
JBOD Just a bunch of disks.
Jukebox A device that holds multiple optical
disks and one or more disk drives, and can swap
disks in and out of the drive as needed.
L_Port Loop Port - A node or fabric port capable
of performing Arbitrated Loop functions and
protocols. NL_Ports and FL_Ports are
loop-capable ports.
LAN See Local Area Network - A network
covering a relatively small geographic area
(usually not larger than a floor or small building).
Transmissions within a Local Area Network are
mostly digital, carrying data among stations at
rates usually above one megabit/s.
Latency A measurement of the time it takes to
send a frame between two locations.
LC Lucent Connector. A registered Trademark of
Lucent Technologies.
Link A connection between two Fibre Channel
ports consisting of a transmit fibre and a receive
fibre.
Link_Control_Facility A termination card that
handles the logical and physical control of the
Fibre Channel link for each mode of use.
LIP A Loop Initialization Primitive sequence is a
special fibre channel sequence that is used to
start loop initialization. Allows ports to establish
their port addresses.
Local Area Network (LAN) A network covering a
relatively small geographic area (usually not
larger than a floor or small building).
Transmissions within a Local Area Network are
mostly digital, carrying data among stations at
rates usually above one megabit/s.
Login Server Entity within the Fibre Channel
fabric that receives and responds to login
requests.