Chaparral K5312/K7313 - Manual (Page 147)

Glossary
G-3
Initiator mode—Initiator mode is the configuration mode of a device in which an
FC or SCSI initiator requests operations to be performed by an FC or SCSI target
device.
Logical unit number or logical unit (LUN)—A LUN is a subdivision of a SCSI
target. For SCSI-3, each SCSI target supports up to 64 LUNs. An FC host using
LUNs can address multiple peripheral devices that may share a common controller.
Loop address—Loop address is an FC term that indicates the unique ID of a node
in FC loop topology. A loop address is sometimes referred to as a Loop ID.
Low voltage differential (LVD)—LVD is a method of powering SCSI cables that
will be formalized in the SCSI-3 specifications. LVD uses less power than the current
differential drive (HVD), is less expensive, and allows for higher speeds such as those
of Ultra-2 SCSI. LVD requires 3.3 volts (versus 5 volts for HVD).
Management Information Base (MIB)—A MIB is a database of managed
objects accessed by network management protocols. An SNMP MIP is a set of
parameters that an SNMP management station can query or set in the SNMP agent of
a network device (for example, a router).
Mapping table—A mapping table is a table indexed by sequential LUN values. The
values indicate select bus:target:LUN devices. Mapping tables are used by some
routers to perform FC-to-SCSI operations by default.
Point to Point—A point-to-point connection is a communication link between two
end systems. The point-to-point topology is one of three FC topologies, in which two
ports are directly connected by a link; there are no fabric, loop, or switching elements
present.
Router—A router is a device that enables connectivity between SCSI devices and
FC networks. It routes each data command to the appropriate SCSI channel based on
the address it is intended for.
SCSI adapter —A SCSI adapter is a 16-bit fast/wide differential or 8-bit narrow
single-ended physical connection between a router and SCSI devices. Each SCSI
adapter supports up to 16 (fast/wide) or 8 (narrow) SCSI devices, including itself.
SCSI addressing—Each device supported by a SCSI adapter has its own unique
SCSI address, which dictates the device’s priority when arbitrating for access to the
SCSI bus. A SCSI address of 7 has the highest priority. For a fast/wide SCSI adapter
that supports up to 16 devices, the next highest priority address is 6, then 5, 4, 3, 2, 1,
0, 15, 14, 13, 12, 11, 10, 9, and 8. The narrow SCSI adapter supports up to eight
devices, including itself. The SCSI address 7 has the highest priority, followed by 6,
5, 4, 3, 2, 1, and 0.