To represent all iSCSI initiators and sessions, each iSCSI portal has one iSCSI virtual initiator (VI) to the FC
fabric that appears as an N_Port device with a special WWN format. Regardless of the number of iSCSI
initiators or iSCSI sessions sharing the portal, Fabric OS uses one iSCSI VI per iSCSI portal.
Figure 19
shows the interaction of different layers from the iSCSI initiator stack to the FC target stack,
including the iSCSI gateway service used during protocol translation.
Application
T C P /IP
iS C S I initiator
Figure 19
iSCSI-to-FC translation
Basic versus advanced LUN mapping
Fabric OS provides the following two methods to map physical FC targets (LUNs) to iSCSI virtual targets
(VTs):
• "Basic LUN
• "Advanced LUN
Basic LUN mapping
Fabric OS provides a mechanism that maps LUNs to iSCSI VTs, a one-to-one mapping with unique iSCSI
Qualified Names (IQNs) for each target. It presents an iSCSI VT for each native FC target to the IP network
and an iSCSI VI for each iSCSI port to the FC fabric.
Figure 20
shows a basic LUN mapping scenario for an FC target with four LUNs.
iS C S I virtual target (V T )
LUN
0
1
2
3
Figure 20
iSCSI VT basic LUN mapping
254 iSCSI Gateway services
S C S I
iS C S I
iS C S I
T C P /IP
iS C S I virtual
target (V T )
mapping" on page 254
mapping" on page 255
F C P (F C -4)
F C (F C -2/F C -3)
iS C S I virtual
initiator (V I)
iS C S I gateway s ervic e
F C target
LUN
0
1
2
3
40. 9
S torage
(device s erver)
S C S I
F C P
F C
F C target
40. 3