HP StorageWorks Fabric OS 6.1.1 administrator guide (5697-0235, December 2009)

428 FICON fabrics
there are only 2 domains in a path from a FICON Channel interface to a FICON Control Unit interface.
Figure 56 Cascaded configuration, two switches
Figure 57 Cascaded configuration, three switches
Channel
A
Control
Unit
B
Switch
Domain ID = 21
Switch
Domain ID = 22
Channel
A
Control
Unit
C
Control
Unit
D
Switch
Domain ID = 23
Switch
Domain ID = 21
Switch
Domain ID = 22