FW V06.XX/HAFM SW V08.02.00 HP StorageWorks SAN High Availability Planning Guide (AA-RS2DD-TE, July 2004)

Planning Considerations for Fibre Channel Topologies
64 SAN High Availability Planning Guide
Figure 21: Shared mode operation
■ Switched mode — When set to switched mode or by default, the switch
bypasses full loop arbitration and enables frame transmission through logical
connected device pairs. Connections can be established between H_Port pairs,
or between an H_Port and fabric loop port (FL_Port). Switched mode also
allows independent operation of looplets of devices, each connected through
an unmanaged hub, and each attached to a single switch H_Port. Because of
opportunistic bandwidth sharing, all looplets or connected device pairs
operate half duplex or full duplex at 1.0625 Gbps.
Switched mode operation is illustrated in Figure 22. Part (A) shows four
device transmission pairs using all eight H_Ports (server S
1
to device D
1
,
server S
2
to device D
2
, server S
3
to device D
3
, and server S
4
to device D
4
).
All four transmissions operate independently at 1.0625 Gbps. Subsequently,
part (B) shows two device transmission pairs using four H_Ports (server S
2
to
device D
2
and server S
3
to device D
3
), and public device D
1
connected to
fabric-attached server S
5
. All four transmissions operate at 1.0625 Gbps.