FW 05.01.00 and SW 07.01.00 HP StorageWorks SAN High Availability Planning Guide (AA-RS2DC-TE, June 2003)

Planning Considerations for Fibre Channel Topologies
66 SAN High Availability Planning Guide
Figure 26: Private loop connectivity
Planning for Private Arbitrated Loop Connectivity
Private arbitrated loop topology supports the clustering of isolated servers and
storage subsystems into workgroup or departmental SANs. This topology is well
suited to small and mid-sized configurations where modest connectivity levels and
high data transmission speeds are required. The topology also supports low-cost
switching and connectivity in environments where the per-port cost of a director is
prohibitive.
Private arbitrated loop topology:
■ Supports the connection of up to 125 node (device) ports.
■ Reduces connection costs by distributing the routing function through each
loop port (loop functionality is a small addition to normal Fibre Channel port
functionality).
■ Provides a fully blocking architecture that allows a single connection between
any pair of loop ports at any time. Connections between a third loop port and
busy ports are blocked until communication between the first connection pair
ends.
D1
S1
Embedded FL_Port
H_Ports
B_Port
Loop Switch