HP XP Continuous Access Software - Manual (Page 35)

Continuous Access XP user guide for the XP1024/XP128 35
• Switch connection: Up to three optical fibre cables (per hard zone) are connected via switches to
connect the devices. Up to two switches can be used.
Figure 7 Switch connection
• Extender connection: Protocol converters and switches are used to connect devices across large
distances.
Figure 8 Extender connection
Serial remote copy connections
Figure 9 shows Continuous Access XP serial remote copy connection configurations. The MCU and RCU
of each pair must be connected via multimode ESCON cables. For distances greater than 3 km,
single-mode cables up to 20 km in length and ESCDs and/or ESCON repeaters are required. ESCDs
support the extended distance facility (XDF), which uses single-mode ESCON cables up to 20 km.
ESCON repeaters support single-mode-to-single-mode connections or single-mode-to-multimode
connections. When disk arrays running Continuous Access XP are more than 9 km apart, XDF
connections provided by ESCDs or ESCON repeaters are required. Continuous Access XP operations can
be performed at distances of up to 43 km (26.7 miles) using standard ESCON support. Long-distance
solutions are provided using approved channel extenders and communication lines.
Figure 9 Serial remote copy connections