Bull Escala EPC1200, Connecting Manual, Page: 127 / 224

10-17
Disk Subsystems Cabling Requirements
Optic Fibre Extender
Usage Cases
CAUTION:
The solutions suggested here are not offered in standard.
With the introduction of Optic Fibre Extender, an SSA loop can be extended enabling to
construct an architecture for disaster recovery where the Powercluster configuration is
spread over two buildings within a campus. The maximum length of a fibre link between two
optic fibre extenders is 600 meters. It is assumed that there is a customer’s public network,
and also a customer’s private network for implementing a HA solution in mode 3, which link
all the nodes. The public network and the private network must be separate subnets, and at
least one of them must provide an ethernet LAN segment in order to connect the
Powerconsole or Cluster Console and associated equipments.
The Escala Powercluster offer only contains the optic fibre extender. The cabling (in double
optic fibre) between separate buildings or inside a building is out of scope of the Escala
EPC product and must be performed by ad–hoc professional services. It applies also for
the RS232 lines used between the nodes for exchanging ”keep–alive” messages and the
RS232 line used between two possible Console Concentrators. Since some nodes can be
600m far from other nodes, it is necessary to provide a means to extend an RS232 line to
such a length capability. For this, it is suggested to use a pair of micro modems for each
RS232 link to be extended.
The micro modem referenced ME 762A–F is an example of what can be purchased to
extend RS232 lines. Refer to
EPC Series Site Preparation Guide for more information.
CAUTION:
Both 25M (male) and 25 F (female) micro-modems are available.
– a 25F micro-modem fits the Hub
– a 25M micro-modem fits the console concentrator (CS/2600) .