Somerdata AROW Series, Additional Instructions For Installation And Operation

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AROW Series
Data Diode
Installation and Operation 7-5
High side
As soon as a module failure condition is detected, the backup module will
take over, send ARP messages to resolve IP/MAC bindings and continue
to send data from the point at which the last acknowledge message was
received.
Depending on when the failure occurs, a corruption may appear in the
data.
Because the failure condition is detected very quickly, very little buffer
will be used while the switchover happens. There should be no need to
throttle back low side data rate.
The failed module should be replaced as soon as possible. Set up a
replacement with the same control IP address as the failed module and
insert it in the place of the failed module.
Optical connection will have to be reset (from the low side) before this
module can become a fully functional backup module.
Low side
The backup module takes over as soon as it detects the failure by
sending out an ARP request and periodic keep alive messages that will
force the sending socket to acknowledge and resend lost data.
Once the lost data is resent, normal operation resumes.
To the end applications, the switch over appears to be a minor network
delay.
Depending on when the failure occurs, a corruption may appear in the
data at the high side.
The failed module should be replaced as soon as possible. Set up a
replacement with the same control IP address as the failed module and
insert it in the place of the failed module.
Optical connection will be reset automatically and the module receives its
setting from the live module, so that the new module takes on the role of
backup module as soon as possible.
Loss of Optical link
If both Live and backup optical links of the high side live module fail, it
will notify the backup module, which will take over as soon as possible in
the same manner as a module failure.
Data corruption can occur if data is being transferred as the optical links
are failing.