Comtech EF Data CLO-10 - Manual (Page 87)

CLO-10 Link Optimizer Revision 1
Redundant System Operation MN/CLO-10.IOM
A.1.2 Redundancy System Operational Rules
For proper operation of the CLO-10 Daisy Chain Redundancy System, the operational rules
outlined in this section should be understood by the user.
General Rules:
Rule 1: Which Traffic Unit is Active? All Traffic Units are considered to be set as Active in the
examples cited in these rules. Any Traffic Unit that is not Active is not considered part of the
redundant system; it will not be polled for configuration or faults by the Redundant Unit.
Rule 2: What to Bridge? The Redundant Unit will bridge the first Traffic Unit set to Active.
Rule 3: The Redundant Unit is not under the user’s control. Any configuration change made
by the user will be overwritten on the Redundant Unit. The same is true of a Traffic Unit that is
being backed up by the Redundant Unit.
Rule 4: Which Traffic Unit has Priority? Traffic Unit #1 has the highest priority. Traffic Unit
#12 has the lowest priority.
Rule 5: Power Recovery. If the Redundant Unit loses power, the last known “Redundancy
State” will return.
For example: If Traffic Unit #2 was being backed up before power is lost, it will remain backed
up when power is restored.
For Manual Switch mode:
Rule 6: Just do it. The Redundant Unit will bridge or back up any Traffic Unit selected,
regardless of faults of the Traffic Unit or Redundant Unit.
For Automatic Switch mode:
Rule 7: Redundant Unit will back up highest priority failed Traffic Unit. Any Traffic Unit that
faults will first be bridged, then – if the Redundant Unit stays fault-free – backed up. If a Traffic
Unit loses power, the Redundant Unit will treat the incident as a Traffic Unit fault. If a fault occurs
simultaneously in two or more Traffic Units, the Redundant Unit will bridge, then back up the
Traffic Unit with the highest priority – that is, the lowest-numbered Traffic Unit will be selected
over all other Traffic Units in the redundancy system.
Rule 8: Faulted Unit is backed up. Once a Traffic Unit is Backed-up (offline) and no other
Traffic Units show faults, the Redundant Unit will stay online unless this same Traffic Unit is
now fault-free and the Redundant Unit later has faults.
Additionally, if the Redundant Unit and Traffic Unit remains fault-free and a different Traffic
Unit faults, the “restore” function will begin – the original Traffic Unit will go back online and
the Redundant Unit will bridge and back up this newly failed Traffic Unit. The other option is to
have the user take the Redundant Unit offline manually.
A–3