9500 MXC User Manual
3DB 23063 ADAA - Rev 004 July 2007 Vol. V-1-11
• For most tests Available/Unavailable time should not change, and the Severely
Errored Second count will mirror the Errored Second count.
Before You Begin
• Ensure the link is operating alarm-free, and that path conditions are normal.
• For hot-standby and diversity use the System/Controls screen to check that both
have default primary and secondary RAC settings. If necessary, reset and
ensure Auto / Lock Off is selected.
• For a ring test ensure the node has been switched on for not less than 5 minutes
to ensure completion of internal system checks.
Hot-standby and Space Diversity
Tx switching is not hitless. Rx path switching is hitless, providing the assigned
online Rx RAC is not withdrawn from its backplane.
Test procedures are provided for:
• Local alarm Tx switch: local Tx switch forced by local Tx alarm.
• Silent alarm Tx switch: local Tx switch forced from remote end by LOS (loss
of signal).
• Rx switch.
Local-alarm Tx Switching Procedure
The procedure requires withdrawal, in turn, of RAC cards.
Test procedure:
1. Set a BER test on a DAC trib with a remote loopback. Confirm error-free
operation.
2. Withdraw the online Tx RAC (default primary) from its backplane to initiate
a Tx switch to the standby Tx (default secondary RAC).
3. Confirm that service is restored within a count of one errored second (possibly
two). Refer to Test Measurement on page 1-7.
When a card is unplugged the NCC status LED will flash orange and a
major alarm and a card missing icon will appear in the status bar of all CT
screens (bottom of screen).
4. Re-install the primary RAC and confirm that no switch occurs; Tx online
Before testing ring protection a node must have been switched on for not less
than 5 minutes to ensure completion of internal system checks and updates.
Regardless, no protection switch operation is permitted by the Node within a one
to two minute period from power-on, which is also the time typically required
before CT log-in is permitted.
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