Marconi OMS 1200
Technical Product Description
221 02-ZAP 701 25/1 Rev C 2006-08-04
© Ericsson AB 2006
03PHB00004AAV-CUA
Commercial in confidence
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(136)
•
In this system failure/removal of Core Card A will most likely mean that the
integrated CCU controller function becomes unavailable. This autonomous
core card master status takeover scheme is the only means by which core
card/core tributary master/slave switchover can be autonomously invoked by
Core B.
•
There will be cases where Core Card A is current slave (or even cases
where ‘A’ is current master, Core A traffic functions have failed, but the CCU
controller has not). Accordingly, a core card may initiate autonomous master
status takeover and then receive master/slave switching instructions from
the CCU controller. If this occurs then the core card Controller actions one of
the following:
−
On detecting failure of the partner core card, set a timer before
autonomously initiating master status takeover. This allows the CCU
controller to issue instructions if it can.
−
After initiating master status takeover, it repeats the process if the CCU
controller subsequently issues the equivalent instructions (assuming this
repeat is not hardware or traffic affecting).
−
After initiating master status takeover, it ignores the CCU controller if it
subsequently issues the equivalent instructions. It does however make
sure that controller instructions resulting from operator Forced Switch
commands are not ignored.
7.7.5 Operator
Entered
Commands
You may make the following requests:
CAUTION!
You should only use Forced Switch (A or B) commands during maintenance
activities when there is a need to remove core cards/core tributary cards from
an in-service system. Otherwise, protection switching must be allowed to
operate autonomously.
Forced Switch effectively locks-out all protection capability and over-rides all
autonomous switching opportunities. The Force is always actioned, even if it
means switching to a failed or missing core card. If a Forced Master core card
subsequently fails, no protection switching actions are invoked
You must clear Forced Switch commands when the system is restored with two
viable core cards/core tributaries
1
Forced Switch to A.
Traffic is selected from Core Unit A, and the in-traffic indicator on Core Unit B
is extinguished.
2
Forced Switch to B.
Traffic is selected from Core-Unit B, and the in-traffic indicator on Core-Unit A
is extinguished.