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
110
(136)
On detection of a core card failure, the Mux Controller instructs all destination
ports to select traffic from the other core unit. The failed core card is then
taken out-of-traffic by the Mux Controller. The card-in-traffic indicator of the
failed unit is extinguished indicating that card may be removed without
degradation of traffic. On replacement of the core card, the system
automatically reverts to protected operation.
2
Removal of a working non-selected core card.
The card-in-traffic indicators are illuminated on both cards, indicating that
removal of either card may cause errors. In this case, you must switch the unit
out-of-traffic via the local terminal by issuing a Forced-Switch to the other
core-unit. Removal of this unit may then be carried out without degradation of
traffic. [Note 2].
3
Removal of selected core card.
The card-in-traffic indicators are illuminated on both cards. Before the card is
removed, the selected traffic must first be manually switched to the other core
unit using the Local Terminal by instructing a Forced-Switch to the other core
unit. [Note 1 and 2].
Note:
1.
Situation
above may cause errors during the switching-over of the
selected switch unit and should be avoided if possible.
Note:
2.
To restore core card protection capability, you must issue a Clear Forced
Switch command on replacement of the switch unit.
If a core card is removed, on being replaced for the purposes of traffic protection, it is
configured according to existing states (i.e. working/protection) as dictated by the
other core. This is to prevent the two core units becoming out of phase.
7.7.3
Protection Switching Criteria
Both of the system's peripheral traffic cards detect the same failure criteria for core
card protection, and the core card's own traffic modules; namely the SDH line
interface modules and the core tributary cards. These line and tributary modules
monitor for failures on both their parent core card and the protection core card.
7.7.3.1 Failure
Detection
Switch protection operates automatically, according to the conditions detected by the
destination ports, or on demand by the Multiplexer Controller.
The conditions, which may initiate switching, are:
•
Mismatch on path identification number
•
Failure of parity checks
•
Failure of alignment (enable/disable)
•
Loss-of system-clock transitions.
