Specifications

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Cisco MGX 8850 (PXM45) and MGX 8950 Software Configuration Guide
Release 3, Part Number 78-14788-01 Rev. C0, January 2004
Chapter 7 Switch Operating Procedures
Managing Redundant APS Lines
Top Back Card : ENGAGED
Bottom Back Card : ENGAGED
The following example shows the results displayed by the dspapsbkplane command when the APS
connector is not place:
M8850_LA.1.AXSM.a > dspapsbkplane
Line-ID Primary Card Signal Status Secondary Card Signal Status
Slot #1 Slot #2
1.1 PRESENT ABSENT
1.2 ABSENT ABSENT
2.1 PRESENT ABSENT
2.2 ABSENT ABSENT
Remote Front Card : ABSENT
Top Back Card : ENGAGED
Bottom Back Card : NOT-ENGAGED
Note The dspapsbkplane command should be used only when the standby card is in the Ready state. When
the standby card is booting or fails, intercard APS cannot work properly, and the dspapsbkplane
command displays “NOT ENGAGED.”
If the dspapsbkplane command displays the message “APS Line Pair does not exist,” suspect that the
APS is not configured on a line.
If the dspapsbkplane command shows different values for each of the two cards, suspect that the APS
connector is seated properly on one card but not on the other.
The APS connector status is the same for all lines in a single bay because the APS connector
interconnects two back cards within the same bay. You need to enter the dspapsbkplane command only
once to display the APS connector status for both upper and lower bays.
Enter the dspapslns command to verify APS configuration. If the working and protection lines show
OK, both lines are receiving signals from the remote note.
Configuring Intercard APS Lines
In AXSM and AXSM/B intercard APS, either front card can be active, and can be connected to either
APS line through the APS connector joining the two back cards. The following process describes how
intercard APS communication works:
1. The signal leaves the front card at the remote end of the line.
2. The signal passes through the APS connector and both back card transmit ports at the remote end of
the line.
3. The signal travels through both communication lines to the receive ports on both back cards at the
local end.
4. The active front card processes the signal that is received on the active line.
5. The standby card monitors only the status of the standby line.
6. If necessary, the signal passes through the APS connector to the front card.
Note The front card monitors only one of the receive lines.