Figure - Cisco ONS 15454 Troubleshooting Manual
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Also See for ONS 15454:
- Procedure manual (850 pages) ,
- Reference manual (728 pages) ,
- Software feature and configuration manual (232 pages)
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Chapter 1
General Troubleshooting
FC_MR-4 card facility loopbacks behave differently from other ONS 15454 cards. With a client-side
facility loopback, the client port service state is OOS-MA,LPBK & MT; however the remaining client
and trunk ports can be in any other service state. For cards in a trunk-side facility loopback, the trunk
port service state is OOS-MA,LPBK & MT service state and the remaining client and trunk ports can be
in any other service state.
Caution
A lock out of protection must be executed before putting a two-fiber or four-fiber bidirectional line
switched ring (BLSR) span into a facility loopback state. That is, a span lockout of one side (such as the
east side) of a two-fiber BLSR is required before operating a facility loopback on the same (east) side of
the ring. A span lockout of one protection side (such as the east protection side) of a four-fiber BLSR is
required before operating a facility loopback on the same (east) side of the ring. If you do not execute
the lockout prior to creating the loopback, the ring can become stuck in an anomalous state after you
release the loopback.
1.1.2 Terminal Loopbacks
The following sections give general information about terminal loopback operations and specific
information about ONS 15454 card loopback activity.
1.1.2.1 General Behavior
A terminal loopback tests a circuit path as it passes through the cross-connect card and loops back from
the card with the loopback.
comes into the electrical port and travels through the cross-connect card to the optical card. The terminal
loopback on the optical card turns the signal around before it reaches the LIU and sends it back through
the cross-connect card to the electrical card. This test verifies that the cross-connect card and terminal
circuit paths are valid, but does not test the LIU on the optical card.
Figure 1-4
Test Set
In CTC, OC-N cards with terminal loopbacks show an icon
on other cards in this release.
Figure 1-5
November 2009
Figure 1-4
shows a terminal loopback on an OC-N card. The test-set traffic
Terminal Loopback Path on an OC-N Card
DS-N
XC
OC-N
Terminal Loopback Indicator
1.1.2 Terminal Loopbacks
(Figure
1-5). Loopback icons are not shown
Cisco ONS 15454 Troubleshooting Guide, R8.5
1-5
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