Feac Alarms - Cisco ONS 15454 Troubleshooting Manual

Chapter 1 General Troubleshooting
1.4.2 DS-3I Inhibit Loopback
DS-3E and DS-3I cards respond to (but do not send) DS-3-level FEAC codes. You can inhibit FEAC
response on ports for these cards using the Inhibit Lbk check box on their Maintenance windows.
1.4.3 DS3XM-6 Inhibit FEAC Loopback
DS3XM-6 ports and transmuxed DS-1s initiate loopbacks when they receive FEAC Line Loop Codes. If
the Inhibit FE Lbk check box is checked for a DS-3 port, that port ignores any FEAC Line Loop Codes
it receives and will not loop back (return them). Only DS-3 ports can be configured to inhibit FEAC
loopback responses; individual DS-1 ports (accessed on the DS3XM DS1 tab) cannot inhibit their
responses. If you inhibit a DS-3 port's far end loopback response, this DS-3 port and the DS-1 lines it
contains are not restricted from terminal (inward) or facility (line) loopbacks.

1.4.4 FEAC Alarms

When an ONS 15454 port receives an activation code for a FEAC loopback, it raises the
LPBKDS1FEAC
command to deactivate the FEAC loopback. If a node sends a FEAC loopback command to the far end,
the sending node raises a
1.5 Identify Points of Failure on an Optical Circuit Path
Facility (line) loopbacks, terminal (inward) loopbacks, and cross-connect loopback circuits are often
used together to test the circuit path through the network or to logically isolate a fault. Performing a
loopback test at each point along the circuit path systematically isolates possible points of failure.
You can use these procedures on OC-N cards, G-Series Ethernet cards, transponder (TXP, TXPP) cards,
and muxponder (MXP) cards. The example in this section tests an OC-N circuit on a three-node BLSR.
Using a series of facility (line) loopbacks and terminal (inward) loopbacks, the example scenario traces
the circuit path, tests the possible failure points, and eliminates them. The logical progression contains
seven network test procedures:
Note The test sequence for your circuits will differ according to the type of circuit and network topology.
1.
2.
3.
4.
5.
6.
7.
All loopback tests require on-site personnel.
Note
November 2004
or LPBKDS3FEAC
LPBKDS1FEAC-CMD
A facility (line) loopback on the source node OC-N (or G-Series, TXP, or MXP) port
A terminal (inward) loopback on the source node OC-N (or G-Series, TXP, or MXP) port
A cross-connect loopback on the source OC-N port
A facility (line) loopback on the intermediate node OC-N (or G-Series, TXP, or MXP) port
A terminal (inward) loopback on the intermediate node OC-N (or G-Series, TXP, or MXP) port
A facility (line) loopback on the destination node OC-N (or G-Series, TXP, or MXP) port
A terminal (inward) loopback on the destination node OC-N (or G-Series, TXP, or MXP) port
condition. The condition clears when the port receives the
or a LPBKDS3FEAC-CMD
Cisco ONS 15454 Troubleshooting Guide, R4.6
1.4.2 DS-3I Inhibit Loopback
condition for the port.
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