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Cisco ONS 15310-CL and Cisco ONS 15310-MA Troubleshooting Guide, R7.0
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Chapter 1 General Troubleshooting
1.5.1 FEAC Send Code
Note
The term "Far End" refers to the equipment connected to the WBE card and not to the far end of a circuit.
1.5.1 FEAC Send Code
The Send Code column on the WBE-28/WBE-84
card Maintenance tab only applies to OOS-MA,MT
ports configured for ESF framing. The column lets a user select No Code (the default) or line loop code.
Selecting line loop code inserts a line loop activate Far End Loopcode in the ESF overhead transmitting
to the connected facility. This code initiates a loopback from the facility to the ONS 15454. Selecting
No Code sends a line-loop-deactivate Far End Loopcode to the connected equipment, which will remove
the loopback.
1.5.2 WBE-28/WBE-84 Inhibit FEAC Loopback
WBE-28/WBE-84
DS1 ports initiate loopbacks when they receive Far End line loop codes. If the Inhibit
FE Lbk check box is checked for a DS1 port, that port ignores any Far End line loop codes it receives
and will not loop back. If you inhibit a DS1 port's far end loopback response, this DS1 port is not
restricted from terminal or facility loopbacks.
1.6 Troubleshooting Ethernet Circuit Paths With Loopbacks
Facility loopbacks, terminal 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.
When performing this testing on networks that contain intermediate nodes, you will test the OC-N
connection at intermediate nodes rather than CE100T-8 card connections. (The CE100T-8 is a mapper
card and is only capable of supporting point-to-point circuits.)
You can use these procedures on CE100T-8 cards but not on ML-100T-8 Ethernet cards. Using a series
of facility loopbacks and terminal loopbacks, the example scenario traces the circuit path, tests the
possible failure points, and eliminates them. The logical progression contains six network test
procedures:
Note
The test sequence for your circuits will differ according to the type of circuit and network topology.
1.
A facility loopback on the source-node Ethernet port
2.
A terminal loopback on the source-node Ethernet port
3.
A facility loopback on the intermediate-node OC-N port
4.
A terminal loopback on the intermediate-node OC-N port
5.
A facility loopback on the destination-node Ethernet port
6.
A terminal loopback on the destination-node Ethernet port
Note
Facility and terminal loopback tests require on-site personnel.
