Cisco ONS 15454 - 1.6 Troubleshooting FC_MR Circuit Paths With Loopbacks

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Cisco ONS 15454 Troubleshooting Guide, R8.5
November 2009
Chapter 1 General Troubleshooting
1.6 Troubleshooting FC_MR Circuit Paths With Loopbacks
1.6 Troubleshooting FC_MR 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. FC_MR loopback tests
differ from electrical, optical, and Ethernet testing because loopback testing does not require circuit
creation. FC_MR client ports are statically mapped to the trunk ports so no signal needs to traverse the
cross-connect card (in a circuit) to test the loopback.
You can use these procedures on fibre channel data storage (FC_MR) cards. The example in this section
tests an FC_MR circuit on a three-node BLSR. 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 seven network test procedures:
Note FC_MR card client ports do not appear in the Maintenance > Loopback tabs unless they have been
provisioned. Provision ports in the card view Provisioning > Pluggable Port Modules tab. For
information about provisioning client ports, refer to the Cisco ONS 15454 Procedure Guide.
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 FC_MR port
2. A terminal loopback on the source-node FC_MR port
3. A facility loopback on the destination-node FC_MR port
4. A terminal loopback on the destination-node FC_MR port
Note Facility, hairpin, and terminal loopback tests require on-site personnel.
1.6.1 Perform a Facility Loopback on a Source-Node FC_MR Port
The facility loopback test is performed on the node source port in the network circuit. In the testing
situation used in this example, the source muxponder or transponder port in the source node. Completing
a successful facility loopback on this port isolates the FC_MR port as a possible failure point.
Figure 1-38 shows an example of a facility loopback on a circuit source FC_MR port.
Figure 1-38 Facility Loopback on a Circuit Source FC_MR Port
Source
ONS Node
Destination
ONS Node
FC_MR OC-NXC OC-N FC_MRXC
Test Set
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