Specifications

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Cisco ONS 15454 Troubleshooting and Maintenance Guide
November 2001
Chapter 2 General Troubleshooting
2.4 Circuits and Timing
This section provides solutions to circuit creation and reporting errors, as well as common timing
reference errors and alarms.
2.4.1 AIS-V on DS3XM-6 Unused VT Circuits
An incomplete circuit path causes an alarm indications signal (AIS); for example, when the port on the
reporting node is in-service but a node upstream on the circuit does not have an OC-N port in-service.
An AIS-V indicates that an upstream failure occurred at the virtual tributary (VT) layer. AIS-V alarms
also occur on DS3XM-6 VT circuits that are not carrying traffic and on stranded bandwidth.
Procedure: Clear AIS-V on DS3XM-6 Unused VT Circuits
Step 1 Determine the affected port.
Step 2 Record the node ID, slot number, port number, or VT number.
Step 3 Create a unidirectional VT circuit from the affected port back to itself. For example, Source node/Slot
2/Port 2/VT 13 cross connected to Source node/Slot 2/Port 2/VT 13.
Step 4 Uncheck the bidirectional box in the circuit creation window.
Step 5 Give the unidirectional VT circuit an easily recognizable name, such as delete me.
Step 6 Display the DS3XM-6 card in CTC card view. Click the Maintenance > DS1 tabs.
Step 7 Locate the VT that is reporting the alarm (for example, DS3 #2, DS1 #13).
Step 8 From the Loopback Type list, choose Facility (line) and click Apply.
Step 9 Click Circuits.
Step 10 Find the one-way circuit you created in Step 2. Select the circuit and click Delete.
Step 11 Click Yes in the Delete Confirmation box.
Step 12 Display the DS3XM-6 card in CTC card view. Click Maintenance > DS1.
Step 13 Locate the VT in Facility (line) Loopback.
Step 14 From the Loopback Type list, choose None and then click Apply.
Step 15 Click the Alarm tab and verify that the AIS-V alarms have cleared.
Step 16 Repeat the above steps for all the AIS-V alarms on the DS3XM-6 cards.
2.4.2 Circuit Creation Error with VT1.5 Circuit
You might receive an “Error while finishing circuit creation. Unable to provision circuit. Unable to
create connection object at <node name>” message when trying to create a VT1.5 circuit in CTC.
You may have run out of bandwidth on the VT cross-connect matrix at the ONS 15454 indicated in the
error message. The matrix has a maximum capacity of 336 bidirectional VT1.5 cross-connects. Certain
configurations will exhaust VT capacity with less than 336 bidirectional VT1.5s. Refer to the Cisco ONS
15454 Installation and Operations Guide for more information.