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Cisco ONS 15800 Series DWDM Platforms

Field Notice: FN - 13592 - Certain Cisco ONS15800/15801 Amplifier Units May Fail While in Service


Revised September 11, 2006

October 3, 2001

NOTICE:

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.


Products Affected

Product

Top Assembly

Comments

RBA-10G

800-10204-02

Any units that have this assembly number and revision or have older assembly numbers and revisions are affected.

RBA-10G-E

800-14497-01

Any units that have this assembly number and revision or have older assembly numbers and revisions are affected.

RBA

800-09740-02

Any units that have this assembly number and revision or have older assembly numbers and revisions are affected.

Problem Description

It is possible that the amplifier units listed above may fail while in service. The likelihood of this occurrence within a space of time is directly associated with the power output level configured on the amplifiers.

The higher the output power of the unit, the faster the unit will age. Operating the unit in an environment where it is subjected to high ambient operating temperatures will accelerate this process.

Background

This problem occurs due to a component of the unit not functioning within expected tolerances.

The amplifiers can be configured for high power, medium power or low power output. The configuration of power level depends upon the number of channels that the amplifier is servicing (and on other network parameters, such as the span budget and the fiber type).

The setting can be checked using any of the Cisco Photonics Element Managers or the Cisco Photonics Local Terminal (CPLT) local craft terminal. The failure rate of the amplifiers is based directly against their power settings:

The failure rate of the amplifiers is based directly against their power settings:

  • At high power, the fail rate will increase by a value of few percent per month, after a period of 6 months to 1 year from turn-up.

  • At medium power, the fail rate will increase by a value of few percent per month, after a period of 18 months to 3 years from turn-up.

  • At low power, this phenomenon is not expected to impact significantly the predicted mean time between failures (MTBF) of the amplifiers.

Problem Symptoms

The problem is shown at unit level when the Output Power Degrade alarm is present, in absence of any other alarm. When the degradation is present, the amplifier continues to work, although with degraded performance; the consequences at network level (i.e., bit error rate (BER) increase) depend on the margin of the specific link. The Output Power value (detected through Supervision) gives an immediate indication of the level of degradation.

Workaround/Solution

To extend the expected lifespan of these units, the configuration should be examined to ensure that the units are operating at the lowest power output level required for the installation. Additionally, the units should be in an environmentally controlled environment where the ambient temperature can be regulated.

To resolve this issue, the amplifier units will need to replaced by units that have the component which operates within the expected tolerances for high power output.

How To Identify Hardware Levels

All units deployed prior to release of this notice will be affected. Units deployed after release of this notice will not have this issue.

Units with a new pump combiner will have the following part numbers (or later):

  • RBA: 800-09740-03 -A0

  • RBA-10G: 800-10204-03 -A0

  • RBA-10G-E: 800-14497-03 -A0

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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