The pump laser of the above listed units can experience an initially slow degradation that, after a variable amount of time, becomes quicker and then leads to a catastrophic failure.
Warning: If any customer has already had replacement amplifiers which were shipped to them after May 2002, these units with the above specified serial number ranges have already been upgraded and do not need to be monitored.
Repaired units retain their original serial number, so amplifiers replaced after May 2002 will be done so from reworked ampifiers having serial numbers within the range beginning with the 19th week of May 2000 and ending the 18th week of May 2002. These units are already fixed.
Customers can verify that their units have actually been repaired by checking the unit part number and revision against the table in the Products Affected section.
To correctly identify the serial numbers affected, carefully read section below entitled How To Identify Hardware Levels.
The problem was caused by a change in the production process of the supplier. It is not a design error. The process has now been fixed by a long-term solution. The time after which the degradation becomes evident is variable depending on the Power Class. The higher the Class the shorter the time will be as detailed below.
The laser current increases but this does not change the laser power or the optical amplifier performances. Time to complete this slow part of the process depends on the working power class of the laser:
After this time has elapsed the degradation process becomes quicker and the optical performances are affected. The effect on BBA, which is equipped with just one laser, is obviously catastrophic. The effect on other amplifiers, once that one pump laser fails, is an improper pumping of the Erbium Doped fiber. The output power will very likely decrease by 3 dB. The gain tilt will increase (longer wavelength will show higher gain). The noise figure is impacted slightly on RBA and RBA-10G while it is heavily impacted on TPA-B and BBA-10G when laser one fails.
The solution is to replace the amplifiers to be implemented through the gradual approach detailed in the procedure entitled ONS15800 Amplifiers: Pump Laser Reliability Management.
Network failing cards are to be replaced by customer spares and replaced cards are to be returned using the normal return material authorization (RMA) process.
The possibly affected optical amplifiers have been manufactured starting the 19th week of 2000 (May) and ending the 18th week of 2002 (May). In order to state the manufacturing date the serial number has to be used: the serial number's second and third digits represent the manufacturing year, while the fourth and fifth digits represent the week number. For example: An amplifier with serial number 19903124, has been manufactured during week 03 in 1999. The affected ranges are:
Remember to check the part and revision numbers before the serial number (See the section above entitled Products Affected).
For example: If you have an RBA from the affected serial number range, you can verify whether or not this unit has already been upgraded by checking the Product ID. A part and revision number such as 800-09740-05 will mean the unit has not been upgraded, while 800-09740-06 will mean the unit has been fully upgraded.
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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