Communications between the TCC and some versions of the 15454-FTA3-T fan tray can be disrupted by internal system noise.
This fault is precipitated when external electrical noise is present in the system.
This issue will not occur when using TCC+, FTA3 version -01 or FTA-CC. This issue is reduced with FTA3 version -04 or with software versions 188.8.131.52, 5.0.8, 6.0.2, 7.0.4, 7.2.2, and 8.0.0.
The issue is entirely resolved in software versions 7.0.5, 6.0.3, 7.2.3, and 8.5.
TCCs were resetting at a customer sites for no obvious reason. Traffic was not impacted.
Under lab test conditions it was discovered that electrical noise emissions from two small cables within the Fan Tray assembly was causing the TCC to reset.
The TCC resets repeatedly for no apparent reason, but the system continues to operate normally.
A software change has been implemented to alleviate the TCC resets. CTC Software releases that have a partial fix are:
Software releases with a complete fix are: 7.0.5, 6.0.3, 7.2.3 and 8.5.
The TCC will now automatically recheck the fan tray communication channel rather than resetting.
Upgrading to any of the above software releases should correct this condition.
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How To Identify Hardware Levels
Check the Products Affected section at the top of this Field Notice.
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