[c-nsp] SFP high power alarm

[Wayne Tucker]

On Tue, Aug 21, 2012 at 3:13 AM, marc williams <marcuk at me.com> wrote:
> 10 GIG cisco compatible SFP in a 3750-X switch.
> we started to see this error message after a fibre break and repair:
>
> %SFF8472-5-THRESHOLD_VIOLATION: Te4/1/2: Tx power high alarm; Operating
> value:   0.6 dBm, Threshold value:   0.0 dBm
>
> Cant see how the TX power can go high? any ideas? Interface is up and
> working ok.

Too much signal can cause receiver saturation, which in turn leads to
errors on the interface.  If you aren't seeing errors then you're
probably OK, but I always prefer to attenuate the signal so the errors
go away.

You can buy attenuators in various sizes, or you can fashion a
temporary one by wrapping the receive fiber around a pencil (the small
radius attenuates the signal).

Is this a long haul optic (10GBASE-ER, ZR, etc.)?

:w