[c-nsp] Cleaning fibre reduces latency ??

[kevin gannon]

We had a problem on our network where we have 2 STM4's run over the same
fibre and DWDM equipment. The 2 STM's terminate on identical 7606's. One
ran at 5ms and another at 12ms without load.

There were no transmission errors seen or no errors on a "show controls pos
x/y".
On cleaning the fibres into the router with the higher latency it seem to
fix the
issue. A hard loop with a different cable showed a the latency to be normal.

Anyone have any idea what might have caused this given we saw no errors
on the controller ?

Thanks & Regards
Kevin