Fiber cut - response in seconds?

Charles Wyble charles at
Mon Jun 1 23:58:21 UTC 2009

Joel Jaeggli wrote:
> Charles Wyble wrote:
>> Joel Jaeggli wrote:
>>> It's pretty trivial if know where all the construction projects on your
>>> path are...
>> How so? Setup OTDR traces and watch them?
> When you lose link on every pair in a bundle, but don't lose any of the
> buildings you're serving via diverse paths, you have a pretty good idea
> what happened. Knowing which of the three construction projects on that
> path is likely to be digging a trench is a facilities issue.

Right. So why the "near instant" response time. If it's a diverse path, 
one would imagine that they could respond in a few hours or a day and 
not have any impact.

The fact that they are so closely monitoring the construction and 
wanting to fix it that fast seems a bit over the top for redundant systems.

>>> I've seen this happen on a university campus several times. no black
>>> helicopters were involved.
>> Care to expand on the methodology used? A campus network is a lot
>> different then a major metro area.
> Given the location the guys in the blacks suvs likely have at least
> situational awareness of all of the contruction projects in their
> immediate vicinity. 

One would hope. Though given the archaic nature of many govt systems, 
that could involve a lot of manual paper pulling... or are the 
bid/reward/permit systems all automated on the east coast? :)

they don't have to monitor everyone's cable, just
> their own and near instantaneous response implies proximity so it may
> well be more akin to a campus network.


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