Fiber cut in SF area

Shane Ronan sronan at fattoc.com
Mon Apr 13 22:30:04 UTC 2009


This all implies that the majority of fiber is in "tunnels" that can  
be monitored. In my experience, almost none of it is in tunnels.

In NYC, it's usually buried in conduits directly under the street,  
with no access, except through the man holes which are located about  
every 500 feet.

In LA, a large amount of the fiber is direct bored under the streets,  
with access from hand holes and splice boxes located in the grassy  
areas between the street and the side walks.

Along train tracks, the fiber is buried in conduits which are direct  
buried in the direct along side the train tracks, with hand holes  
every 1000 feet  or so.

In any of these scenarios, especially in the third, where the fiber  
might run through a rural area with no road access and no cellphone  
coverage. Simply walk through the woods to the train tracks, put open  
a hand hole and snip, snip, snip, fiber cut.

Shane Ronan

On Apr 13, 2009, at 5:54 PM, Peter Beckman wrote:

> On Mon, 13 Apr 2009, chris.ranch at nokia.com wrote:
>
>> I get the feeling you haven't deployed or operated large networks.
>
> Nope.
>
>> You never did say what the multiplier was.  How many miles or  
>> detection
>> nodes there were.  Think millions.  The number that popped into my  
>> head
>> when thinking of active detection measures for the physical network  
>> is
>> $billions.
>
> It depends on where you want to deploy it and how many miles you  
> want to
> protect.  I was thinking along the lines of $1.5 million for 1000  
> miles of
> tunnel, equipment only.  It assumes existing maintenance crews would
> replace sensors that break or go offline, and that those expenses  
> already
> exist.
>
>> All for a couple of minutes advanced notice of an outage?  Would it
>> reduce the risk?  No.  Would it reduce the MTBF or MTTR?  No.  Of all
>> outages, how often does this scenario (or one that would trigger your
>> alarm) occur?  I'm sure it's down on the list.
>
> What if you had 5 minutes of advanced notice that something was  
> happening
> in or near one of your Tunnels that served hundreds of thousands of  
> people
> and businesses and critical infrastructure?  Could you get someone  
> on site
> to stop it?  Maybe.  Is it worth it?  Maybe.
>
> Given my inexperience with large networks, maybe fiber cuts and  
> outages
> due to vandals, backhoes and other physical disruptions are just  
> what we
> hear about in the news, and that it isn't worth the expense to  
> monitor for
> those outages.  If so, my idea seems kind of silly.
>
>> SLA's account for force de majure (including sabotage), so I really  
>> doubt
>> there will be any credits.  In fact, there will likely be an uptick  
>> on
>> spending as those who really need nines build multi-provider multi- 
>> path
>> diversity.  Here come the microwave towers!
>
> *laugh* Thank goodness for standardized GIS data. :-)
>
> ---------------------------------------------------------------------------
> Peter Beckman                                                   
> Internet Guy
> beckman at angryox.com                                 http://www.angryox.com/
> ---------------------------------------------------------------------------
>





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