[114961] in North American Network Operators' Group
Re: Fiber cut - response in seconds?
daemon@ATHENA.MIT.EDU (Deepak Jain)
Mon Jun 1 19:43:28 2009
Date: Mon, 01 Jun 2009 19:43:10 -0400
From: Deepak Jain <deepak@ai.net>
To: Charles Wyble <charles@thewybles.com>
In-Reply-To: <4A245FCD.9050208@thewybles.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Reply-To: deepak@ai.net
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
I'm not sure why this sounds so surprising or impressive... given g$vt
budgets.
Monitoring software using a pair of fibers in your bundle. OTDR or
similar digital diagnostics. You detect a loss, you figure out how many
feet away it is. You look at your map.
A simpler way to do it (if you don't mind burning lots of fiber pairs)
would be to loop up a pair of fibers (or add a reflectance source every
1000 ft or so -- spliced into the cable). You can figure out to within a
thousand feet once you know WHICH set of loops has died.
Given it almost always involved construction crews, you drive until you
see backhoes for your final approximation.
If I were the gov't I'd have originally opted for #2, and then moved to #1.
"Seconds" is just a function of how far away the responding agency's
personnel ( monitoring the loop ) were from the cut. Obviously we are
talking about a few miles tops.
Plenty of people used to have a single pair in each bundle for
"testing". Its relatively trivial to make that a test pair live. This is
all predicated on you actually keeping your toplogy up-to-date.
Deepak Jain
AiNET
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?
>
>>
>> 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.
>
>
>
