nanog mailing list archives
Re: Fiber cut - response in seconds?
From: Deepak Jain <deepak () ai net>
Date: Mon, 01 Jun 2009 19:43:10 -0400
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.
Current thread:
- Fiber cut - response in seconds? Charles Wyble (Jun 01)
- RE: Fiber cut - response in seconds? Warren Bailey (Jun 01)
- Re: Fiber cut - response in seconds? Joel Jaeggli (Jun 01)
- Re: Fiber cut - response in seconds? Charles Wyble (Jun 01)
- Re: Fiber cut - response in seconds? Deepak Jain (Jun 01)
- Re: Fiber cut - response in seconds? Joel Jaeggli (Jun 01)
- Re: Fiber cut - response in seconds? Charles Wyble (Jun 01)
- Re: Fiber cut - response in seconds? Jason Fesler (Jun 01)
- Re: Fiber cut - response in seconds? Dave Pooser (Jun 01)
- Re: Fiber cut - response in seconds? Charles Wyble (Jun 01)
- Re: Fiber cut - response in seconds? Dave Wilson (Jun 02)
- RE: Fiber cut - response in seconds? Deepak Jain (Jun 02)
- Re: Fiber cut - response in seconds? Martin Hannigan (Jun 02)
- Re: Fiber cut - response in seconds? Charles Wyble (Jun 02)
- Re: Fiber cut - response in seconds? Valdis . Kletnieks (Jun 02)
- Re: Fiber cut - response in seconds? Charles Wyble (Jun 01)