This is from a previous thread on the topic of fiber cuts but I thought it fit this discussion well, epsecially since it concerns Verizon. Apologize for not being able to recall who originally posted it - only have the citation. In an August 5th, 2003 court case involving the Maine Public Utility Commission an expert witness from Verizon stated that only 10% of the fiber rings in Maine are fully redundant, and 90% are at least partially collapsed and vulnerable to single cut failures (Maine PUC, 2003) Maine PUC, 2003, “Docket Number 2002243” http://www.state.me.us/mpuc/misctranscripts/2002-243%20080503.htm Appears it should not be a suprise at all it was not redundant. On a related note another researcher at GMU has collected all the outage reports that "were" posted on the FCC website and put them in a database form, and we are going to try and run correlations between outage location and the density of fiber located there. ----- Original Message ----- From: Joe Abley <jabley@isc.org> Date: Friday, May 21, 2004 10:23 am Subject: Re: fiber cut 19 May/PM -> 20 May/AM in Ashburn, VA (lawnmower?!)
On 21 May 2004, at 08:09, Robert E. Seastrom wrote:
sonet, obviously, does not *have* to be in a ring, but it often is. unfortunately, a fair percentage of the time, the additional protection offered by a ring topology is a mirage, due to a configuration known as "collapsed backbone". in this instance, both pairs of fiber ride in the same conduit for some portion of the distance
... or even as two wavelengths on the same pair of fibre.
It's a sick, sick, twisted world.
Joe