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Re: Muni fiber: L1 or L2?


From: Scott Helms <khelms () zcorum com>
Date: Sat, 2 Feb 2013 22:17:24 -0500

If the goal is the minimize the capital outlay of a greenfield
build, your model can be more efficient, depending on the geography
covered.  Basically you're assuming that the active electronics to
make a ring are cheaper than building high count fiber back to a
central point.  There are geographies where that is both true, and
not true.  I'll give you the benefit of the doubt that you're model is
cheaper for a majority of builds.


Agreed, there are definitely scenarios where home running everything makes
sense.


On the other hand, I am not nearly as interested in minimizing the
up front capital cost.  It's an issue, sure, but I care much more
about the total lifecycle cost.  I'd rather spend 20% more up front
to end up with 20-80% lower costs over 50 years.  My argument is
not that high count fiber back to a central location is cheaper in
absolute, up front dollars, but that it's at worst a minimal amount
more and will have neglegable additonal cost over a 40-80 year
service life.


Here's the thing, over the time frame your describing you're probably going
to have to look at more fiber runs just because of growth in areas that you
didn't build for before.  Even if you nail the total growth of homes and
businesses in your area your chances of getting both the numbers right
_and_ the locations are pretty slim. Also, you're going to have to replace
gear no matter where it is core or nodes on a ring.  Granted gear that
lives in a CO can be less expensive but its not that much of a difference
(~1% of gear costs).  Having a ring topology is basically the best way
we've come up with as of yet to hedge your bets, especially since you can
extend your ring when you need.






--
       Leo Bicknell - bicknell () ufp org - CCIE 3440
        PGP keys at http://www.ufp.org/~bicknell/




-- 
Scott Helms
Vice President of Technology
ZCorum
(678) 507-5000
--------------------------------
http://twitter.com/kscotthelms
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