Hmm even most urban environments aren't worth deploying in or are probably marginal profit. So I would expect 30-45% of population of the US to not be worth or marginally worth deploying. I am assuming most urban less than 250k and probably spread out. Not to mention to provide transit without services to residential is a margins game to begin with and without at least a 20-30% take rate it probably isn't worth the cost of l3 infrastructure. On the other hand for actual dense urban environments it makes perfect sense as long as the are willing to maintain it. I see the possibilities, but have a gut feeling it would become a political mess and unreliable, not to mention cost us more than we pay now. -- Sent from my Android phone with K-9 Mail. Please excuse my brevity. Leo Bicknell <bicknell@ufp.org> wrote: In a message written on Sun, Mar 25, 2012 at 05:29:04PM +0100, Nick Hilliard wrote:
most of the expense of laying fibre is associated with ducting + wayleave. Once you have that in place, blowing new fibre is relatively inexpensive. So rather than amortising the cost according to the lifetime of the fibre, it makes much more sense to amortise over the lifetime of the ducting.
Maybe. In rural deployments it's much more likely the fiber is aerial, it's far cheaper to attach to existing poles with few cables on them than it is to bury the fiber. Even in urban areas where buried duct is the norm, being able to use old ducts varies a lot with the geography and how active the area is to other development. I've seen plenty of ducts where it had been cut and repaired several times before use that running a new cable through it was impossible and it simply had to be replaced. In other locations 20 years later a new cable goes through like butter. But I think it's all a bit of a tangent; when talking about _residential_ fiber it's prudent to run 2-6 strands to every home day one, and then, well, there's basically never a point in running more. The chance of blowing more fiber down the duct later is near zero. It's also why I'm not a fan of *PON schemes, eliminate the splitter and run a single star topology. 20 years from now Petabit optics will look different than today's GigE in some way, but I'll bet money they are tuned to run on single mode fiber. They may not like the splitters and the like though. By doing a star back to a wiring center you enable all technologies. GPON today, direct GigE or 10GE where necessary, and all future technologies. -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/