nanog mailing list archives

Re: FCCs RFC for the Definition of Broadband


From: Jack Bates <jbates () brightok net>
Date: Thu, 27 Aug 2009 09:57:56 -0500

Leo Bicknell wrote:
So while mileage per subscriber increases, cost per mile dramatically
increases.  The only advantage in an urban enviornment is that one
trench may serve 200 families in a building, where as a rural trench
may serve 20 familes.

Cost per subscriber is the only cost that matters. That is what defines your recoup time and profit margins. BTW, in many cases it's actually cheaper to bore the entire way then intermix boring and trenching. And out here, they are heavily against you trenching right through someone's driveway or a road. Then there's the rivers and creeks.

But more puzzling to me is the idea that fiber becomes uneconomic.
This may have once been true, but right now you can buy 10km or
even 40km lasers quite cheaply.  Compare with copper which for even
modest speeds requires a repeater every 2-4km.

Maintenance. The reason rural companies prefer active equipment in the plant is because of maintenance. 20 splices to restore service to 20 customers vs 1 splice to restore service to 20 customers. This is oversimplified, in reality, many of the FTTH comments in this thread imply bringing all customers back to the CO to keep active equipment out of the plant. This will tend to imply large fiber bundles leaving the CO and breaking down smaller and smaller as you get further from the CO. A large fiber cut may mean 128+ splices to restore service at 1 splice per customer.

In addition, it throws away all the money and investment of plant already in the ground from key points to the customers. I haven't seen an installation running repeaters for copper. More common is a remote system fed by a fiber ring (so when the 20km fiber is cut, service isn't lost while repairs are done) and the last 1.5 miles fed by copper which is already there.

with GigE speeds today with no intermediate equipment; the cost of
a 20km GBIC is far less than the cost of installing 4 repeaters.


If someone is setting up like this, I'd agree. More common:

Traditional POTS was often served off double ended carrier and load coils, which later became fiber fed integrated carrier with gr303 and load coils. Cheapest solution, replace carrier with DSL capable carrier, remove load coils when not necessary and extend from there for closer carriers where applicable (shorten copper loops, and removal of more load coils).

Here locally, we dropped over 90% of our load peds. Only the furthest reaches still have them and of course cannot get DSL.

There's plenty of infrastructure built every day with ROI's of 20 years.

Hope they have disaster insurance. A good tornado or wildfire (or backhoe) can do some serious damage. I had both this year in Lone Grove. Fun. Fun. Fiber rings to remote field equipment still gives the best redundancy and maintenance cost (as there is less to splice over the longhaul to the remote system).

service is $5 per month.  It's a 33 year ROI.  That's ok with me, it's
infrastructure, like a road, or a bridge.  We're still using copper in
the ground put in during the 60's, 70's, and 80's.

You bet. We're also using fiber and copper put in the ground yesterday. Copper is amazingly resilient. Most of the copper that has to be replaced is old aircore in the ground (which is why aircore shouldn't be in the ground, as it collects water and leads to shorts over long distances) or rehab of aircore in aerial due to bad boots that weren't maintained. The switch to fiber fed remote systems abandoned most of the problematic copper, though.


Jack


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