Ah, single reach wasn't my intention. The point I tried to make was that if 10km and 40km is very near in price, and 3km is considerably cheaper, then it makes more sense to do 3km and 40km reaches to get two distinct prices and reaches.
The 40km/10km cost ratio is between 1.6x and 2x, depending on the
source.
The 10km/4km cost ratio is between 1.15x and 1.3x, again depending on
the source.
Chris
Thus spake "Chris Cole" <chris.cole@finisar.com>
The 40km/10km cost ratio is between 1.6x and 2x, depending on
the source.The 10km/4km cost ratio is between 1.15x and 1.3x, again
depending on the source.
If those numbers translate into prices (not costs), then I'd prefer to see 40km and 4km optics, with no 10km optics. The important point is that the 40km optics neet to be able to handle 4.1km links with no attenuators, preferably without any human tuning at all. You only pay the extra capital cost once (if there even is any, due to more volume of fewer parts), but you pay labor and sparing over and over.
S
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking
So, assuming this translates roughly to optics being:
$1,000 4km
$1,300 10km
$2,600 40km
You'd rather have to pay $2,600 for all your campus links than
$1,300 for all your LAN links?
My preference would be quite different. I'd much rather pay $1,300 for
the LAN links than $2,600 for the Campus links.
Owen
The 40km optics will require optical attenuators for distances somewhere
below 20km, possibly for 10km or less. They will certainly require
optical attenuators for 4km distances.
Chris
Owen,
You are an optimist. Initially, the pricing will be more then an order
of magnitude higher. 
Chris
Chris,
Those were straw-man numbers. The point is that eventually it all
becomes a commodity and mass-produced, and I'd like to see the stuff
that would be maximally useful to us be the commodity that benefits
most from the mass production. Hence my preference for the 10km optics.
---rob
"Chris Cole" <chris.cole@finisar.com> writes: