IEEE 40GE & 100GE

Chris Cole chris.cole at
Thu Dec 13 23:48:38 UTC 2007

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.


-----Original Message-----
From: Stephen Sprunk [mailto:stephen at] 
Sent: Thursday, December 13, 2007 1:52 PM
To: Chris Cole; Mikael Abrahamsson
Cc: North American Noise and Off-topic Gripes
Subject: Re: IEEE 40GE & 100GE

Thus spake "Chris Cole" <chris.cole at>
> 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
40km and 4km optics, with no 10km optics.  The important point is that
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
cost once (if there even is any, due to more volume of fewer parts), but
pay labor and sparing over and over.


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 

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