[c-nsp] Good 10GE Metro switch

[Gert Doering]

Hi,

On Mon, Aug 11, 2008 at 05:08:23PM -0400, Joe Loiacono wrote:
> PS - Should I worry (alot) about being at or slightly above the 40 Km 
> distance?

The key question is, how much loss (in dB) do you have on that line, and
on the tolerances of the X2 optics in question - a "best case" X2 will
transmit with +4.0 dBm, while a "worst case" X2 will transmit with -4.7 dBm,
according to:

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/hardware/Module_Installation/Mod_Install_Guide/0btransc.html

- so with a receiver sensitivity of -15.8 dBm, you have a power budget of
11.1 dB to 19.8 dB.   11.1 dB is very tight for a 40km span - you need good
fibers, and nearly no patches in between (every patch brings about 0.5 dB 
loss).

You need to ask your carrier about the attenuation of the fiber path.

gert

-- 
USENET is *not* the non-clickable part of WWW!
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Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de
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