Re: DWDM and EDFA and DCM

[Rodrigo 1telecom <rodrigo () 1telecom com br>]

Nothing is wrong with the fiber... Attenuation is good... Gbics specs says -23db as a limit of your sensibility ...i 
have tried to put bidi sfp+ 80km on this fiber and have -25dbi on other side( not connect) this module have -20dbi 
sensibility ...
This scenario have a 4 channels... And i use 2 10gb channels... C21 and c22 on side A and c51 and c52 on side B....

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Grupo Connectoway

> Em 22/04/2015, às 19:01, Evelio Vila <evelio () thousandeyes com> escreveu:
>
> I think the OP is asking about whether it should account for chromatic dispersion or not. Intramodal dispersion may 
> very well be a limit on your link even the power budget (as presented before) is fine.  As Mikael said, I would stick 
> to the specs from the manufacturer for that specific module, or rent an OTDR and make the measurements.
>
> --
> Evelio
>
> > On Wed, Apr 22, 2015 at 1:51 PM, Baldur Norddahl <baldur.norddahl () gmail com> wrote:
> > First: buy a power meter. They are really cheap and the only way to know
> > for sure how much signal you got. It will also tell you how much launch
> > power you have. The fiberstore modules are listed as 0 to +5 dBm launch
> > power - if you got lucky it might be +5 and if you got a lower end module
> > it might be close to 0. Obviously this makes a huge difference for how much
> > power you get on the other end. Also it is said that the laser will lose
> > power over time.
> >
> > Second you need to think in terms of power budget, not distance. So you got
> > 68 km and the module is rated for 80 km - but not all fiber is not born
> > equal. A power meter allows you to measure the true link loss.
> >
> > Third you did not tell what DWDM multiplexer you are using. A 44 channel
> > DWDM multiplexer from Fiberstore can have up to 4.5 dB insertion loss. You
> > might have two of those on your link for a total of 9 dB loss. Your 80 km
> > module has a 23 dB link budget, so this leaves you with 23-9 = 14 dB
> > budget. If your fiber has 0.25 dB loss per km, that is only 56 km.
> >
> > Regards,
> >
> > Baldur