[c-nsp] XENPAK packet loss

Marian Ďurkovič md at bts.sk
Tue Jun 16 11:50:56 EDT 2009


On Tue, 16 Jun 2009 16:19:08 +0200 (CEST), Mikael Abrahamsson wrote
> On Tue, 16 Jun 2009, FF wrote:
> 
> > I thought Chromatic Dispersion is distance related. This is supposed
> 
> Yes it is.
> 
> > to be SMF-28 DSF, the optics are supposed to be 80km (XENPAK DWDM 1600
> > ps dispersion tolerance). Do you need a DCU even when operating within
> > that range? One of the links is only about 40-50km.
> 
> Well, you didn't say the links were DC or not, and you didn't say how 
> long the link was. At 40-50km, CD is most likely not the cause of your 
> problems.
> 
> According to some info I found, SMF-28 DSF still has 17.1ps/nm/km, 
> meaning your 1600ps dispersion tolerance only gets you 94km? I might 
> be wrong though, I can't get the whole article, google only displays 
> from its cache.

Wait, if it's really DSF, it has zero dispersion at 1550 nm.
But such fiber is unsuitable for DWDM operation.

If it's NZDSF, it should have ~ 4 - 6 ps/nm/km.

    M.



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