[NANOG] DWDM More Details

John Lee john at internetassociatesllc.com
Fri Apr 25 18:28:47 UTC 2008

Yes, but in very specific cases such as older ZD, NZD fiber and SMF with 20 or more lambdas (at 2.5 Gbps or less) and with Ultra long haul and ultra DWDM 600 - 800 miles, 25 nm spacing and fiber with too high a water vapor content and/or higher impurities in the fiber. If you have less than optimum fiber you need the additional optics and electronics to make it perform.

So my question is the same as the underliying one in your presentation which for Scott is what are you trying to do and there are several ways to reduce the cost or if you need the super neat, highest speed, longest run stuff you will pay for it.

Side note, I liked your two presentations.

From: Alex Pilosov [alex at pilosoft.com]
Sent: Friday, April 25, 2008 1:58 PM
To: John Lee
Cc: Scott E. MacKenzie; NANOG
Subject: RE: [NANOG] DWDM More Details

On Fri, 25 Apr 2008, John Lee wrote:

> In your talk, I agree that the CAN with your CWDM is not that expensive
> but you also mention that the tighter DWDM with long haul optics is
> expensive ie "Everybody knows how to do (active) xWDM by giving a lot of
> money to (insert vendor of choice]:"
> When you talk about the tighter itu spacing for "real" DWDM and the
> lasers with fiber that can handle the power, jitter, chromatic
> dispersion et al. the optics you mention will not handle that.
> We have all duct taped optical systems on campus for the lab "and across
> the state of Georgia" see the Peach Net map.
> What is the largest number of lambdas you have actually run on a single
> fiber with your duct tape system and how bad was the optical cross talk?
I'd be curious to ask reverse question, did anyone *have* real problems
deploying duct tape systems, or power jitter chromatic dispersion is
vendor mumbo jumbo designed to make you buy their gear?

(within the distance limits spec'd, 80km dwdm etc)


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