nanog mailing list archives

Re: DWDM on 250 Km dark fiber without re-amplification


From: Faisal Imtiaz <faisal () snappytelecom net>
Date: Sun, 25 Dec 2016 00:53:00 +0000 (GMT)

I agree with what Baldur suggested..

Only thing I would point out that .. 
Hardly anyone installs 200km fiber runs without having some sort of a Regen facility.

While you can push the signal over the 200km link, in the long run you may be better off see if there a Regen facility 
(typically 70/80km) that you can use to re-generate the light.

Best of luck.

Faisal Imtiaz
Snappy Internet & Telecom


----- Original Message -----
From: "Baldur Norddahl" <baldur.norddahl () gmail com>
To: "nanog list" <nanog () nanog org>
Sent: Saturday, December 24, 2016 2:30:40 PM
Subject: Re: DWDM on 250 Km dark fiber without re-amplification

Hello

I have not done this as our links are not that long. However in theory
this is how I would do it. There are nice integrated solutions that will
do it as a black box, but someone else will have to tell you about that.
I am using Fiberstore as a reference because they have the necessary
components with pricing directly online, but there is of course multiple
alternatives.

So first off forget about 40G and 100G. This will be N x 10G and N can
be as large as 96 channels. 100G would be the same equipment (possibly
without dispersion compensation) but with each 100G stream as four 25G
wavelengths. However the optics are very expensive and hard to get for
40G and 100G while 10G is relatively cheap and easy.

You need the following components:

http://www.fs.com/support/dwdm-edfa-amplifier-for-long-haul-applications-100

They list all you need with a nice drawing. Get the components from them
or someone else. The nice integrated solutions are just these components
in a box.

They only list the solution as 200 km. You will have to send them a mail
and ask if they can do 225 km.

Also you need to check that the black fiber provider allows amplified
signals at this level. Not everyone do. Normally the signals are not
that dangerous, but with this a unaware tech can go blind if he is
unlucky. It is not clear if the Fiberstore equipment automatically turns
of the laser in the case of a fiber cut and that might also be a
requirement.

Regards,

Baldur



Den 24/12/2016 kl. 01.14 skrev Jeremy:
Hi all,

First, i'm sorry for my english, i'm french and i don't have a good
level in this language. But i want some informations and i'm sure,
someone will be give the good anwser about my question.

So, i'm regarding to rent a dual dark fiber in France, the estimated
distance is 225 Km, but i know there are a lot of optical switching on
the highway where it's fiber is installed (in theory, all 80 Km). So,
i used the bad scenario, in adding 25 Km on my need.

I would like to buy a amplificator and multiplexer DWDM to add some
10Gb/s waves on this dark fiber. I've see that the amplification is
better on 100 Gb/s synchronised ports, but we don't have enoug
capacity on our router to add 100 Gb/s interfaces.

So, someone has installed this type of hardware on a dark fiber
without regeneration  on 250 Km of distance ?
If yes, with what kind of hardware ? If you are commercial for this
hardware, please contact me in private message.

Thanks you for your time,
Jérémy
AS197922


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