Re: 1G/10G options over 130 km of fiber

[Andrew Gallo <akg1330 () gmail com>]

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On 3/5/2010 3:36 PM, Justin M. Streiner wrote:
> A dark fiber path was recently ordered to a remote location on our
> network, and to my surprise, the engineering report on the path is
> coming back at around 130 km, which is substantially longer than I
> expected the span to be.
>
> While I am researching gear that will drive a signal this far without a
> mid-span regen, I'm also inquiring with the carrier to see if there is
> any way to shorten the span, but I also have to be prepared for the
> chance that a shorter span is not possible.
>
> I've seen some pieces from MRV and Transition that might be up to the
> job, though most of the options I've seen are rated to 120 km, tops.
>
> That said, I'd be interested in hearing about what people who are
> driving similar spans.  I don't think I'm going to have the budget to go
> out and buy Ciena/Infinera/Cisco ONS kit just for this, since I don't
> have any at the present time.  The link is still being built, so I
> haven't gotten an engineering report yet.  My gut tells me that the
> 2-point loss on the span at 1550nm will be somewhere around 30-35 dB.
>
> jms

You have to be real careful running 10G at those distance.  Loss isn't
the only thing you have to worry about...you may need dispersion
compensation, which by itself is going to add to your loss.

If loss is your only worry, then you might be able to do a pre/post
amplification.  130km is far, but you might be able to skip midspan
amplification.


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