[c-nsp] Connecting PoP's with long distance

[Tim Rayner]

Hi Murat & others,

Do you have insertion loss measurements for the individual or combined paths ?  Any measurements should be taken at 1550nm.

EDFA Amplifiers at your intermediate points could work - you would probably get away with EDFA at one point - 80km plus 40km should be quite OK. Depending upon the EDFA Amps and their input power range, you could even boost the signal as you receive it at each end - after 120km - avoiding intermediate active gear altogether.

If the fibre is not too poor, you may also be able to avoid EDFA or intermediate re-gen all-together - I'd suggest trying it as a single "patched-through" link. You need to keep in mind that chromatic dispersion can become an issue for 10Gbps at a distance >= 80km. We've had a 10Gbps link recently of > 110km that didn't work with an 80km optic at 1560.61nm (even though the received power was OK), but worked with an 80km 1530.33nm optic - (dispersion is reduced at the shorter wavelength).

If I was trying this, I'd first try a pair of 100km rated 1550nm optics like these:
http://www.flexoptix.net/en/produkte/transceiver/xfp-zr-transceiver-10-gigabit-stm64-sm-1550nm-100km-25db-ddm-dom.html

Or if dispersion turns out to be the limiting issue, then there is a good chance that a 1470nm version of the CWDM XFP part could do the trick (lower chromatic dispersion at 1470nm than 1550nm, but perhaps slightly higher loss)
http://www.flexoptix.net/en/produkte/transceiver/xfp-cwdm-transceiver-10-gigabit-sm-1270-1610nm-70km-23db-ddm-dom.html
- 1470 will be out of the range where EDFA Amps can help you, but these two options could avoid EDFA all-together.

I'd try one or both of these options - If the link comes up, you can know how much margin you have by reading the DoM stats, or you could check that it still works after inserting say a 2dB attenuator in both the TX and RX path.

Its so much simpler to try it with the longest range optics you can find at each end that I'd strongly favour trying that first - before looking at re-gen at one or both of the intermediate sites, or Amplification either at each and, or at one intermediate site.

Good Luck!

I'd be interested to hear what you try and how it works for you.

Tim.


Tim Rayner
Optical Engineer, AARNet Pty Ltd
street address: Building 9, Banks Street, YARRALUMLA ACT 2600
postal address: GPO Box 1559, CANBERRA ACT 2601
t. +61 2 6222 3575 f. +61 2 6222 3535 e. Tim.Rayner at aarnet.edu.au
w. www.aarnet.edu.au
Network Faults (24x7): 1300 APL NOC (1300 275 662) or noc at aarnet.edu.au

important
This email and any files transmitted with it are confidential, and the rights of confidentiality in such information are not waived or lost by its mistaken delivery to you. Any dissemination, copying, use or disclosure of the email and/or such files without the permission of AARNet, or the sender, is strictly prohibited. If you have received this email in error, please contact the sender immediately and delete all copies of this transmission.

________________________________________
From: cisco-nsp [cisco-nsp-bounces at puck.nether.net] on behalf of Ivan [cisco-nsp at itpro.co.nz]
Sent: Saturday, 6 September 2014 12:14 PM
To: cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Connecting PoP's with long distance

Hi Jared,

This is something I have also been looking at. Is there any particular
brand of XFP you have had success with?

If we take the Cisco "80km" ZR we have TX 0 to 4 dBm and RX -7 to -24
dBm - worst case 24dB budget excluding splices, patches etc. Assuming
0.2dB/km 120km would be right on the limits. I would like to have some
buffer.

Thanks

Ivan

On 5/Sep/2014 1:32 a.m., Jared Mauch wrote:
> You should be able to do 120km with a ZR XFP @ 10G without anything.
>
> If you later want to add equipment to the sites, you can look at doubling your optics and something like this:
>
> http://www.perle.com/products/10-Gigabit-Standalone-Media-Converters.shtml
>
> - Jared
>
>
>> On Sep 4, 2014, at 5:36 AM, Murat Kaipov <mkkaipov at gmail.com> wrote:
>>
>> Hello Guys.
>>
>> I need connect two PoP's with 10G links. Distance between PoP's nearly
>> 120km. We have fiber optic between PoP's with two regeneration points
>> located nearly in 40 km between each other. We have not DWDM. Can you advise
>> some equipment (May be like EDFA) for fiber optic regeneration points
>>
>> Scheme like this
>>
>> PoP-1 ---40km---[Regeneration point1]---40km----[Regeneration
>> point2]-----40km------PoP2
>>
>> Thank you.
>>
>> _______________________________________________
>> cisco-nsp mailing list cisco-nsp at puck.nether.net
>> https://puck.nether.net/mailman/listinfo/cisco-nsp
>> archive at http://puck.nether.net/pipermail/cisco-nsp/
>
>
> _______________________________________________
> cisco-nsp mailing list cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/
>
_______________________________________________
cisco-nsp mailing list cisco-nsp at puck.nether.net
https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/