nanog mailing list archives
Re: DWDM and EDFA and DCM
From: Evelio Vila <evelio () thousandeyes com>
Date: Wed, 22 Apr 2015 15:01:46 -0700
I think the OP is asking about whether it should account for chromatic dispersion or not. Intramodal dispersion may very well be a limit on your link even the power budget (as presented before) is fine. As Mikael said, I would stick to the specs from the manufacturer for that specific module, or rent an OTDR and make the measurements. -- Evelio On Wed, Apr 22, 2015 at 1:51 PM, Baldur Norddahl <baldur.norddahl () gmail com> wrote:
First: buy a power meter. They are really cheap and the only way to know for sure how much signal you got. It will also tell you how much launch power you have. The fiberstore modules are listed as 0 to +5 dBm launch power - if you got lucky it might be +5 and if you got a lower end module it might be close to 0. Obviously this makes a huge difference for how much power you get on the other end. Also it is said that the laser will lose power over time. Second you need to think in terms of power budget, not distance. So you got 68 km and the module is rated for 80 km - but not all fiber is not born equal. A power meter allows you to measure the true link loss. Third you did not tell what DWDM multiplexer you are using. A 44 channel DWDM multiplexer from Fiberstore can have up to 4.5 dB insertion loss. You might have two of those on your link for a total of 9 dB loss. Your 80 km module has a 23 dB link budget, so this leaves you with 23-9 = 14 dB budget. If your fiber has 0.25 dB loss per km, that is only 56 km. Regards, Baldur
Current thread:
- DWDM and EDFA and DCM Rodrigo Augusto (Apr 22)
- Re: DWDM and EDFA and DCM Mikael Abrahamsson (Apr 22)
- Re: DWDM and EDFA and DCM Rodrigo Augusto (Apr 22)
- Re: DWDM and EDFA and DCM Baldur Norddahl (Apr 22)
- Re: DWDM and EDFA and DCM Evelio Vila (Apr 22)
- Re: DWDM and EDFA and DCM Rodrigo 1telecom (Apr 22)
- Re: DWDM and EDFA and DCM Shawn L (Apr 22)
- Re: DWDM and EDFA and DCM Rodrigo Augusto (Apr 22)
- Re: DWDM and EDFA and DCM Mikael Abrahamsson (Apr 22)
- Re: DWDM and EDFA and DCM Mikael Abrahamsson (Apr 22)
- Re: DWDM and EDFA and DCM Brandon Martin (Apr 23)
- RE: DWDM and EDFA and DCM Jameson, Daniel (Apr 23)