nanog mailing list archives
Re: dark fiber and sfp distance limitations
From: Mikael Abrahamsson <swmike () swm pp se>
Date: Sun, 3 Jan 2010 00:19:04 +0100 (CET)
On Sat, 2 Jan 2010, Justin M. Streiner wrote:
Some OTDRs (or, more correctly, fiber test sets that include OTDR capabilities) are multi-function devices that will show you the overall length (assuming the span is not broken somewhere in the middle), of the span, plus attenuation and reflections (spikes) at your desired wavelength in one complete package.
Well, that I can understand, what I can't understand is why someone would *ONLY* do OTDR. Attenuation testing end-to-end (as opposed to classic OTDR that do the testing from single end) is needed for accurate measurements, and if it shows something strange, then it's warranted to break out the OTDR. If your equipment can do both in one go, fine.
I'm a big believer in running my own tests when possible, and not just relying on $provider's word. It also allows me to verify what their engineering reports tell me about the condition of a span.
I guess it's all a matter of how much effort you want to put into provisioning. Personally I'm happy enough if the DOM readings (indicating attenuation) on the optics seem reasonable considering the distance of the fiber. If they seem strange, then yes, by all means, break out the testing kit.
-- Mikael Abrahamsson email: swmike () swm pp se
Current thread:
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- Re: EDNS (Re: Are the Servers of Spamhaus.rg and blackholes.us down?) bmanning (Jan 01)
- Re: EDNS (Re: Are the Servers of Spamhaus.rg and blackholes.us down?) Paul Vixie (Jan 01)
- Re: EDNS (Re: Are the Servers of Spamhaus.rg and blackholes.us down?) Eric Brunner-Williams (Jan 01)
- dark fiber and sfp distance limitations Mike (Jan 01)
- Re: dark fiber and sfp distance limitations Justin M. Streiner (Jan 01)
- Re: dark fiber and sfp distance limitations Mikael Abrahamsson (Jan 02)
- Re: dark fiber and sfp distance limitations Michael K. Smith (Jan 02)
- Re: dark fiber and sfp distance limitations Justin M. Streiner (Jan 02)
- Re: dark fiber and sfp distance limitations Nick Hilliard (Jan 02)
- Re: dark fiber and sfp distance limitations Mikael Abrahamsson (Jan 02)
- dark fiber and sfp distance limitations Mike (Jan 01)
- Re: EDNS (Re: Are the Servers of Spamhaus.rg and blackholes.us down?) bmanning (Jan 01)
- Re: dark fiber and sfp distance limitations Richard A Steenbergen (Jan 01)
- Re: dark fiber and sfp distance limitations Alexander Harrowell (Jan 01)
- Re: dark fiber and sfp distance limitations ML (Jan 01)
- Re: dark fiber and sfp distance limitations William Herrin (Jan 01)
- Re: dark fiber and sfp distance limitations Rene Avi (Jan 02)
- Re: dark fiber and sfp distance limitations Richard A Steenbergen (Jan 02)
- Re: dark fiber and sfp distance limitations Rene Avi (Jan 02)
- RE: dark fiber and sfp distance limitations John van Oppen (Jan 06)
- Re: dark fiber and sfp distance limitations Nick Hilliard (Jan 01)
- RE: dark fiber and sfp distance limitations Frank Bulk - iName.com (Jan 04)