nanog mailing list archives
Re: dark fiber and sfp distance limitations
From: Alexander Harrowell <a.harrowell () gmail com>
Date: Sat, 2 Jan 2010 00:23:09 +0000
On Friday 01 January 2010 23:19:30 Richard A Steenbergen wrote:
On Fri, Jan 01, 2010 at 02:52:33PM -0800, Mike wrote:I am looking at the possibility of leasing a ~70 mile run of fiber. I don't have access to any mid point section for regeneration purposes, and so I am wondering what the chances that a 120km rated SFP would be able to light the path and provide stable connectivity. There are a lot of unknowns including # of splices, condition of the cable, or the actual dispersion index or other properties (until we actually get closer to leasing it). Its spare telco fibers in the same cable binder they are using interoffice transport, but there are regen huts along the way so it works for them but may not for us, and 'finding out' is potentially expensive. How would someone experienced go about determining the feasibillity of this concept and what options might there be? Replies online or off would be appreciated.That shouldn't be too difficult, especially at only 1G (though pesonally I can't imagine why you would bother leasing dark fiber for that :P). There are several ways you could do it, including 120km+ rated SFPs (iirc there have been 200km SFPs out for a while too), an external optical amplifier (ideally you'd want to amp in the middle, but with a single channel you should be fine w/pre-amp), and a digital FEC wrapper to extend the receive sensitivity. Remember that the distance spec on optics is mostly a rough guideline, so depending on the fiber conditions and number of splices/panels along the way you could potentially expect to get the entire distance out of a "standard" 100km optic.
There was an excellent thread on this list last year about using "unusual" high power lasers for long range optical networking. http://www.merit.edu/mail.archives/nanog/2008-10/msg00226.html
Attachment:
signature.asc
Description: This is a digitally signed message part.
Current thread:
- Re: EDNS (Re: Are the Servers of Spamhaus.rg and blackholes.us down?), (continued)
- 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: 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)
- Re: dark fiber and sfp distance limitations Kevin Hodle (Jan 02)
- RE: dark fiber and sfp distance limitations Martin, Paul (Jan 04)