LX sfp minimum range

Wayne E Bouchard web at typo.org
Thu Jan 26 23:19:38 UTC 2012

On Thu, Jan 26, 2012 at 10:48:05PM +0000, Gary Buhrmaster wrote:
> On Thu, Jan 26, 2012 at 13:47, David Storandt <dstorandt at teljet.com> wrote:
> > You can put a 3dB or 5dB optical pad on the link if the receiver can't
> > handle zero-distance optical power.
> As I recall, the problem may not only be the power
> (which can cause receiver saturation), but issue that
> fibre paths shorter than (around) 2-10m do not properly
> condition the light(*), which can result in some issues
> at the receiver.
> Gary
> (*) My memory says modal distribution issues.
>     While 'single mode' fibre only supports one
>     mode of transmission, it takes a short distance
>     for the fibre to really be single mode.  You can
>     use a mode filter to address the problem, or just
>     use fibres that are at least a few meters.

When optics started to become scarce at various times, I've done a
number of back-to-back connections using SM fiber and have had zero
issues. I wouldn't even worry about it. Remember, many carriers won't
even touch MM and they aren't chronically reporting issues or going to
lengths to work around them.


Wayne Bouchard
web at typo.org
Network Dude

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