nanog mailing list archives

Re: Is there such a thing as a 10GBase-T SFP+ transciever


From: Eric Clark <cabenth () gmail com>
Date: Fri, 31 Jan 2014 04:39:48 -0800

What I want to see is reasonably priced 40G single mode transceivers.

I have no idea why 40G and now 100G wasn't rolled out with single mode as the preference. The argument that "there's a 
large multimode install base" doesn't hold water.

For one thing, you're using enormous amounts of MM fiber to get at best 1/4 of the ports than you previously had.
The best case is that you could get 12 ports where you used to have 48, but that's messy.
The second issue is cost, if you're running and distance, you've got to go to OM4, because MM fiber has very limited 
range at 10G (you're multiplexing 10G links), and OM4 is insanely expensive.

Single Mode on the other hand is 'cheap' in comparison. One pair of SM fiber will handle every speed from 10M to 100G, 
and over much longer distances than MM, no matter what grade.

Unfortunately, since the manufacturers haven't seen fit to push the SM, the optics are extremely expensive, so we're 
stuck with 4-12 times the amount of installed fiber than we really need.

Grumble.


On Jan 30, 2014, at 6:25 PM, Chris Balmain <chris () team dcsi net au> wrote:

You may wish to consider twinax for short distance 10G over copper with SFP+ at both ends

http://en.wikipedia.org/wiki/Twinaxial_cabling#SFP.2B_Direct-Attach_Copper_.2810GSFP.2BCu.29

Typically marketed as "direct-attach" (you can't remove the cables from the transceivers, it's all integrated)

On 31/01/14 12:26, james jones wrote:
I would like to know if anyone has seen one of these? If so where? Also if
they don't exist why? It would seem to me that it would make it a lot
easier to play mix and match with fiber in the DC if they did. Would be so
hard to make the 1G SFPs faster (trying to be funny here not arrogant).


-James




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