Re: Tunable QSFP Optics

[Brandon Martin <lists.nanog () monmotha net>]

On 06/19/2018 04:16 PM, Luke Guillory wrote:
> Seeing that it seems I’m misunderstanding things, so I went grab a meter and checked what was leaving. Both of the 
> 100g SFPs were only outputting on 1310, while the 40g showed each of the 4 lanes.

IIRC, the lambda spacing for 100GBASE-LR4 is tighter than 40GBASE-LR4.  40G is spaced on the normal 20nm CWDM grid.  
100G is spaced tighter at just under 5nm so that the entire thing mostly fits within the 20nm-wide "1310nm" CWDM grid.  
If you're using a CWDM meter, it'll probably bin it exactly that way.

There's a separate non-IEEE "100GBASE-CWDM4" that has the 20nm lambda spacing like 40G does.
-- 
Brandon Martin