Tunable QSFP Optics
lists.nanog at monmotha.net
Tue Jun 19 20:43:21 UTC 2018
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.
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