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Does anyone know what's the difference between LR1 and LR4 optics?

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  • Removed the off-topic request for resources.
    – Ron Maupin
    Feb 11 '21 at 19:24
  • Did any answer help you? if so, you should accept the answer so that the question does not keep popping up forever, looking for an answer. Alternatively, you could post and accept your own answer.
    – Ron Maupin
    Dec 23 '21 at 16:35
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As in 10GBASE-LR versus 40GBASE-LR4?

-L stands for long ~1300 nm wavelength (as opposed to -S for 850 nm and -E for ~1550 nm). -R stands for large block code 64b/66b.

The suffix 4 stands for the number of lanes. With -L, those lanes are multiple wavelengths (CWDM) that are merged by the sender and split again by the receiver. Accordingly, 40GBASE-X requires a QSFP+ optical module with four (Q) 10 Gbit/s (SFP+) lanes. 10GBASE-X uses a narrower, single-lane SFP+ module.

There are other module form factors than (Q)SFP(+) but those are the ones most widely used. The lane scheme applies to all of them since it is required by the PHY standards.

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