Gregory's Server
@azonenberg @funkylab @gsuberland @karotte I'd argue the FEC layer in 25GBASE-R is cursed due to all the transcoding and gearboxes to convert 80 64b66b codewords to one 5140b block to append the 140b parity resulting in the same 5280 bits. It's not pretty.
25GBASE-CR-S is nice and pure like 10GBASE-R but the FEC layer is required in everything else 25GBASE-R.
The FEC itself isn't cursed just the wrapper around it.
@dlharmon @azonenberg @funkylab @gsuberland @karotte
Unfortunately people can and do try to run 25G without FEC in the wild (and not short range twinax) . And then there is the firecode vs rsfec question if you do run FEC. The whole history of the 25G consortium, followed by IEEE standardization also adds another layer of cursedness.