Re: constant FEC errors juniper mpc10e 400g

[Mark Tinka <mark@tinka.africa>]

On 4/19/24 10:08, Saku Ytti wrote:

> Of course there are limits to this, as FEC is hop-by-hop, so in
> long-haul you'll know about circuit quality to the transponder, not
> end-to-end. Unlike in wan-phy, OTN where you know both.
>
> Technically optical transport could induce FEC errors, if there are
> FEC errors on any hop, so consumers of optical networks need not have
> access to optical networks to know if it's end-to-end clean.

This would only matter on ultra long haul optical spans where the signal 
would need to be regenerated, where - among many other values - FEC 
would need to be decoded, corrected and re-applied.

SD-FEC already allows for a significant improvement in optical reach for 
a given modulation. This negates the need for early regeneration, 
assuming other optical penalties and impairments are satisfactorily 
compensated for.

Of course, what a market defines as long haul or ultra long haul may 
vary; add to that the variability of regeneration spacing in such 
scenarios being quite wide, on the order of 600km - 1,000km. Much of 
this will come down to fibre, ROADM and coherent pluggable quality.

Mark.