Re: constant FEC errors juniper mpc10e 400g

[Mark Tinka <mark@tinka.africa>]

On 4/19/24 08:01, Saku Ytti wrote:

> The frames in FEC are idle frames between actual ethernet frames. So
> you recall right, without FEC, you won't see this idle traffic.
>
> It's very very good, because now you actually know before putting the
> circuit in production, if the circuit works or not.
>
> Lot of people have processes to ping from router-to-router for N time,
> trying to determine circuit correctness before putting traffic on it,
> which looks absolutely childish compared to FEC, both in terms of how
> reliable the presumed outcome is and how long it takes to get to that
> presumed outcome.

FEC is amazing.

At higher data rates (100G and 400G) for long and ultra long haul 
optical networks, SD-FEC (Soft Decision FEC) carries a higher overhead 
penalty compared to HD-FEC (Hard Decision FEC), but the net OSNR gain 
more than compensates for that, and makes it worth it to increase 
transmission distance without compromising throughput.

Mark.