100g PCS Errors

Thu Aug 20 13:19:05 UTC 2020

On 20/Aug/20 08:16, Saku Ytti wrote:

> On QSFP28 devices I would recommend always when possible run RS-FEC.
> By default LR4 doesn't run it, but the added value is fantastic. You
> will immediately during turn-up know if circuit works or not, without
> any ping testing or live traffic. You will know if the circuit doesn't
> work, before it impacts customers. Combine preFEC with DDM and you
> have fantastic predictive power over failures and you can
> reroute/schedule maintenance to fix issues before they become
> symptomatic.

Yes, thanks. I recall you recommended this to someone earlier in the
year, so we have it in our library for deployment when we do the turn-up.

All our 100Gbps deployments are currently within the data centre, so SR4
optics; which Juniper enables RS-FEC on by default. But yes, we shall
definitely do the same (manually) for LR4.

IOS XR appears to suggest that FEC configuration is not explicitly
needed, unless the optic is a non-Cisco qualified non-LR4 unit.

Mark.