nanog mailing list archives

Re: 100g PCS Errors


From: Mark Tinka <mark.tinka () seacom com>
Date: Thu, 20 Aug 2020 15:19:05 +0200



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.


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