60 ms cross-continent

Saku Ytti saku at ytti.fi
Sun Jun 21 06:08:06 UTC 2020


On Sat, 20 Jun 2020 at 23:14, Bryan Fields <Bryan at bryanfields.net> wrote:

> I think he might be referring to the newer modulation types (QAM) on long haul
> transport.  There's quite a bit of time in uS that the encoding takes into QAM
> and adding FEC.  You typically won't see this at the plug-able level between
> switches and stuff.

FEC is low tens of meters (i.e. low tens of nanoseconds), QAM is less.
Won't impact the pipeline or NPU scenarios meaningfully, will impact
the low latency scenario.

-- 
  ++ytti


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