My guess is that he was talking about the difference between a 100gbit/sec stream of ethernet frames with no error correction, and a 112gbit/sec (or so, depending on scheme) stream of transport with FEC (Forward Error Correction - which is essentially just cramming extra bits in there incase they are needed.

Ethernet has to re-transmit instead, and that can cause performance degradation and jitter, until it just quits working altogether.   Systems implementing FEC are much 

(This is a guess, there’s a chance something else was meant by this)

-LB.

On Sep 25, 2021, at 1:55 AM, Etienne-Victor Depasquale via NANOG <nanog@nanog.org> wrote:

Bear with my ignorance, I'm genuinely surprised at this:

Does this have to be Ethernet? You could look into line gear with coherent optics.

Specifically, do you mean something like: "does this have to be IEEE-standardized all the way down to L1 optics?" Because you can transmit Ethernet frames over line gear with coherent optics, right ?

Please don't flame me, I'm just ignorant and willing to learn.

Cheers,

Etienne

On Fri, Sep 24, 2021 at 11:25 PM Bill Blackford <bblackford@gmail.com> wrote:
Does this have to be Ethernet? You could look into line gear with coherent optics. IIRC, they have built-in chromatic dispersion compensation, and depending on the card, would include amplification.

On Fri, Sep 24, 2021 at 1:40 PM Randy Carpenter <rcarpen@network1.net> wrote:

How is everyone accomplishing 100GbE at farther than 40km distances?

Juniper is saying it can't be done with anything they offer, except for a single CFP-based line card that is EOL.

There are QSFP "ZR" modules from third parties, but I am hesitant to try those without there being an equivalent official part.


The application is an ISP upgrading from Nx10G, where one of their fiber paths is ~35km and the other is ~60km.



thanks,
-Randy


--
Bill Blackford

Logged into reality and abusing my sudo privileges.....


--
Ing. Etienne-Victor Depasquale
Assistant Lecturer
Department of Communications & Computer Engineering
Faculty of Information & Communication Technology
University of Malta