Re: 100GbE beyond 40km

[Lady Benjamin Cannon <lb () 6by7 net>]

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 <mailto: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 <mailto: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
> Web. https://www.um.edu.mt/profile/etiennedepasquale <https://www.um.edu.mt/profile/etiennedepasquale>