nanog mailing list archives

RE: 100G DWDM FEC standard


From: Peter Lothberg <roll () Stupi SE>
Date: Tue, 9 Jun 2015 16:46:45 CEST

From a standards perspective keep in mind that
http://www.stupi.se/Standards/100G-long-haul4.pdf is not approved -
but we are working hard on it. OTOH having a reference
implementation at hand, is an accelerator that helps a lot.

There is a whole industry that do not want it to be plug and play...  

(The ones that do not make routers or switches..)

Let me also add some color to your email as the current
interoperability situation in WDM is quite funny. Sometimes
transceivers of the same vendor can't talk to each other, as they
are based on a different generation of ASICs and therefore FEC
implementations. In other words, vendors typically have more than
only one secret sauce they cook with, and different sauces do not
blend well :-) .  Perhaps transport folks are already too used to
deal with such kind of issues that no one laments anymore. On the
other hand perhaps, the networking industry is already so used to
Ethernet where interopera bility is a no-brainer, that it is
difficult to imagine what it means to deal with a technology that
prevents multi-vendor interop. 

All vendors have secret souce for 100G SD-FEC, and just the fact that
you can wire the wire the differential encoding eight ways..

That;s why we settled on a HD-FEC that can be inside the DSP-Asic or
inline after it. All to us known DSP implementations supports this
with more, less or no extra logic. And the logic is free and fully
documented. 

To confirm your final point:
Interoperability is on the top of the shopping lists for the
networking industry.

Amen!


-P


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