[c-nsp] Third party optics

[Saku Ytti]

On Thu, 21 Oct 2021 at 09:22, <garry at mlfwd.de> wrote:

> Risk? Not really any risk there ... in 20+ years of using third party
> optics/SFPs, we've never had an issue with any ... only situation, as
> others have stated, could be when opening a ticket with TAC and the
> optics aren't reported as Cisco ...

When optic MSA is young (100G still kind of qualifies, 400G
definitely) there are a lot of interop issues, as different parties
interpret MSA ambiguities differently. Copper link-down detection is a
notorious source of issues as well. So certainly the 1st party has a
higher probability of not having interop problems. Over time the
market converges to specific interpretation of MSA and the probability
of parts working together becomes so high you can't justify testing.

Having said that, the only way to actually know what you are buying is
to buy from a 3rd party. Vendor changes the optic without changing
SKU, so if you're doing any type of testing, it's largely belief work
with low utility, as you won't know if the next order is the same
parts or not. It is possible to source from 3rd party in a way where
you know what parts are used and they can guarantee to ship those
parts or notify of changes.

So if you are willing to test and occasionally work with your 3rd
party provider to solve interop issues, I think 3rd party is much more
preferable. If you just want to call a single number and say 'make it
go' and never test, 1st party is better.

The range of ways to source from 3rd parties is large, there are
brokers who ship whatever they can find, there are resellers who
regularly change suppliers, there are resellers who always source from
X if they have the part and then you can buy directly from the
manufacturer. So there is much more room to do 3rd party sourcing
wrong compared to 1st party sourcing. But if you are able to do it
right, it tends to be the superior way to do it.

-- 
  ++ytti