nanog mailing list archives

Re: Router Suggestions


From: Owen DeLong <owen () delong com>
Date: Wed, 17 Jun 2020 19:00:43 -0700



On Jun 17, 2020, at 12:50 AM, Mark Tinka <mark.tinka () seacom mu> wrote:



On 16/Jun/20 23:26, Owen DeLong wrote:

Count your blessings…

I know that we are lucky that in the markets we operate, local depots
are available. There are other markets in Africa that may not be so
lucky. If we ever built into those markets, we'd certainly cold spare as
much as possible, as we used to in the current markets that the vendors
didn't have local depots for 10 or so years ago.


As I said, YMMV, but I’m betting your vendor doesn’t stock a second copy of every piece of covered equipment in the 
local depot. They’re playing the statistical probabilities just
like anyone else stocking their own spares pool. The biggest difference is that they’re
spreading the risk across a (potentially) much wider sample size which may better normalize
the numbers.

Yes, it's just like a bank - they hope not all customers come to
withdraw all their cash on the same morning.

Yep… FWIW, my experiences were in locations in the US with NFL teams and multiple depots proximate to each location. 
That didn’t help in these cases.

We run a CRS 4-port 100Gbps line card that I know is not very popular
among other operators in the markets where we have them. We had one fail
in a smaller city a few weeks ago. We pay for NBD, not 24/7. A new line
card arrived promptly, the morning after. I did hold my breath, but they
managed.

Yeah, that’s far less likely to be a problem than a popular line card or other component that turns out to have a bad 
batch. Generally, they’ll keep at least one of everything any customer has in at least one nearby depot. OTOH, I bet if 
you’d had two of those cards fail, you might
have been SOL on the second one for a couple of days.

Owen



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