[AusNOG] 10GBase-T SFP modules?

[Lincoln Dale]

hi Skeeve,

On Thu, Jul 10, 2014 at 10:29 AM, Skeeve Stevens <
skeeve+ausnog at eintellegonetworks.com> wrote:

> I know you live in vendor world, but most of us live in the real world.  I
> work in a lot of networks, SP's, Enterprise... old and new.. and I almost
> NEVER come across equipment with 10GBase-T ports in them.  I don't even
> recall the last 10GBase-T port I saw - and this is on a LOT of kit.
>

Love it that you think my world is not a real world or that you think I'm
in marketing. :)
Yes I work for a "vendor" and yes I help design/build/architect ethernet
switches. I'd argue that each of the vendors I've worked for doing this are
'successful' as measured by real-world tangible metrics of "revenue",
"market share."
Its not possible for me to make any of this up, its a matter of public
record in compliance with publicly filed documents.

Maybe that you haven't ever seen 10GBASE-T is a reflection of either what
you recommend to your customers, or vendors you work with or their choice
of compute or storage.
Certainly 10GBASE-T is a challenge on things like blade servers. A lot of
my experience and what I see comes from what some of the world's largest
cloud and web2.0s are doing.


>
> This very much sounds like the property people saying 'The market is going
> to increase and values increasing!' just to justify and push up their own
> sales.
>

I've pointed you at some public research but feel free to look further if
you want. Market research data from Cehan, Infonetics, Dell'oro and IDC
will all show this - both backwards-looking actual and forward-looking
estimates.

The big advantage 10GBASE-T has is that for most people with 10/100/1000
attached devices today, they can upgrade infrastructure for some devices
being 10G attached while still catering for existing 1G attached devices.
(of course, you could achieve that with SFP+ based switch ports that are
capable of taking a 1000BASE-T SFP in them too, but its not going to be at
the same price point.)


>
> Don't misunderstand me... I think 10GBase-T is awesome and I recommend
> people consider it as a TOR over SFP+ anytime they have a number of ports
> to justify it... but few do due to the lack of portability of 10GBase-T -
> meaning you need those ports wherever kit is moved to, very few people are
> seriously considering it as a choice to deploy.
>

No idea what you mean by "lack of portability."  Maybe that its electrical
and not optical so is restricted distance of 100m?
Generally speaking, 100m distance is fine within a data center for all but
the largest cloud/web2.0's who have mega-scale type problems of doing cost
effective high performance networking where distances exceed 100m.

Sure - for a service provider or doing a cross-connect you'd always do that
optically with SMF. But since the original poster here was talking about
server connectivity I'm answering on the basis this is about server/storage
connectivity inside a data centre.


>
> With cost, I am not talking about the SME crap... it is a hell of a lot
> cheaper to deploy 10GBase-T switches - the switches are a bit more
> expensive, but once you factor in SFP+ modules into a switch, the opticals
> are much more expensive.
>

I'm making an apples/apples comparison of cost of 10G passive DAC SFP+
(10GBASE-CR) to 10GBASE-T.
Latter is most cost effective.



>
> I also meant to the vendor who replied about the 10GBase-T <-->SFP+ module
> possibility... and that making that, which would be consumed in VERY low
> numbers (my opinion) that the business case would be hard - for anything -
> made where the numbers shipping would be low.
>

The point is moot, because from an engineering perspective, even using
not-quite-yet-productized 22nm 10G-T PHYs, they don't fit in either
power/heat envelope for a SFP+ (1.5W maximum) nor would physically fit
inside it (die size too large.)

To give an example (this is a 40nm part), <
http://www.broadcom.com/collateral/pb/84833-PB02-R.pdf> shows that the PHY
itself is in a 25mm package and you still need the transformer/magjack
piece before the RJ45.
Its simply not physically possible to put all those in a SFP+ package today.



> Re switch availability...
>

There is far out there from the vendors you list.
(of course they aren't going to have it in "low end" 1G switches that you
list. They're "low end" and "entry level price" for a reason..)



cheers,

lincoln.
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