Shim6, was: Re: filtering /48 is going to be necessary

Tue Mar 13 23:35:24 UTC 2012

In a message written on Wed, Mar 14, 2012 at 07:58:30AM +0900, Randy Bush wrote:
> none of which seem to move us forward.  i guess the lesson is that, as
> long as we are well below moore, we just keep going down the slippery,
> and damned expensive, slope.

Bill's model for price is too simple, and it's because the number
of devices with a full table change as the price pressure changes,
and that causes other costs.  Quite simply, if a box that could
take a full table were 10x cheaper, more people would take a full
table at the edge.  More full tables at the edge probably means
more BGP speakers.  More BGP speakers means more churn, and churn
means the core device needs more CPU.

TL;DR A savings in ram may result in an increased need for CPU, based on
a change in user behavior.

I also think the difference in the BOM to a router vendor is small
for most boxes.  That is the actual cost to manufacture difference
between a 1M route box and 2M route box is noise, on the high end
the cost of 40 and 100G optics dominate, and on the low end in a
CPU switching box RAM is super-cheap.

The only "proof" I can offer is the _lack_ of vendors offering
different route-holding profiles, and that the few that do are stuck
in the mid-range equipment.  If the route memory was such a big
factor you would see more vendors with route memory options.  Indeed,
over time, the number of boxes with route-memory options have dropped
over time and I think this is due to the fact that memory prices
have dropped _much_ faster than CPU or optic prices.

TL;DR backbone routers are on a treadmill for faster interfaces, and
memory is a small fraction of their cost, edge routers are on a tredmill
for more CPU for edge features, and again RAM is a fraction of their
cost.  It's only boxes in the middle being squeezed.

I'll note Bill used the 6509/7600 platform, which is solidly in the
middle and does have route-memory options (Sup720-3C Sup720-3CXL).
If my theory is right, he used pretty much the _worst_ case to
arrive at his $8k per route figure.  The list price difference in
these two cards is $12,000 to go from 256,000 routes to 1,000,000
routes.  $12,000 / 750,000 routes = 1.6 cents per route per box.

That matches Bill's number (and I think is where he got it), $8000
route/box / 1.6 cents/route/box = 500,000 boxes.

But that box has a 5-7 year time frame, so it's really more like
(being generous) $1600 per route per box per year.

Priced a 100 Gig optic lately, or long haul DWDM system?  I don't think
the cost of routes is "damned expensive".

-- 
       Leo Bicknell - bicknell at ufp.org - CCIE 3440
        PGP keys at http://www.ufp.org/~bicknell/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 826 bytes
Desc: not available
URL: <http://mailman.nanog.org/pipermail/nanog/attachments/20120313/c02f046e/attachment.sig>