Cost per prefix [was: request for help w/ ATT and terminology]

Patrick W. Gilmore patrick at ianai.net
Sun Jan 20 14:46:22 UTC 2008


On Jan 20, 2008, at 6:06 AM, William Herrin wrote:
> On Jan 19, 2008 11:43 PM, Patrick W. Gilmore <patrick at ianai.net>  
> wrote:
>> On Jan 19, 2008, at 12:55 PM, William Herrin wrote:
>>> There was some related work on ARIN PPML last year. The rough  
>>> numbers
>>> suggested that the attributable economic cost of one IPv4 prefix in
>>> the DFZ (whether PI, PA or TE) was then in the neighborhood of $8000
>>> USD per year.
>>
>> I haven't seen that work, but I am guessing this number is an
>> aggregate (i.e. every cost to everyone on the 'Net combined), not  
>> per-
>> network? See, I'm just looking at that TWO BILLION DOLLARS PER YEAR
>> number and thinking to myself, "um, yeah, right". :)
>
> Patrick,
>
> That was a worldwide total, yes. The cost per prefix per router is
> obviously only measured in cents per year.

I think you mean in tiny fractions of a single cent per router per  
year.  While there are 27K ASes ($0.30/year/AS, remember?), there are  
many more routers which carry a full table.


> You do know that Cisco's sales are north of $20B per year, right?
> Juniper, which sells few products that aren't DFZ routers, also posts
> annual revenues well north of $1B.

Comparing cisco & Juniper's annual revenue to the cost of a prefix is  
like comparing Ford & GM's revenue to the cost of bulbs in  
headlights.  Hell, most of cisco's revenue is not even related to  
routers doing a full table.

Interesting thought experiment.  Let's assume _ALL_ $21B of revenue  
you quote above is routers which can do a full table.  The numbers you  
quote say 10% of that revenue is because of DFZ table size.  I was  
unaware so much cost in a router was just table size.  And since we  
all know that revenue is not all DFZ-capable routers (for instance,  
how much of that $20B is Linksys?), the %-age is much higher.

Wow, router member & CPU must be very expensive - and optics must be  
damned cheap.

Besides the obvious absurdity in this, it contradicts the point I made  
to your last paragraph.

I guess I'm thinking again: "Um, yeah, right". :)


>> Feel free to explain how confused I am.  (But be warned, I am not
>> going to believe it costs $2B/year to run a multi-homed network with
>> two full feeds. :)
>
> The thread started here:
> http://lists.arin.net/pipermail/ppml/2007-September/008927.html
> It was originally an argument of about the cost of doing PI for IPv6,
> which according to Cisco product literature consumes twice the amount
> of space in the FIB as routes for IPv4.

Heaven forbid it costs each ASN an average of TWO DOLLARS per year.   
Eventually, since it will be quite a while before the v6 table is 250K  
prefixes.  Hrmm, I take that back.  By the time there are 250K v6  
prefixes, there will be far, far more ASNs, so the average cost will  
be less.

Anyway, thanks for the link.  I must be missing something seriously  
important to the calculation.  Perhaps it includes things like human  
time to upgrade equipment or filters or something?  I'll see how the  
calculation was put together.

-- 
TTFN,
patrick




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