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

Patrick W. Gilmore patrick at ianai.net
Sun Jan 20 15:12:12 UTC 2008


Ben,

I believe you are correct that PA deaggregation is a huge problem, but  
some of that could be corporate multi-homing.  (I don't know for  
certain whether it is greater or less than providers just being  
ninnies.)  Lots of companies get a /24 from one upstream and announce  
it to two or more upstreams.  That is, IMHO, a legitimate  
deaggregation, as opposed to a provider who is just too clueless  
aggregate.


But before we go too far down this road, everyone here should realize  
that new PI space and PA deaggregation WILL CONTINUE TO HAPPEN.

Many corporations paying for Internet access will NOT be tied to a  
single provider.  Period.  Trying to tell them "you are too small, you  
should only let us big networks have our own space" is a silly  
argument which won't fly.

The Internet is a business tool.  Trying to make that tool less  
flexible, trying to tie the fate of a customer to the fate of a single  
provider, or trying force them to jump through more hoops than you  
have to jump through for the same redundancy / reliability is simply  
not realistic.  And telling them it will cost some random network in  
some random other place a dollar a year for their additional  
flexibility / reliability / performance is not going to convince them  
not to do it.

The number of these coAt least not while the Internet is still driven  
by commercial realities.  (Which I personally think is a Very Good  
Thing - much better than the alternative.)  Someone will take the  
customer's check, so the prefix will be in the table.  And since you  
want to take your customers' checks to provide access to that ISP's  
customer, you will have to carry the prefix.


Of course, that doesn't mean we shouldn't be thrifty with table  
space.  We just have to stop thinking that only the largest providers  
should be allowed to add a prefix to the table.  At least if we are  
going to continue making money on the Internet.

-- 
TTFN,
patrick



On Jan 20, 2008, at 7:08 AM, Ben Butler wrote:

>
> Hi,
>
> Out of curiosity was the reasoning also to charge the PA who are
> deagregating?
>
> To restate there are 113,220 extra routes smaller than RIR minimums  
> out
> of the /24:126,450 in the table.  The today reality seems to be that
> 113K of that 126K is probably being caused by existing networks
> de-aggregating PA.
>
> While I would I would agree that corporate multihoming with PI has a
> huge potential problem on the table in terms of number of prefixes.
> Further more as BGP skills are becoming more common place and
> Linux/Quagga skills the barrier to entry for a corporate is reducing  
> at
> the same time their commercial reliance on and use of the Internet is
> increasing.
>
> Corporate multihoming - if permitted - has the inevitable  
> consequence of
> an extra prefix.
>
> PA deagreagtion - has the avoidable consequence of lots of extra
> prefixes.
>
> I know who I would be charging first and maybe it would give the much
> need incentive for them to clean house.  We could then have some  
> number
> up to 113K new multihomed corporate before we got back to where we are
> today in terms of route table size.  An interesting question to gauge
> the size of the corporate multihoming potential problem is to guess  
> how
> many there may be worldwide that would bother / try - I have no idea.
>
> I believe (possibly wrongly) that IPv6 doesn't really have a solution
> for multihoming corporate with multiple allocations and weird shims  
> and
> NAT configurations to get it to work - or have the RIRs decided on a
> policy change yet and issuing PI blocks of IPv6 as well?
>
> Am I correct on my interpretation of the numbers for PA:PI smaller
> prefix origins?
>
> Kind Regards
>
> Ben
>
> -----Original Message-----
> From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf  
> Of
> William Herrin
> Sent: 20 January 2008 11:06
> To: Patrick W. Gilmore
> Cc: nanog at merit.edu
> Subject: Re: Cost per prefix [was: request for help w/ ATT and
> terminology]
>
>
> 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.
>
> 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.
>
>
>> 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.
>
> I encourage you to critique the numbers and then add them up for
> yourself.
>
> Regards,
> Bill Herrin
>
>
> -- 
> William D. Herrin                  herrin at dirtside.com  bill at herrin.us
> 3005 Crane Dr.                        Web: <http://bill.herrin.us/>
> Falls Church, VA 22042-3004
>




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