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

Ben Butler ben.butler at c2internet.net
Sun Jan 20 16:22:31 UTC 2008


Hi Patrick,

I agree, if anything I am advocating a spanking of those in the clueless
category, thus reducing the table size so that up to 110K more PI space
and corporate multi homing can occur without increasing the table
further than today.  Seems like a quick gain in flexibility and
functionality for the corporate customers while curtailing the littering
of those that should know better.

Of course it begs the question when do we run out of AS numbers / PI
space - maybe one of those events would now actually happen before
routers collapses under the weight of route table from corporate
multihoming once we have tided up the unnecessary PA deag.

Or maybe... we will run out of corporates first!  Which would have to be
the best of outcomes, everyone multihomed how wants/needs plus a
manageable route table without having run out of IPs or AS numbers.  Or
am I just living in fairy land?

I guess without knowing the size of the wave of corporate foaming out
the mouth to multihome it is difficult to know whether pushing back the
flood of deagregated PA by 110K is enough to make a serious dent in the
corporate wave or just a ripple to a problem that is too big to ever
solve and enormous route table are inevitable and 100K extra routes from
PA is neither here nor there at the end of the day?????

Has anyone worked out any numbers / projections on this going forwards
into the future?

Ben

-----Original Message-----
From: owner-nanog at merit.edu [mailto:owner-nanog at merit.edu] On Behalf Of
Patrick W. Gilmore
Sent: 20 January 2008 15:12
To: nanog at merit.edu
Cc: Patrick W. Gilmore
Subject: Re: Cost per prefix [was: request for help w/ ATT and
terminology]


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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