Re: [rrg] Geoff Huston's BGP/DFZ research - 300k DFZ prefixes are the tip of the iceberg

[Paul Jakma <[e-mail]>]

On Mon, 15 Mar 2010, Robin Whittle wrote:

> Also, as just mentioned by Amund Kvalbein:
>
>   BGP churn evolution: A perspective from the core
>
> http://simula.no/research/nd/publications/Simula.nd.435/simula_pdf_file

Yes, saw the post of that. Its conclusion does not disagree with 
Geoff's results, indeed it seems to concur somewhat. (Geoff goes 
further and made the neat observation about possible correlation with 
path-length, I think).

> DFZ.  Cumulatively, these prefixes add up to the single biggest 
> identifiable problem at the heart of the routing scaling problem.

Well, let's look at the flip-side for a moment. Imagine if there were 
/no/ growth in prefixes. Is that good? I think the answer clearly is 
"no". No growth in prefixes implies no growth in the internet, 
implies no growth in revenue for those who make money from activities 
associated with attaching to the net.

I.e. given much of the planet does not have internet access, and 
hence assuming the internet is at least a few decades away from any 
natural slow-down in growth due to saturation (I havn't plugged Brian 
Carpenters 10M prefix figure into Geoff's growth formula, but it 
feels like we've got at least a decade to go):

 	growth in prefixes == good
 	growth in prefixes == healthy internet

So to some extent, (I would say a greater degree) growth in prefixes 
is desirable, at this time.

> This is what we have been doing since the RAWS workshop in 2006, and
> some folks have been researching this since before RAWS.

Well, yes. I know.

I've been discussing scalable and/or IPv6 multihoming with people on 
lists on/off for approaching a decade, perhaps a little more (i'd 
have to go check my mail archives).

> Whoah . . .  You are arguing against the positions of pretty much
> everyone who is involved in the RRG.  Please see 17.2.x of:

Yes. I know. I used to not doubt much there was a scaling problem 
myself (that's what everyone thought and why should i disagree?). 
It's hard to maintain that view though when data starts coming in 
that seems to suggest otherwise. If we're to be scientific about 
this, we have to take heed of data.

> You have asserted there is no routing scaling problem,

Did I?

Could you go perhaps go back to my message where I said how I wished 
to vote. I think you'll find you've misunderstood me.

> but you haven't argued why this is the case - such as by arguing in 
> detail against the arguments presented in the five above documents.

Why do I need to argue the case?

Let the data do the arguing. At the moment it's looking like BGP 
maybe is coping with growth just fine. I.e. we can not yet safely 
conclude there is an urgent scaling problem with internet routing 
(despite path-vector being known now to have some inefficient 
behaviours even when working as intended).

Where's the data suggesting routing is or is going to run into 
problems? Not /fears/ that it will, but actual data.

> The mapping for TTBOMLK was not in my cache.  Google resolved my 
> query in a fraction of a second:

I didn't invent TTBOMLK on the fly and so it's certainly more 
googleable than some acronyms, yes. ;)

>  To The Best Of My Knowledge

The L is "Limited". fwiw ;)

> OK - in the context of the work which has been done so far, I 
> suggest that your assertion that there is no routing scaling 
> problem is just speculation too!

I suspect you've misunderstood my scribblings.

regards,
-- 
Paul Jakma	[e-mail]	Key ID: 64A2FF6A
Fortune:
Chinese saying: "He who speak with forked tongue, not need chopsticks."