On Sat, 13 Mar 2010, Robin Whittle wrote:
Geoff's research is:
In the "Re: [rrg] draft-narten-radir-problem-statement-05.txt" thread
http://www.ietf.org/mail-archive/web/rrg/current/msg06152.html
and in "BGP in 2009":
http://www.potaroo.net/presentations/2010-02-01-bgp2009.pdf
Those are the ones. I'd read that email too, but had forgotten of its
existence in replying to this thread - thanks for highlighting it.
It's possible that the current architecture of the internet is
holding back growth that should otherwise be there.
Yes. If we concentrate only on non-mobile networks, there are two
broad aspects of the routing scaling problem:
1 - The unreasonable, arguably unscalable, burden placed on the
DFZ routers individually, and on the DFZ control plane in
general, by the set of end-user networks which currently
get portability, multihoming and inbound TE by the only
means available: getting their own space and advertising it
as PI prefixes in the DFZ.
Well, why is it "unreasonable" exactly? If the system works and is
scalable, what's the problem?
It's only unreasonable if there's a /good/ way to keep those prefixes
out of the DFZ (i.e. good in the sense that it's at least as good as
what we have today). If such a way exists, then that's great - we
should definitely research ways to improve routing, of course.
However, it does not seem justified to say the current routing
architecture has a scaling problem. So it would not be justified, at
thhis time (AFAICT), to excuse inefficiencies added by proposed
changes on the basis that there's a pressing problem with the current
architecture.
2 - The much larger number of end-user networks which could use 2
or more ISPs and which want or need portability, multihoming or
inbound TE but don't have it because they are unable to get the
space and advertise it. (Perhaps a subset of these could do
it, but don't because they known how unscalable it is.)
The growth in BGP advertised PI prefixes is the simplest measure of
the first aspect - which is like the tip of the iceberg. The less
visible part is point 2, like the main body of the iceberg.
Well, the internet is going to grow. That's hardly a surprise. What's
the problem with the internet growing? Geoff's results seem to show
that the growth is well within the scaling abilities of the 'net.
So even if Moore's Law keeps up in some acceptable manner with the
pace of growth in the number of PI prefixes in the DFZ, this
doesn't help with point 2 or with mobility.
Sure, but:
a) If the scope of the problem suddenly is "those very small
networks which want portability/multi-homing but aren't big enough
to get an AS and PI", then:
- it's a much, much smaller problem in terms of affected parties
than "internet routing doesn't scale"
- it's not clear even that such networks exist to any
meaningful extent (OK, I'm geeky enough that I'd love portability
and multihoming for my home network), i.e. if this is the
problem being solved then that changes the economic incentives
of roll-out.
b) If the problem is that fewer networks today can get PI, then we
should be able to see a change in the mode of prefix growth in the
historical data. However, TTBOMLK, we don't see this in the data.
Basically, if there's a problem then where is the evidence of it, now
that we seem to have initial evidence to suggest otherwise?
Sorry I haven't had time to revisit our discussions in early
February. I have a backlog of RRG messages to read and respond to
- mainly discussion following from my critiques of several
architectures - and I need to give priority to paying work.
No worries, that was just speculation on my part anyway. :)
regards,
--
Paul Jakma p...@jakma.org Key ID: 64A2FF6A
Fortune:
If you don't have a nasty obituary you probably didn't matter.
-- Freeman Dyson
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