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

[Christopher Morrow <[e-mail]>]

On Fri, Mar 12, 2010 at 10:29 PM, Robin Whittle <[e-mail]> wrote:

>  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.

it's not just their own space, it's PA space as well, leaked around
the provider, or through the provider.

>
>  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.)

I reckon most folks don't do it because they haven't hit a reason that
they see to actually do it. If there were a scalable, simple method
for most anything to be 'multihomed' I suspect you'd see a whole lot
more multihoming going on (or mobility, or simple device/network
agility)

> Then there is mobility - which has a prominent place in the RRG
> Charter's description of the routing scaling problem.  Broadly
> speaking, mobility is a whole other iceberg, so far completely submerged.

providers see this in their own networks, but today the technology
doesn't work/exist (no need to debate which) to have this work
reliably and simply across provider boundaries, so it seems
'submerged'.

> 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.

Tony's and VInce's work seems to say that moores law: 1) isn't going
to cut it, 2) doesn't apply anyway... we should just drop this from
the idea bench.

-chris