Re: provider-int geo aggr [Re: plug: thesis on site multihoming]

[Pekka Savola <pekkas@netcore.fi>]

On Sun, 30 Mar 2003, Iljitsch van Beijnum wrote:
> > A,B,C,D are part of one AS.  If you try to expand that so that they
> > aren't, you get into trouble.
> 
> And that's exactly the point: we aggregate inside provider networks.
> 
> > In the same way, if you don't expand it,
> > you are just solving the provider-internal problem -- and are requiring
> > the propagation of more specifics in DFZ.
> 
> Yes. But since no single router has to keep a copy of the entire DFZ 
> routing table, this is no longer a problem.

Ok -- now I think I understand the concept.

If the max number of routes a router implementation can handle is N and
more-or-less-complete routing table (non-existant but as a concept) would
be Y (>N), you require that each ISP would have at least Y/N (rounded up)
routers each connected separately to the Internet -- that, between
operators you'd have at least Y/N (rounded up) interconnections if you
wish to have optimal paths, etc.

Forgive me saying this, but this kind of model which requires a lack of
aggregates in the core, and sets requirements for ISPs' border routers
just doesn't seem to fly.

My argument as an operator is that unless you can divide & conquer the the
full routing table to such proportions that it can't be uniform in one AS,
there's something very broken in the design of the internet routing
architecture, or the definition of the AS.

Certainly, the basic concepts of how these different routers with partial
knowledge interact with peers' and upstreams' routers of partial knowledge
seems quite fuzzy .. and this is one thing that seems critical to have
clarified (some pictures might be illustrative).

But as this seems a different proposal than Tony's, I'll remove the
reference.
 
> It all boils down to the question: why would someone in Europe need 
> more specifics for people in the US, or vice versa?

Depends on the level of interconnection and how the routes are set up, 
there.

Currently, there is no abstraction, so it's difficult to estimate..  But
if there was, people would probably very much like *their* pretty little
route going through optimal paths and being in the full routing table of
all the routers.

I haven't really been able to form a picture in my head how the proposal
would have to be practically enabled for example through a path from an
European ISP to U.S. ISP, in between having or maybe not having transits
and ISP's which may or may not honor this model.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings