Address clustering intuition

Geert Jan de Groot GeertJan.deGroot at
Thu Nov 9 23:40:40 UTC 1995

On Thu, 09 Nov 1995 16:17:30 -0700  "Walter O. Haas" wrote:
> >No, this does not work. Looking at Europe, I know of several ISPs
> >to which the shortest path from here (Amsterdam, the Netherlands)
> >is via MAE-EAST; they either don't have external connectivity
> >on the continent itself, or we have no provider willing to provide
> >transit between here and their continental connectivity.
> It would seem that given a free market these providers would find it
> cheaper to connect locally than make two hops across the Atlantic.  Even
> if a few go the long way, I would think cost considerations would keep
> the number of such providers down, and limit them to the East Coast of
> the US.  This would accomplish the same effect of limiting the number
> of routers that would need to know this detail

It does not work that way; tariffs are weird beasts.
I can't be very specific without naming names which I do not 
want to do without permission.

Realize that an ISP can be 'in business' if they hook up via
an US ISP; local connectivity is 'extra cost' the advantage of
which only becomes clear with reasonable traffic levels.

> >There is a second, similar reason: assume that A and B each operate
> >in the same area. They use different carriers for transit to MAE-EAST.
> >Who of these is going to announce the aggregated announcement?
> >If A does it, it pays for the transit for customers of B.
> >If they both announce it, then they still pay for eachother's
> >traffic.
> Presumably MAE-EAST would know enough detail about who was connected to
> A and B to make the right decision on transit carrier.  If A and B were
> far enough away from MAE-EAST then they would probably find it more
> economic to make an interchange locally.

The mae-east boxes are the ones most in danger right now, so
your suggestion does not help as they would need to know this
amount of detail (read: no aggregation), and thus still need
to carry the routes we want to get rid of via Europe.

Said otherwise: if you would hear different parts of 'europe'
via UUnet, EUnet, Pipex, PSI and others, would you still know
how to aggregate these for use at MAE-EAST?

Walter, I do not want to offend you, but this has been hashed out 
several times already. You may want to scan the archives of cidrd, 
nanog and other lists.

Geert Jan

PS: asp: I don't have records of the big-I discussion you refer to.
If it can be easily summarized, then that would make a good start
in making the FAQ happen.

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