RE: [RRG] Geographic aggregation-based routing is at odds with reality

["Tony Li" <tony.li@tony.li>]

|This is my opinion, of course.  I am stating it as if it is a fact
|because I am sure it is true.  


Good to see that you're keeping an open mind.  ;-)


|I am frustrated at the way
|geo-aggregation keeps emerging in this discussion, which I believe
|should concern proposals which have the potential to be compatible
|with business, security and policy reality.


Well, unfortunately, we don't all live in my reality.  ;-)

Over in my reality, geo-aggregation has some substantial benefits (and
drawbacks).  The real key with geo-aggregation is the scope that the
aggregation happens on and the strictness with which the rules are applied.

The scope of geo-aggregation can vary widely.  One could, in extreme cases,
have geo-aggregation down to the city block level.  At the opposite extreme,
one could have continental aggregation.  [If one exists in Vint Cerf's
reality, one might even argue for planetary aggregation.  ;-)]

Similarly, one can be very relaxed with the aggregation rules, simply
distributing an aggregate at some boundary and filtering internal more
specifics and allowing more specifics to be originated outside of the
abstraction naming boundary.  Or, one can be draconian and insist that there
be no exceptions to the aggregate.

If we take for example a continental aggregation with relaxed rule keeping,
you can see that prefixes within the continent are cleanly absorbed by the
aggregate.  This allows the site to migrate within the continental providers
without renumbering and without any burden to those outside of the
continent. 

If routing optimality becomes an issue, having an abstraction action
boundary that is even one or more hops removed from the abstraction naming
boundary can further improve the situation.

The issue with this approach is again one of cooperation: those folks
performing the maintenance of the aggregation are NOT those that benefit
from it.  The up side is that if everyone were cooperative (you scratch my
back, I'll scratch yours), then mutual aggregation would distribute both the
costs AND the benefits.  If providers could be enticed to enter into such a
multilateral (and informal!) agreement, we could make significant progress.

Regards,
Tony


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