ULA and RIR cost-recovery

Michael.Dillon at radianz.com Michael.Dillon at radianz.com
Thu Nov 25 12:46:55 UTC 2004


> The problem with this scheme is that it's only aggregatable if there's 
> some POP that lots of carriers connect to in the proper geographic 
> areas.  What is the carriers' incentive to show up -- peer? -- at such 
> points, rather than following today's practices?

Leaving aside the specifics of any particular geopgraphic
addressing scheme for the moment...

If we adopt a geographic addressing scheme for a part of 
the IPv6 space we are really saying that we expect a
part of the IPv6 network topology to be geographically
based. While it is convenient to think og geographical
divisions in terms of boundaries, in real world networks
the geographical divisions are defined by peering points
which the real world refers to as "major cities". So if
we do adopt a geographic addressing scheme it makes no 
sense at all for the RIRs to allocate these addresses to
entities that happen to be inside a specific geographic
boundary. However, it makes perfect sense to allocate
these geographic addresses to an entity who is peering
at one or more of the peering points within a geographic 
boundary.

This doesn't mean that everybody at the peering point
gets geographic addresses but it does mean that organizations
who have hierarchical networks with geographically
delineated subdivisions can get geographically aggregatable
space. 

For example, let's assume that one of the geographical divisions
is the Romance countries. Outside of these countries the geographical
address space for this region would consume exactly one
routing table slot, no more. Everyone would route the traffic
to the nearest network (using non-geographical addresses)
which peers at one of the peering points in Paris, Madrid,
Lisbon, Milan, Toulouse, etc. The global routing table
would be smaller because networks which do not need 
detailed global visibility will not be using normal PI
addresses.

Geographic addressing will only work if non-geographic addressing
also exists and if the geographic divisions are neither to
small nor too large. RIR boundaries are too large. Most
national boundaries are too small.

With IPv6, routing table size grows 4 times due to
the 128 bit addresses. With IPv6 routing table size
shrinks because most ASes only need one /32 route.
With IPv6 routing table size explodes because most
businesses want to multihome. With IPv6 and geographical
addressing, routing table size shrinks because most
multihomed businesses only need global visibility of
their routes within a larger geographical aggregate.

--Michael Dillon




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