RE: Geo pros and cons

["Tony Li" <Tony.Li@procket.com>]

|    From: Tony Hain [mailto:alh-ietf@tndh.net] 
|    > As we concluded many years ago: for addressing to scale, it 
|    > has to match the topology.  If addressing does not match the 
|    > topology, then additional information in the form of longer 
|    > prefixes must be advertised into the routing subsystem.  
|    > Ergo, if one chooses geographic address, one must force only 
|    > geographically based links.  Anything else destroys the 
|    > aggregatability of the address assignment.  Since we, as IETF 
|    > members, cannot decree where folks will connect, geo 
|    > addressing is a nice theorectical goal which is unimplementable.
|    > 
|    Only if you insist on the absolute minimum size routing 
|    table. 


If we were to insist on the minimum size routing table, we would
have to decree that the entire Internet was a single binary tree.
No thanks.


|    As you
|    said above, economics drive the decisions of network 
|    managers. There is
|    a balance somewhere here between circuit costs for random 
|    interconnects,
|    and the cost of the routing table to support that. All we 
|    need to do is
|    provide a mechanism that allows for rational decisions 
|    about system cost
|    to be made. A mechanism that results in lower costs for those that
|    choose to multihome in a small geographic region will win out.


If we could provide a mechanism that allows for globally rational
decisions about system cost to be made, we could and would deploy
it today.  You may recall from the CIDR wars that we briefly 
discussed and tried to encourage a mechanism that caused economic
pushback for individual routes in the DFZ.  It never went anywhere.
If you want to charge to accept routes and your competition doesn't,
you lose.

This boils down to simple game theory: we can expect that almost
everyone will act in their own best interest, at the expense of
the common good.  We are not empowered to edict the economics of
the situation, so we'd best come up with a solution that organizes
the chaos that others will foist upon us.

Tony