[ppml] geo addressing

Rich Emmings rich at nic.umass.edu
Thu Nov 17 15:09:36 EST 2005

On Thu, 17 Nov 2005, Michael.Dillon at btradianz.com wrote:

> Geotopological addressing is not a traffic engineering tool.
> It does not pretend to solve all corner cases in Internet
> operations or architecture. What it does do is allow a much
> larger number of organizations to multihome in their
> city without consuming slots in the global routing table.
> Therefore it helps you reroute traffic via Chicago and LA
> because there will be more space in the global routing table
> for those more-specifics.

Based on past events, same city homing doesn't strike me as scaleable 
anymore, in even moderate availablity environments.  Geographic 
diversification of the infrastructure seems more the trend, so one event 
(nature, man, etc) doesn't effect all.  So, say I'm homed in Boston and NYC. 
Which address space do I announce, the Boston space in NYC or the NYC space 
in Boston, or my direct assignments which are neither?

> This was done on purpose. The feeling was that people would make
> less dialling mistakes if the similar area codes were far apart
> geographically.

Story I had, back when dialing was done with pulses, is the areas with the 
most customers (LA, NYC, Chicago) got the codes with a low number of clicks 
(212, 213, 312) and least (Alaska, Hawaii ) got more clicks, i.e. 907, 808. 
The longer it takes to connect, the longer you tie up the operator board, so 
there was an interest in reducing that by AT&T.  (one ref: 

>> An IP address is just an address and nothing more.
> That has not been true since people began filtering on different
> prefix lengths in different address ranges. Around the time CIDR
> was invented.

No, it's still an address.  A CIDR block is a notation for a group of 
addresses related to routing traffic in a particular fashion.  I could group 
addresses together in a different way, for example, load balancing selection 
using bits from the last byte of the address.

> Geotopological addressing is not proposed as a replacement for
> the classic IPv6 address allocation plan. It is proposed as an
> additional addressing plan with different rules which runs
> alongside the classic plan and offers organizations a choice.
> In effect, it brings market principles to bear in RIR policy
> by making classic addressing compete with geotopological addressing.

I'm not sold on why is this needed, and question if it represents 
something that will move IPv6 implementation forward.

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