RE: geo short vs long term? [Re: Geo pros and cons]

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

Noel, well said.

More points: there are worse things than no decision.  That
would be the clearly wrong decision.  We could, for example,
choose to aggregate locators based on the lexographical 
ordering of the user's first name.  We could choose not to
aggregate and end up with another swamp.

As to the issues with 'proving' that geo won't work, let me
point out the very simple reasoning:

- The Internet is continually growing at an exponential rate.
  Most people seem to peg the growth rate at 100% per year
  currently.  The exact number is not an issue.

- In the past, we've estimated that 10% of all sites would
  multi-home.  Let's assume a constant rate of 10% of the
  world is an exception to the default aggregation rules
  that we pick.

- From the above two, we can reason that our exception rate
  is going to continue to grow exponentially.  Note that
  the rate of absolute growth is more of an issue than the
  exception rate.  

- Moore's law for memory suggests that memory sizes will
  double about every two years.  However, memory speeds will
  not keep up.

- Packet lookups are a function of memory bandwidth, so to
  sustain Internet bandwidth growth of 100% per year, we need
  to also increase memory bandwidth by about 100% per year.
  Using bigger, slower memories is not a realistic option.

- Thus, the routing table really needs to be constrained to
  grow at about Moore's law for memory.  

- If the exceptions are growing at about 100% per year, and
  the memories are growing at about 100% every TWO years, then
  regardless of the starting point, the exceptions will overtake
  technology.

- Therefore, we must find some mechanism that prevents the
  exceptions from growing at 100% per year.  In short, the
  number of longer prefixes that are injected into routing
  cannot be a constant fraction of the number of sites that
  join.

- Since everyone and their brother will want an exception
  for anything that they want to do that is outside of the
  norm, the norm MUST support almost every possible situation.
  Multihoming, in particular, must not cause exceptions.
  Even a constant percentage of multihomers must not cause
  exceptions.

- For reasons that I've already explained, the economics
  of links in a geo system cause many sites to be exceptions.

- Therefore, geo addressing leads to a system that will not
  scale for the long term.

QED

Tony


|    -----Original Message-----
|    From: J. Noel Chiappa [mailto:jnc@ginger.lcs.mit.edu] 
|    Sent: Thursday, April 03, 2003 4:38 AM
|    To: multi6@ops.ietf.org
|    Cc: jnc@ginger.lcs.mit.edu
|    Subject: Re: geo short vs long term? [Re: Geo pros and cons]
|    
|    
|    Look, everyone, this is all really stupid.
|    
|    Geographic addressing has been discussed extensively about 
|    17 times in the
|    IETF, and every time it has been rejected. Discussing it 
|    one more time is not
|    going to change this. There is *never* going to be a rough 
|    consensus *in
|    favour of* geographic addressing. There will *always* be a 
|    lot of people
|    against it - enough to stop it in the proposal stage.
|    
|    The really sad thing is that something productive might 
|    have been done with
|    all this time and energy that's being wasted.
|    
|    	Noel
|    
|