RE: (multi6) requirements draft comments

["Tony Hain" <alh-ietf@tndh.net>]

J. Noel Chiappa wrote:
>     > have an implicit metro context.
>
> You clipped the next line:
>
>     > would share the same one-level-up topological naming entity

Sorry I should have been more precise. There is an implicit geographic
context which modifies the scope of the topology graph.

> (You can fine a picture of some of this process here:
>
>     http://users.exis.net/~jnc/tech/routing_slides.html

Your picture is too simple to be useful in addressing the scope of this
problem. Consider that A3 is connected to 'other stuff'. Your subsiquent
abstraction to X would still be valid, but depending on where in 'other
stuff' that connection occured you might get different answers for the
topology name of X, yet the abstraction is too simple to explain why.

> Now, do the same thing for all the other local ISP's hardware
                                           ^^^^^
This focus on *local* is the basic problem. The actual topology
frequently connects both at some local level and pulls in a few very
remote ISPs. Consider MegaRandomCorp which has connections to 6 ISPs in
the SF area, but on the same set of border routers has direct circuits
to an ISP in London, Tokyo, and Sydney. At the same time RandomMegaCorp
has connections to 3 of the same SF, Tokyo, and Sydney ISPs, but a
different one in London.

> The *key* difference here from metro is that I *start* with the actual
> connectivity map, placing no constraints on how it is
> connected. (E.g. there
> may be no direct link from Ci to Dj, except through the
> customer nodes -
> which of course do not forward traffic.) From that, I then
> asssign addresses.

If you fold the above complexity into your graph along with the other
~12000 ASs that are prefix origins today, and managing the
topology-names becomes an administrative burden as topology is
constantly shifting.

> the users have to renumber when they change providers, and

Actually they have to renumber everytime their neighbors change
providers as well, because the entire graph changes around them.

Tony