[ih] Internet without entrenched factions?

[Noel Chiappa]

    > From: Brian E Carpenter
    
    > Well, there's one area that stills needs to be fixed ... We don't know
    > how to support site multihoming in a competitive environment for tens
    > of millions of small and medium enterprises.

I thought about that pretty extensively at one time - let me see if I can
remember my thoughts about it.

Basically, TANSTAAFL. Site multi-homing gives benefits; benefits usually
aren't free; somebody has to pay. My recollection is that trying to get the
path-selection subsystem to do all the work needed to support widespread
site multi-homing (with just single locators for things in the multi-homed
site) is just too expensive.

(That's because path selection for such destinations has to happen over a
wider area of the network connectivity graph - so traffic can take multiple
paths to get to them. Of course, the current Internet doesn't even _have_ a
general Abstraction Action Boundary mechanism, so once the visibility of a
topological abstraction spreads beyond a local area - say, its Abstraction
Naming Boundary - it has to be globally visible. So millions of small
multi-homed enterprises means millions of globally visible destinations, with
Internet-wide path-selection overhead costs for them all.)

In an internet using a Destination Vector path-selection subsystem, one has
to do it with multiple locators. (In other words, multiple Abstraction Naming
Boundaries overlapping over each multi-homed site.) That allows one to have
less globally visible topological abstractions. Then the name->locator
translation database system has to return all the multiple locators for any
given multi-homeddestination - and the entity looking it up has to pick the
one it is going to use. Yes, more expensive - but, like I said, TANSTAAFL.

In an internet using a Map Distribution path-selection subsystem, one can
hand out a small, more detailed, local map. (This is basically what people do
on the roads, when they are going to a multi-homed road destination.) There
are a whole bunch of complications havind to do with pat set-up/installation
but I'm going to pass over them because I doubt anyone cares.

	Noel