RE: Architectural approaches to multi6

["Christian Huitema" <huitema@windows.microsoft.com>]

> I would NOT agree that there are no solutions in routing.
> That said, I think that a solution MUST involve having
> the transport NOT use the locator as a portion of the
> pseudo-header.  So at the very least, there must be host
> changes.

I disagree with Tony. There is a known solution, which is to use
multiple addresses per endpoint. This effectively provides a solution to
the aggregation/routing load dilemma by representing the routing graph
as the superposition of several trees, all rooted in the DFZ. I would
contend that this is the only solution in case of host multi-homing
(e.g. GPRS+WIFI): in this case, the independent trees are joined at
their leaves. 

This is a suboptimal but workable solution in case of site multi-homing,
as the independent trees are joined at the "site" branch. How suboptimal
depends on the size of that branch vs. the size of the tree. In
practice, this is not an issue for very small sites, e.g. single subnet
sites, as the branch is tiny. It is not a real issue either for very
large branches, e.g. sites such as IBM or Microsoft, as the branch is so
large that it can be considered "close to the root" and given its own
number. 

We have an issue for the medium size branches, which can be solved
either by a routing solution (find a way to route more prefixes) or by a
site engineering solution (better management to make medium sites look
like large sites).

-- Christian Huitema