Re: [RRG] ALT's strong aggregation often leads to *very* long paths

[jnc@mercury.lcs.mit.edu (Noel Chiappa)]

    > From: Robin Whittle <rw@firstpr.com.au>

    > I am keen to know what you and others think of my critique of ALT's
    > core design principle

Alas, I haven't had the time to study ALT in detail, so I can't help here.

    > strong address aggregation being at odds with the need for short
    > total path lengths.

In both ALT (I think - perhaps I'm confused about this detail of ALT, if so
someone please enlighten me) and LISP+CONS, only the first/first-few data
packets (i.e. until the EID->RLOC mapping gets propogated back to the ITR)
will be sent (inefficiently) along the server hierarchy; after that, they
go direct. Is this slight temporary inefficiency really that important?

    > CONS didn't refer to its CDRs and CARs as "routers", but like ALT's
    > routers, they formed a mesh and/or tree structure for passing messages
    > back and forth between ITRs and ETRs

I responded to this in a previous message: unlike DNS (which requires the
entity desiring a mapping to potentially communicate directly with each node
which is part of the path through the resolution hierarchy, in turn - i.e.
first the root, then .EDU, then .MIT.EDU, then .LCS.MIT.EDU, etc), CONS does
this all internally, and passes only the final answer to the requester. (I
gave some of what I perceived to be the rationale for this design choice in
that same message.)

	Noel

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