Re: [homenet] draft-boutier-homenet-source-specific-routing-00

[Juliusz Chroboczek <[e-mail]>]

> Does the algorithm you propose implement the conceptual forwarding
> algorithm in [TROAN], then?

I've refrained from criticising your draft, since I appreciate people
taking the time to write legible, thought out drafts and thus sharing
their work with others.  However, I do not think that your "conceptual
forwarding algorithm" is a suitable basis for further work on
source-specific routing.  While I am glad to acknowledge that this
draft appears to be technically correct and was published before
I even started seriously thinking about source-specific routing,
I have no intention to base my work on what I believe is a flawed
formalism.

On the one hand, your "conceptual forwarding algorithm" is impossible
to implement directly on any operating system known to me.  On the
other hand, it's expressed in operational terms, with uselessly
complex data structures (two-level routing tables? eek!), which makes
it more difficult to understand than a purely abstract specification.

Look, given the right concepts, your "conceptual forwarding algorithm"
can be defined in one sentence:

  (d, s) pairs are ordered according to the lexicographic product of
  the longer-prefix orderings

This is a proper abstract formulation, and one that doesn't uselessly
introduce data structures where they don't belong.  This is what I've
attempted to do (without using order-theoretic language) at the
beginning of Section 2.2.2.

Not only is your formalism clumsy, but you don't even explain in prose
or justify the particular behaviour that you have chosen for
source-specific routing.  The reason for this particular behaviour was
explained to me by Fred Baker by private mail, and a summary of our
discussion appears in Section 2.2.2 (with proper credit given to
Fred).

Once again: I'm glad to cite your work, and I'm glad to recognise that
you were there first.  Please do not ask me, however, to reformulate
my work to fit a formalism that I happen to find deficient.

-- Juliusz