Subject: Re: [rrg] definitions - alternate view

From: [email-masked] (Noel Chiappa)
Date: Wed, 8 Apr 2009 12:38:56 -0400 (EDT)

{Found in an editor buffer - sorry if this is a bit late.}

    > From: William Herrin <[email-masked]>

    > I'm suggesting that how we've been thinking about locators and
    > identifiers is not quite right. The error was revealed by our attempt
    > here to give them more precise definitions. They're eluding our
    > attempts at rigor.

The problem is not that past thinking was lacking in rigor. (Please note that
the _original_ published definition of 'locator' was _extremely_ rigorous - it
meant a hierarchically structured name for a map node.)

The problem, _in part_, is that the terms, _over time_, have come to have
somewhat different meanings to different people. Hence my prior comment:
 
    >> the best we can do for the Big Three (address, locator, identifier) is
    >> to come up with definitions which reasonly match what they mean to
    >> _most_ people now, and hope that the outliers eventually give up on
    >> their idiosyncratic personal definitions ...
    >> ... Note that the definitions for those three will have to be a little
    >> 'loose', because if you make them _more_ specific, you will start to
    >> loose people from the "_most_ people" pot above.

(I said 'in part' because _some_ people probably aren't thinking about this
rigorously.) But the point remains that much as you and I might want rigor,
that attempt will inevitably do a Titanic when faced with actual usage in a
wide community.

    > Defining address in terms of where you are .. topologically [is not
    > very plausible]

The term 'address', perhaps, for the reasons you give below (although I would
claim this doesn't apply to 'locator').

    > ... offers a very slippery definition. It's hard to give it any kind of
    > rigor in the face of anycast, multicast and load balancing.

Not to mention its use at the transport layer to name the entity at the other
end of a reliable end-end connection....

But you are absolutely right - 'address' is probably irretrievably broken.
The best we can do, probably, is say something akin to 'as used in deployed
IPv4', and then list its uses there.

	Noel