Subject: RE: [RRG] draft-rja-ilnp-intro-01.txt

From: [email-masked] (Noel Chiappa)
Date: Sun, 3 Aug 2008 09:07:38 -0400 (EDT)

> From: "Tony Li" <[email-masked]>

    > one way would be to put the identifier into a transport option, for
    > example, and then only include it in packets when there is a change in
    > address. You would continue to use locators as the pseudo-header in the
    > meantime.

Did you mean 'continue to use the identifiers in the pseudo-header in the
meantime'? That's what I did in a proposed TCP mod which added separate
identifiers, which I did back in the NSRG timeframe. By putting the
identifiers into the pseudo-header, and therefore into the checksum, you
'implicitly' include them into every packets, even though they aren't actually
in the packets as a distinct field.

That's almost as robust as actually including them in each packet, but doesn't
have the overhead. Also, it allowed us to efficiently make the identifiers
variable-length (so that new ones could be allocated locally, without having
to go back to an issuing agent - something we deemed an important capability);
you can precompute the partial checksum of that part of the pseudo-header and
store it so you don't have to recompute it on each packet.

This was, of course, back before I decided that 'jack-up' was a more viable
deployment option than modifying all the hosts in the world....

	Noel

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