Subject: A lowest layer with location independent identifiers with more than one protocols

From: Pekka Nikander <[email-masked]>
Date: Mon, 8 Nov 2004 10:46:24 -0500

[Replies directed to hipsec-rg, be careful.]

As some of you may know, we had a workshop on "HIP and Related 
Architectures"
on Saturday.  There were a number of conclusions from the workshop; 
they will
be presented at the HIP RG on Saturday.  However, there were a couple 
ones that
IMHO may be important also to the multi6 folks, and I'd like to share 
them.

Firstly, it was determined that there seems to be some value of 
providing

  "a lowest layer that supports location independent identifiers"

In a way, that seems to be exactly what multi6 is trying to provide.

Secondly, some people expressed their discomfort with the HIP approach
of combining identifiers and security.  Ion Stoica and Scott Shenker
put it out nicely, saying that HIP provides

   A.  A mapping from a public key to an identifier, and
   B.  A mapping from an identifier to a set of locators

Based on this observation, we came to an analogy.  Consider the case
with current TCP and UDP.  They are on the same layer, and provide the
same kind of *identifier* abstraction.  However, they provide different
communication semantics.  In a way, one could perhaps characterise that
"UDP is TCP without congestion control".  (I know, that is not quite 
true,
but I wish you get the point.)

In the same way, there might be value to have more than one protocols
at the "lowest layer that supports location independent identifiers".
These multiple protocols would all provide the same kind of *identifier*
abstraction, but different semantics.  One of the protocols might be
HIP, with both A and B.  Another protocol might be something else, maybe
with just B without A.  That might be what multi6 is aiming for.

--Pekka Nikander