Fwd: A comment about MAST

[Dave Crocker <dhc@dcrocker.net>]

Forwarded, at the author's request. my reply follows.

d/
--
 Dave Crocker <dcrocker-at-brandenburg-dot-com>
 Brandenburg InternetWorking <www.brandenburg.com>
 Sunnyvale, CA  USA <tel:+1.408.246.8253>

===== Forwarded message =====
From: Eugene M. Kim <gene@nttmcl.com>
To: "Dave Crocker" <dcrocker@brandenburg.com>
Date: Monday, September 8, 2003, 10:16:17 PM
Subject: A comment about MAST

Greetings,

I have a comment regarding your MAST proposal; I apologize if this have
already been addressed before:

My understanding of the architectural model as described and illustrated
in 4.1 suggests that the address changes and handovers will be
completely hidden from upper-level applications so they will still
identify the connection as between IP.a, Port.l, and IP.y, Port.r
(communication endpoints).  Although this is the least intrusive
approach, I think this is not enough if applications that `leak' those
endpoints over the wire were to benefit from MAST.  This is somewhat
similar to the classic NAT problem.

My suggestion is to expose the address changes to upper-level
applications through some backward-compatible API extension, which shall
notify applications that addresses are being added to or removed from
the local or remote endpoint identifier.  Simple applications that do
not care about nor use endpoint identifiers can safely ignore this new
API and still work across address changes.  Complex applications (and
protocols they implement) that do care about and use endpoint
identifiers over the wire can be modified to utilize MAST and this new
API so they can propagate address changes accordingly.  If they ignore
the new API, their operation will break at the moment an original
endpoint address, local or remote, becomes invalid; but since they will
break anyway without MAST at all at that moment, this seems to be a
non-issue.

I am not suggesting that the MAST proposal should define such APIs with
it; IMO they are better left out as future work items as individual
operating systems implement MAST.

Regards,
Eugene

P.S. Which is the main discussion list for MAST, and could you forward
this to the list if there is one?
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