Subject: [MEXT] Comments on draft-ietf-monami6-mipv6-analysis-04

From: "George Tsirtsis" <[email-masked]>
Date: Tue, 20 Nov 2007 17:23:50 +0000

Hi All,

I have been reading draft-ietf-monami6-mipv6-analysis-04 and I have to say I
am a bit confused.
The draft certainly contains a lot of interesting material but the
information contained may not be structured as well as it could or should.
The following comments might seem a bit too generic and I apologize in
advance if some of these issues have already been discussed or if the
authors are in the process of fixing.

Section 5 provides a comprehensive list of multi-homing scenarios. For each
case a description of the scenario is given e.g., (1,1), (1,n) etc and then
the "current situation with MIPv6" is discussed. This latter part, I think,
needs to be split in two parts. One part really discussing what MIPv6 offers
in the given scenario and then possibly at a high level what improvements or
additional functionality could be considered. At the moment these two things
are done together resulting in a lot of confusion...at least to me :-) In
general a possible restructuring of the document would discuss specific
scenarios, identify how MIPv6 deals (or does not deal) with each scenario (
i.e., section 5) and then a mini problem statement for each MIPv6
"inadequacy" could be provided (section 6...more or less).

Another general observation is that some terms are used lightly and are not
defined properly. For example, the terms "transparent", and "load sharing"
are causing me concern in the context of the document. Certain events are
characterized as "transparent" or "non-transparent" but it is not obvious to
who the transparency refers to (the MN? the HA? the CN? other?). "Load
sharing" some times seems to refer to running apps on different HoAs, or
even interfaces (?), and other times seems to refer to pointing flows
running on the same HoA to different CoAs (but then how is this different
from Flow Distribution?). "Reliability" also means different things at
different times e.g., ability to survive CoA failure, HoA failure, HA
failure etc....but it is not always clear which type of reliability is
talked about.

Finally, the document discusses multiple HoAs for the same MN as if MIPv6 is
already somehow covering this case. It is not, for example, made clear that
as far as MIPv6 is concerned, each HoA represent a separate MIPv6 session,
and that an MN with multiple HoAs has to maintain multiple MIPv6 session,
which from the HA's perspective look like they belong to different MNs
altogether. This is implied if you read between the lines but the
significance of the point is lost, while the discussion also fails to make
clear whether such an assumption should be reexamined.

Best Regards
George
P.S.: Just so I know...are the monami6 (and drafts of other WGs now under
MEXT) be republished as draft-ietf-mext-?
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