Subject: Re: [MOBILE-IP] MIER V01

From: Raja Narayanan <[email-masked]>
Date: Tue, 7 Dec 1999 16:02:48 -0600

Hello,

Responses prefixed by >>>

--Raja

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All,

Although this draft is better than its predecessor, I REALLY don't like the
way that the one octet is split up into a sub-type and flags.

I really don't see why a reserved bit field is necessary, and this limits
the
number of sub-types to 16.

>>> Well, the reserve bits are a nice way to facilitate some future
standization efforts for types that have already been used. Surely, we
REALLY don't have to just address problems that are at the tip of the nose.
Who knows, at some point someone may choose to add a flag to a type to mean
something.

>>> Having said that, we are open to the sentiments of the WG. If the
consensus is that reserve bits are useless then we would be more than happy
to take it out.

This seems to conflict with the statement in
the abstract "MIER describes a new extensions structure to Mobile IP to
make the extensions truly extensible." I think that truly here is a little
mis-leading since it is not infinitely extensible. We still have a maximum
number of extensions, and what we now have is 254 * 16, which should
give us a little longer, but it's hardly "truly extensible".

>>> Our original draft had a general extension which would have made it
truly extensible. I agree that 'truly' in the context of this version can be
reworded. We can reword it or re-introduce the general extension concept now
or at a later stage -- which ever the WG desries. Don't agree with the
comment that 254 * 16 would give us a 'little longer' ... 16 times what we
have today is non trivial.

Section 2.2 defines that this new extension can be carried within an
ICMP Router Discovery message. Why is that? I really don't see why we
need to change the format of the ICMP messages. Is this really a
requirement?

>>> Agreed. We will take the reference to ICMP Router Discovery message out.

Appendix A.1 is not in harmony with the new challenge draft. The new
challenge
draft reserves an SPI instead of a new identifier.

>>> We will make it harmonious.

PatC