Subject: [mobile-ip] Unresolved issue #22: SHOULD or MUST for CN RO?

From: Jari Arkko <[email-masked]>
Date: Sun, 05 May 2002 12:41:34 +0300

(List of issues at http://www.piuha.net/~jarkko/publications/mipv6/MIPv6-Issues.html -
please submit your issues to the list, I can put them in the directory)

Background: Draft 17 will have a section that describes the requirements
for correspondent nodes. The initial attempt at this text is the
following:

    Since any IPv6 node may at any time be a correspondent node of a
    mobile node, either sending a packet to a mobile node or receiving a
    packet from a mobile node, the following requirements apply to ALL
    IPv6 nodes (whether host or router, whether mobile or stationary):

     -  Every IPv6 node MUST be able to process a Home Address option
        received in any IPv6 packet.

     -  Every IPv6 node SHOULD be able to participate in a return
        routability procedure, process Binding Update messages, and to
        return a Binding Acknowledgement option if the Acknowledge (A)
        bit is set in the received Binding Update.

     -  Every IPv6 node SHOULD be able to maintain a Binding Cache of the
        bindings received in accepted Binding Updates.

Samita Chakrabarti comments on this: "IMHO, SHOULD is quite weak
statement. The whole point of doing route optimization is to save
round-trip time.  Now that we are solving the security issues, I think
route optimization is the feature that a CN (a CN could be a MN) must
implement. But obviously there SHOULD be a knob on MN side to turn it
off and on.

Without RO, the roundtrip time now is even longer through the
reverse tunnel. Route optimization should be "MUST" for CN, IMHO."

Question: Is the text right? Should the keywords be MUST?

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From: Vijay Devarapalli <[email-masked]>
Date: Mon, 06 May 2002 12:54:17 -0700

> Question: Is the text right? Should the keywords be MUST?

Ofcourse 'MUST'.

vijay

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From: "James Kempf" <[email-masked]>
Date: Mon, 6 May 2002 13:31:19 -0700

> > Question: Is the text right? Should the keywords be MUST?

Since the CN can be any node in the IPv6 Internet,  doesn't this need to
be passed by IPNG?

            jak

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From: Pekka Savola <[email-masked]>
Date: Tue, 7 May 2002 00:18:07 +0300 (EEST)

> Since the CN can be any node in the IPv6 Internet,  doesn't this need to

Definitely. (Or it will probably come back at the w.g. at IESG last 
call..)

It's easy for MIPv6 implementors and advocates to say MUST, but some
people, more skeptic about the deployment of mobility certainly disagree.

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords

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From: Francis Dupont <[email-masked]>
Date: Tue, 07 May 2002 11:44:05 +0200

=> this is exactly what I think, i.e. the question is out of the scope
(and charter) of the MIP WG.

Regards

[email-masked]

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From: Keiichi SHIMA / 島慶一 <[email-masked]>
Date: Wed, 15 May 2002 13:26:24 +0900 (JST)

Hi,

From: Jari Arkko <[email-masked]>

>         bindings received in accepted Binding Updates.

As many other people reply, I thinks this topic should be discussed in
the ipng wg too.

In my personal opinion, SHOULD is OK.

If many IPv6 implementors think that MIP6 is useful, want to use it,
want to make it effective, they eventually support a RR.  A RR is a
key function of MIP6, but not essential.  We can deploy MIP6 even if a
RR is not mandatory.  Couldn't we leave the decision to the
implementors?

# I may be too optimistic...

Regards,

---
Keiichi SHIMA
IIJ Research Laboratory <[email-masked]>
KAME Project <[email-masked]>