Subject: [nemo] Closing Issue 16

From: Vijay Devarapalli <[email-masked]>
Date: Tue, 02 Dec 2003 15:56:51 -0800

hi all,

this issue was about support MIPv6 Home Agents that do not support
mobile routers. we initially modified DHAAD to return only the list
of home agents that support mobile routers. but Pascal and Jari
argued that the protocol is more robust if the Home Agent echos a
bit in the binding acknowledgement to indicate to the mobile router
that it has setup forwarding for the mobile network.

so I changed the format of the binding ack to include a new flag.
this flag is set when the Home Agent which processed the binding
update supports mobile routers and the mobile router flag in the
corresponding binding update was set to 1.

change the binding ack format

4.2. Binding Acknowledgement

    A new flag (R) is included in the Binding Acknowledgement to indicate
    that the Home Agent which processed the corresponding Binding Update
    supports Mobile Routers.  The flag is set only if the corresponding
    Binding Update had the Mobile Router flag (R) set to 1.  The rest of
    the Binding Acknowledgement format remains the same as defined in
    [1].

         0                   1                   2                   3
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
                                        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                        |   Status      |K|R|  Reserved |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |         Sequence #            |           Lifetime            |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                                                               |
        .                                                               .
        .                        Mobility options                       .
        .                                                               .
        |                                                               |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       Mobile Router Flag (R)

          The Mobile Router Flag is set to indicate that the Home Agent
          which processed the Binding Update supports Mobile Routers.  It
          is set to 1 only if the corresponding Binding Update had the
          Mobile Router flag set to 1.

       For a description of the other fields in the message, see [1].

    This document also introduces the following new Binding
    Acknowledgement status values.

       140     Mobile Router Operation not permitted

       141     Invalid Prefix

       142     Not Authorized for Prefix

       143     Forwarding Setup failed

    Status values less than 128 indicate that the Binding Update was
    processed successfully by the receiving nodes.  Values greater than
    128 indicate that the Binding Update was rejected by the Home Agent.

change section 5.3

5.3. Receiving Binding Acknowledgements

    The Mobile Router receives Binding Acknowledgements from the Home
    Agent, corresponding to the Binding Updates it sent.  If the Binding
    Acknowledgement status is set to '0' (Binding Update accepted) and
    the Mobile Router flag (R) is set to 1, the Mobile Router assumes
    that the Home Agent has successfully processed the Binding Update
    and has set up forwarding for the Mobile Network.  The Mobile Router
    can then start using the bi-directional tunnel for reverse tunneling
    traffic from the mobile network.  If the Mobile Router flag (R) is
    not set, then the Mobile Router concludes that its current Home Agent
    does not support Mobile Routers and performs Dynamic Home Agent
    Discovery again to discover Home Agents which support Mobile Routers.

modify section 6.6 to say

    The Home Agent sets the status code in the Binding Acknowledgement
    to '0' (Binding Update accepted) in order to indicate to the Mobile
    Router that it successfully processed the Binding Update.  It also
    sets the Mobile Router flag (R) to indicate to the Mobile Router that
    it has setup forwarding for the Mobile Network.

a MIPv6 Home Agent will not set this flag.

let me know if this looks good.

Vijay

---

From: Ryuji Wakikawa <[email-masked]>
Date: Wed, 03 Dec 2003 15:34:54 +0900

Hi Vijay

one comment

>     the Binding Acknowledgement format remains the same as defined in

If lecacy HA replied with successful status code without Rbit, MR should
de-register its host binding from the HA. no?
Otherwise, it HoA is generated from the home link (MIP mode), DAD will
be occured at the home link. 
regards
ryuji

> let me know if this looks good.

regards,
ryuji

---

From: Ryuji Wakikawa <[email-masked]>
Date: Wed, 03 Dec 2003 15:34:54 +0900

Hi Vijay

one comment

regards,
ryuji

---

From: Jari Arkko <[email-masked]>
Date: Wed, 03 Dec 2003 09:50:06 +0200

> let me know if this looks good.

It does. Thanks! I agree with Ryuji that you should
require a de-register if the home agent turned out to
be plain MIPv6 only.

--Jari

---

From: Jari Arkko <[email-masked]>
Date: Wed, 03 Dec 2003 09:50:06 +0200

--Jari

---

From: Vijay Devarapalli <[email-masked]>
Date: Wed, 03 Dec 2003 09:48:15 -0800

> be occured at the home link. 

agree. I will add some text.

Vijay

---

From: Vijay Devarapalli <[email-masked]>
Date: Wed, 03 Dec 2003 09:48:15 -0800

Vijay