[netext] Discussion about "Retransmit Message Identifier Option"//Re: Agenda Requests received

[Xiangsong Cui <[e-mail]>]

Good idea.

I have a question about item 5, "Retransmit Message Identifier Option".
I ever posted a mail on 27 June, but it was ignored. So I copy the mail 
here:

The draft says:
----------------------------------------
1.  Introduction

   The Proxy Mobile IPv6 protocol [RFC-5213] does not provide the
   ability for the sender of a signaling message to mark retransmitted
   messages with a proper tag, so the receiver can differentiate between
   the original message to a retransmitted message.  This semantic is
   important for the receiver to determine when to ignore processing a
   retransmitted packet, or for various other reasons.
---------------------------------------------

Is the motive is just to distinguish the original and retransmitted PBU?


I ask this question just because I think it is unnecessary. The reason is:

1, section 6.1.7 [RFC3775] shows there is a "Sequence #" field in BU
message, and
   section 11.8 [RFC3775] says:
   --------------------------------------------------------
      Retransmitted Binding Updates MUST use a Sequence Number value
   greater than that used for the previous transmission of this Binding
   Update.
   ----------------------------------------------------
   So the BU messages are different for their sequence number.

2,  section 6.6 [RFC5213] says:
     -----------------------------------------
     6.6.  Acquiring Mobile Node's Identifier

   All the network entities in a Proxy Mobile IPv6 domain MUST be able
   to identify a mobile node, using its MN-Identifier.  This identifier
   MUST be stable and unique across the Proxy Mobile IPv6 domain.  The
   mobility entities in the Proxy Mobile IPv6 domain MUST be able to use
   this identifier in the signaling messages and unambiguously identify
   a given mobile node.  The following are some of the considerations
   related to this MN-Identifier.
   -------------------------------------------
   In [RFC3775] LMA MUST distinguish the mobile node by the MN-ID.
   PBU message format also shows there is a sequence # field in PBU
   message and "Mobile Node Identifier option" is valid.

3, section 6.9.4 [RFC5213] has specified the rule for Retransmissions and
Rate Limiting.


For these reasons, I believe the LMA can recognize the duplicate PBUs.
The LMA has been capable of making binding for the first PBU and ignore
other PBUs for the same mobile node.


Do I make any mistakes? and why we need a new extension?


Because I will not go to the meeting, I want to discuss the topic in list
before the meeting.

Thanks and regards

Xiangsong

=================================================
----- Original Message ----- 
From: <[e-mail]>
To: <[e-mail]>; <[e-mail]>
Sent: Wednesday, July 15, 2009 1:34 AM
Subject: Re: [netext] Agenda Requests received


>
> As of 7/14 the chairs have received requests for agenda slots at IETF75.
> We would like to encourage WG members to review the I-Ds and provide
> feedback on the list prior to the meeting itself.
>
> -Chairs
>
>
> Agenda requests received:
>
> 1. Runtime LMA Assignment Support for Proxy Mobile IPv6
>   I-D: draft-korhonen-netext-redirect-02
>   Jouni Korhonen - 10 Mins
>
> 2. Localized Routing
>   PMIPv6 Localized Routing Problem Statement
>   I-D: draft-liebsch-netext-pmip6-ro-ps-01.txt
>   PS and Scope discussion    10 Mins
>   Solutions        15 Mins
>   Marco Liebsch et al.
>
>   Proxy MIP extension for local routing optimization
>   I-D: draft-wu-netext-local-ro-02.txt
>   Behcet Sarikaya    5 Mins
>
> 3. Tunnel Negotiation for Proxy Mobile IPv6
>   I-D: draft-xia-netext-tunnel-negotiation-01.txt
>   Frank Xia        10 Mins
>
> 4. Mobile Node Group Identifier Option:
>   I-D: draft-gundavelli-netext-mn-groupid-option-01
>   Sri Gundavelli    10 Mins
>
> 5. Retransmit Message Identifier Option:
>   I-D: draft-gundavelli-netext-pmipv6-retransmit-option-00.txt
>   Sri Gundavelli    10 Mins
>
> 6. Mobility session suspend
>   I-D: draft-muhanna-netext-mobility-session-suspend-00.txt
>   Ahmad Muhanna    10 Mins
>
> 7. Trace Control Support for Proxy Mobile IPv6
>   I-D: draft-wang-netext-trace-control-00.txt
>   Yungui Wang        10 Mins
>
> 8. Multihoming extensions for Proxy Mobile IPv6
>   I-D: draft-bernardos-mif-pmip-00.txt
>   Telemaco, Pierrick and Carlos    10 Mins
>
> 9. 3GPP MN-AR interface
>   I-D: draft-melia-netext-3gpp-mn-ar-if-00.txt
>   Telemaco                5 Mins
>
> 10. Service Flow Identifier in Proxy Mobile IPv6
>    I-D: draft-hui-netext-service-flow-identifier-00.txt
>    Min Hui        10 Mins
>
> 11. Connection Identifier for Proxy Mobile IPv6
>    I-D: draft-wolfner-netext-pmip6-connid-00
>    Jouni Korhonen    5 Mins
>
> 12. Bulk Re-registration for Proxy Mobile IPv6
>    I-D: draft-premec-netlmm-bulk-re-registration-02
>    Jouni Korhonen    5 Mins
>
> 13. Partial Handoff Support in PMIPv6
>    I-D: draft-jeyatharan-netext-pmip-partial-handoff-00
>    Mohana Jeyatharan
>
>
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