[Mobopts] Re: [multimob] Bar BOF in Chicago

Thomas C Schmidt <schmidt@fhtw-berlin.de> Tue, 24 July 2007 15:28 UTC

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Date: Tue, 24 Jul 2007 17:31:32 +0200
From: Thomas C Schmidt <schmidt@fhtw-berlin.de>
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To: Wu Qian <wuqian@cernet.edu.cn>
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Cc: multimob@ietf.org, mobopts <mobopts@irtf.org>
Subject: [Mobopts] Re: [multimob] Bar BOF in Chicago
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Hi Wu,

many thanks for your feedback - please see comments inline

------------- snip ------------------------
For the problems which mobile multicast faces

• I think the main problems can be divided into
2 categories, and then we can explain the
problems of multicast caused by mobility
– For the User side, 2 main problems:
• Multicast packet loss percentage mainly caused by
• packer transmit delay (related Average to the path
length of multicast packet, triangular routing would
make parameter this worse)

------------- snap ------------------------

TS => Yes, agree. Additional disturbances arrive from jitter, as 
discussed in the introduction of the draft.

Another key issue: the address duality problem.

The idea of the PS-draft is - from a fairly general level of abstraction 
- to look behind the scene, i.e., to identify issues and causes in more 

The reason for this: The PS-draft is meant to serve as comprehensive 
overview and analytical fundament for future designers of mobile 
multicast protocols.

------------- snip ------------------------

For the problems which mobile multicast faces (con.)

– For the Network side, 3 main problems:
• Multicast packet efficiency (use delivery related to the of tunnel)
• Multicast maintenance overhead (related to the design of mobile 
multicast scheme)
• The stability of multicast tree (related the way of updating multicast 
tree after a handoff event)

------------- snap ------------------------

TS => D'accord. Please don't forget convergence speed and robustness of 
the mobile multicast routing schemes.

Fairly central issues derive from deployment: We should closely look at 
  solutions which have a realistic chance for deployment, e.g., by 
staying close to unicast mobility management schemes.

------------- snip ------------------------

For the solutions
• Users always move around within a definite scope, such as within a 
building when they are working
• Hierarchical structure is useful in mobile multicast
– Can shield the local movement from outside
– Can efficiently reduce the change of the main
multicast delivery tree
– Can decrease the multicast protocol overhead related handoff
– It is an important category of mobile multicast
solution and I suggest it be written in solution, the draft

------------- snap ------------------------

TS => Yes, you're right. Actually this approach is taken in draft 
http://www3.tools.ietf.org/html/draft-schmidt-waehlisch-mhmipv6 , which 
is mentioned in the solutions section.

Of course, the brief survey over the solution space mainly consists in 
reference pointers ... to keep the document within readable bounds :-)

Best regards & hope to see you in Vancouver


Wu Qian wrote:
> Hi Behcet, 
> I'm interested in this BOF and write some comments on the 
> draft-irtf-mobopts-mmcastv6-ps-01.txt.
> But I can't go to Chicago this time, and the second author 
> Dr. Deng Hui will attend the bar bof of multimob.
> Best Regards,
> Wu Qian
> CERNET & Network Research Center of Tsinghua University
> Tel: +86-10-62603327, +86-13911189166			 
> wuqian@cernet.edu.cn
> 2007-07-24
> ----------Original Message----------
> From: Behcet Sarikaya
> Date: 2007-07-14 03:24:33
> To: multimob@ietf.org
> CC: townsley@cisco.com; Jari Arkko
> Subject: [multimob] Bar BOF in Chicago
>> Folks,
>>  At the moment we have a plan to organize a Bar BOF during IETF-69 to be possibly sponsored by us.
>>  To help us organize this event better, it would be nice if you send me and Suresh a note on your possible attendance. 
>>  Also, the meeting will be totally devoted to technical discussions and not to process discussions. If you can make a technical presentation on the problem and/or solution efforts, again, send me and Suresh a note.
>>  See you in Chicago.
>> Behcet
>> _______________________________________________
>> multimob mailing list
>> multimob@ietf.org
>> https://www1.ietf.org/mailman/listinfo/multimob
> ------------------------------------------------------------------------
> _______________________________________________
> multimob mailing list
> multimob@ietf.org
> https://www1.ietf.org/mailman/listinfo/multimob

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