RE: LIN6 i-d for multihoming and mobility support

[Fumio Teraoka <tera@ics.keio.ac.jp>]

Hi Marcelo,

Sorry for very late response.

- MA location: From operation viewpoint, the primary MA will be
  placed in the multihomed site and some secondary MAs will be
  placed in ISPs.

- Latency due to query to MA: The MA is accessed only when a node
  starts communication. This would be insignificant.

- MA for multihoming: It would be unnecessary only to support
  multihoming. However, LIN6 aims to solve not only multihoming
  but also mobility and other issues. The MA makes the Internet
  more flexible.

- We will revise Section 8 of our draft.

Regards,

Fumio Teraoka

At 04/01/04 16:17 -0300, marcelo bagnulo wrote:
>Hi Fumio,
>
>Some comments about this draft.
>
>My main concern about this proposal is about the Mapping Agent
>
>The mapping agent becomes a critical part since it is required to establish
>the communication, so in a multi-homed environment, where do you place it?
>do you place it in the multihomed site or in the isps? what happens if the
>path to the MA is down? i guess that since one of the goals of multihoming
>is the provision of a more resilient network, the inclusion of an additional
>critical device must be very well justified and the potential failures of
>such device must be studied in depth
>
>Besides, the usage of a mapping agent introduces additional latency and
>traffic since, if i understood it correctly, several new round trips are
>required i.e. a query to the MA from the initiator and a reverse DNS query
>and a direct DNS query and a MA query from the receiver is also required.
>These are a lot of additional packets and time required to initiate the
>communication
>
>Finally, i really don't understand why the mapping agent is needed in the
>multi-homed environment. I mean, i do understand that the MA is needed for
>mobility, but i think it is not needed for multihoming. In the noid
>proposal, the mechanism is similar (i think) but only the dns is used. This
>is good because you don't add an additional critical device and you reduce
>the packet exchanges (you don't have to query the MA)
>
>Additionally, there are multiple issues that are not addressed in the draft
>and that IMHO it would be important to understand how they can be addressed
>when using LIN6 like ingress filtering (you claim that this is not an issue
>but i disagree), address selection for initial contact (especially source
>address selection and how is this compatible with the ingress filtering
>solution that you are planning to use), failure detection (how do you know
>that you have to change the address that it is being used, and how do you
>know if you have to change the destination or the source address)
>IMHO all this problems have to be addressed in order to obtain a complete
>multihoming solution and an analysis about how LIN6 is compatible with
>proposed solutions for these issues would be interesting.
>Additionally, i think it would be interesting to include a descrition of how
>lin6 can cope with the threats described in the threats draft. I mean, lin6
>introduces the MA which is susceptible to be attacked. In the security
>section, it is claimed that this solution is not less secure than MIPv6, but
>no comments are included for the multi-homing environment where no MIPv6 is
>used.
>
>Regards, marcelo
>
>> -----Mensaje original-----
>> De: owner-multi6@ops.ietf.org [mailto:owner-multi6@ops.ietf.org]En
>> nombre de Fumio Teraoka
>> Enviado el: martes, 30 de diciembre de 2003 10:25
>> Para: multi6@ops.ietf.org
>> Asunto: LIN6 i-d for multihoming and mobility support
>>
>>
>> Hi all,
>>
>> I have just submitted draft-teraoka-multi6-lin6-00.txt that describes
>> multihoming and mobility support based on LIN6. Sec.8 discusses
>> the features of LIN6 based on RFC3582.
>>
>> The draft is available from the following URL:
>>
>> http://www.tera.ics.keio.ac.jp/person/tera/multi6/draft-teraoka-mu
>lti6-lin6-00.txt
>
>Comments are welcome.
>
>Fumio Teraoka