Subject: Re: [mobile-ip] re:draft-ohnishi-mobileip-mbg-00.txt

From: Hiroyuki OHNISHI <[email-masked]>
Date: Thu, 19 Jul 2001 13:11:39 +0900

Hi,

At 17:23 01/07/17 -0500, you wrote:
>Hiroyuki and Yasushi,
>
>In reference to your draft:
>
><http://www.ietf.org/internet-drafts/draft-ohnishi-mobileip-mbg-00.txt>http://www.ietf.org/internet-drafts/draft-ohnishi-mobileip-mbg-00.txt 
>
>
>I have a few questions and comments:
>
>Would the MGBs be similar or perhaps even the same border routers between 
>autonomous systems of 2 ISPs such as two cellular ISPs?

MBGs are located as border routers between ISPs.
But MBGs have Mobile IP functions and they are not same as ordinary border 
routers.

>What signaling protocol are you looking at to distribute the fact that 
>the address ranges are mobile address from the HA to the MGBs: BGP, OSPF, 
>IS-IS or do you feel that this can be done with simple configuration?

In this version of this draft, I assume that the address ranges are set 
with simple configuration.
Because I want to control MBGs and HAs strictly to support stable security 
associations.

But I also recognize the necessity of the distribution techniques.
I am not sure whether the use of routing protocol to distribute the 
address ranges of mobile nodes is appropriate or not.
Is there any comments?

>It seems to me that the conveyance of this information would also 
>constitute an IP roaming agreement. An automatic, routing protocol-based 
>way of setting these up would be of benefit IMO. Furthurmore, I believe 
>some similar work should be done to identify geographical adjacency for 
>handoff purposes.

I also want to know answers of the following questions.
This draft provides a realistic way to achieve route optimization without 
adding any functions to CNs.
And this technique will help ISPs to provide Mobile IP services.

I hope many folks will be interested in this work.
Comments are welcome.

>Question to the chairs and/or ADs:
>
>
>Would this work fall under MIP WG or routing WGs?
>
>Are you planning any follow-up work on this?
>
>The expect that the antagonists to this draft may complain about the 
>number of per-node routes and what this will do to the routing table size. 
>Last time I checked route lookups were pretty fast in most of the newer 
>products - even with fairly large routing tables; nevertheless, I expect 
>there to be some contention on this. Has there been any analysis on this?
>
>Some positive comments I have on this is that it does indeed seem to be a 
>very realistic deployment method for route optimization. I have not heard 
>of any plans to support route optimization on IPv4 hosts by any of the 
>major OS vendors. It makes sense to me to distribute the fact that certain 
>addresses are mobile to portions of the network. I honestly believe that 
>there are other reasons such as location privacy to maintain the mobile 
>bindings in routers as well. I believe that such functions are better left 
>in purpose built machines that handle handle fast lookups on relatively 
>large route tables. Some analysis on this aspect would also be useful?
>
>Another thing I would like to bring up to folks on the list is that even 
>in IPv6, there is no MUST that CN hosts support the binding functions of 
>MIPv6. With this in mind, I expect there will be nodes out there that 
>don't do it. So even in IPv6, the ubiquity of route optimization is still 
>in question. This gives credence to the reasoning for the solution in IPv6 
>as well.
>
>Another thing I would like to point out that the signaling methodology 
>seems quite similar, as far as the MGP querying the HA for the binding, to 
>some the initial work on the GES, 8+8 concepts. You seem to be doing the 
>query without having to changing the IP header or mess with the addressing 
>schemas - a bonus IMHO. The fact that you are using the mobile IP HA 
>instead of something like DNS is also a good idea IMO due to speed and an 
>already overloaded DNS.
>
>It also seems to me that this would allow IPv4 ISPs to offer the service 
>without having to fork-lift all of their clients' host operating systems. 
>A money saving and realistic idea.

>On the analysis questions - are there any papers available which explore 
>these topics you could point us to?
>
>Thanks,
>
>Glenn

Thanks,

Hiroyuki