Subject: (ngtrans) I-D ACTION:draft-kahng-ngtrans-hdsma-00.txt

From: [email-masked]
Date: Tue, 30 Oct 2001 07:14:05 -0500

A New Internet-Draft is available from the on-line Internet-Drafts directories.

	Title		: Requirements for 4to6 mobility transition using 
                          Hierarchical Mobility Agent
	Author(s)	: H. Kahng
	Filename	: draft-kahng-ngtrans-hdsma-00.txt
	Pages		: 11
	Date		: 29-Oct-01
	
This document specifies the requirements for MIPv4/MIPv6 transition. 
Researches  on  the  IPv4  to  IPv6,  or  IPv6  to  IPv4,  transition 
mechanisms are actively being conducted. These transition mechanisms 
assume that hosts are attached to the network statically. Currently, 
developments of communication mechanisms are developed individually 
and differently. This means that the effects of considering mobile 
node (MN) roaming in IPv4/IPv6 transition networks have not been 
investigated. Therefore, this document proposes the requirements and 
analysis of different routing architecture of MIPv4/MIPv6 transition 
network.

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---

From: Pekka Savola <[email-masked]>
Date: Wed, 31 Oct 2001 15:09:06 +0200 (EET)

> analysis of different routing architecture of MIPv4/MIPv6 transition 

I don't really understand the complexity of the architecture, but then
again, I didn't dig too deeply into it.

Should we limit the scope of supported configurations in some way?  E.g. 
assume that:

- if foreign network is IPv6-only, MIPv4 MN's need not work there  
- if foreign network is IPv4-only, MIPv6 MN's need not work there
- if foreign network is dual-stack, MIPv4/6 MN's would work there (MIPv4
would also require FA, but that's an operational concern), but home 
network would have to be dual-stack as long as there is one MIPv4/6 MN,
respectively.
- if MN is IPv6-only, Home Agent is reachable without translation via IPv6 
(tunneling ok)
- if MN is IPv4-only, Home Agent is reachable without translation via 
IPv4 (also, tunneling ok)

Also, there is:

--8<--
3.4 Requirements for DSFA 
    
   In MIPv6 protocol, there is no foreign agent, but in order to provide 
   MIP handoff regional entity is needed within the foreign network. 
   Therefore, like MIPv4's foreign agent, DSFA is required in each 
   subnet. DSFA has to implement MIPv4's foreign agent and MIPv6 
   router's action, and has to be able to recognize IPv4 and IPv6 
   packets and process them. And also due to the problem occurs during 
   transition of routing from one version to another, this document 
   separately describes DSFA as BDSFA and IDSFA.  
--8<--

Hopefully this doesn't try to suggest that every IPv6 router must also
implement MIPv4 FA code ('DSFA is required in each subnet')?

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords

---

From: "Shiao-Li Charles Tsao" <[email-masked]>
Date: Thu, 1 Nov 2001 09:45:27 +0800

Hello,

Please see my comments below ...

----- Original Message -----
From: "Pekka Savola" <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, October 31, 2001 9:09 PM
Subject: (ngtrans) Re: I-D ACTION:draft-kahng-ngtrans-hdsma-00.txt

> IPv4 (also, tunneling ok)

Maybe we can classified MN into IPv4-only, IPv6-only, dual stack v4 (MN is
dual stack and registers a global unique IPv4 address), dual stack v6 (dual
stack with an IPv6 address), and dual stack v4/v6(dual stack with two
addresses). Foreign network can be IPv6-only, IPv4-only and dual stack. Home
network needs to support IP version of MNs, of course. Then, we can get 12
combinations below.

1. MNv4 -> FNv4 (OK)
2. MNv4 -> FNv6 (No)
3. MNv4 -> DS (OK) ... if the foreign network has a FAv4

4. MNv6 -> FNv4 (No)
5. MNv6 -> FNv6 (OK)
6. MNv6 -> DS (OK)

7. DSv4 -> FNv4 (OK)
8. DSv4 -> FNv6 (OK)
9. DSv4 -> DS (OK) ... if the foreign network has a FAv4

10. DSv6 -> FNv4 (OK)
11. DSv6 -> FNv6 (OK)
12. DSv6 -> DS (OK)

As for MN has two address (IPv4, IPv6), basically it can be handled by MIPv4
and MIPv6 separately.

Charles Tsao