Subject: [BEHAVE] Proposed text and comments for framework for IPv4/IPv6 translation

From: bo zhou <[email-masked]>
Date: Mon, 24 Aug 2009 14:00:01 +0800

Hi Fred and others authors of framework for IPv4/IPv6 translation

We have some texts and comments for this draft. Originally, we tried to
propose our comments and discuss them inside last Wed's interim meeting,
Unfortunately, the shortage of time caused we have no time to address them.
Hence, we pointed them out here.

1)  We need more clear IP family host definitions
Inside the draft, existing “IPv6-only” and “IPv4-only” definitions are
targeting to IP host capabilities, but there are unclear descriptions of
“application instances”. Hence we propose the  IP family host shall be
defined combining with four aspects:
a. the application type installed on the host,
b.the IP family stack supported by a host
c.the IP family routing assigned by a network
d.available IP family connectivity
According to the above principles, following IP family host definitions are
suggested to replace current “IPv6-only” and “IPv4-only” definitions and
propose a new definition for supplement:
IPv4 only host comprises an IPv4 enabled end system stack plus routing in
the network, IPv4 applications installed on the host. It implies two
application instances with installed IPv4 applications are capable of
communication using IPv4, but not IPv6 ……
IPv6 only host comprises an IPv6 enabled end system stack plus routing in
the network, IPv6 applications installed on the host. It implies two
application instances with installed IPv6 applications are capable of
communication using IPv6, but not IPv4 ……
IPv4-inherited IPv6 host comprises an IPv4/IPv6 enabled end system
dual-stack plus IPv6 routing in the network, IPv4/IPv6 applications
installed on the host. It implies two application instances with installed
IPv4/IPv6 applications are capable of communication using IPv6 – they have
IPv4/IPv6 dual-stack, network support including routing in IPv6, IPv4/IPv6
applications can communicate with IPv4/IPv6 hosts respectively.
Furthermore, the “An IPv6 network” are proposed to redefined as: A specific
network that has IPv6-only and IPv4-inherited IPv6 implementation.

2）How to differentiate IPv6 network & IPv6 Internet
The difference between IPv4 network and IPv4 Internet could be identified by
CGN (NAT) functionalities. However, there are no CGN(NAT) functionalities
defined in IPv6 world. It’s difficult to differentiate IPv6 network and
Internet. Hence, we suggest to re-define the IPv6 Internet in the framework
draft based on network scale size, as follows: IPv6 Internet means a global
system of interconnected IPv6 networks, including enterprise’s IPv6 networks
and ISP’s IPv6 networks.
Otherwise, we have to introduce a new NAT equipment with NAT66
functionalities to differentiate IPv6 network & IPv6 Internet.

3) Other comments related to the contexts
Comments for 3.1.1 and 3.2.2 about stateful translation statements:
For stateful translation, the draft has mentioned “the stateful translation
only support IPv6 initiated communication”. But NAT-PT could support both
directional communication without this limitation. Hence, we suggest to
remove this descriptions or point out it is only targeting to NAT64
Comments for 3.3 about ALG descriptions:
It only list the demand for FTP ALG. But there should be support any kind of
applications in which IP address is concluded in payload, such as SIP, RTSP.
Hence, we suggest to extend ALG scope avoid reader’s misunderstanding.

Hope all these are meaningful.

Regards,

Bo Zhou
China Mobile

---

From: liu dapeng <[email-masked]>
Date: Sun, 30 Aug 2009 01:58:01 +0800

> defined combining with four aspects:

It seems that it is the time that we should investigate what is the
more clear and precise definition of IPv6-only  and IPv4-only host.

---

From: bo zhou <[email-masked]>
Date: Sun, 30 Aug 2009 02:54:06 +0800

Agreed with Liu.
Furthermore, as I said before, shall we introduce NAT66 to differentiate
IPv6 network from IPv6 Internet as well?

Regards,

Bo Zhou

2009/8/30 liu dapeng <[email-masked]>

-- 
Regards,

Bo Zhou
China Mobile

---

From: Xing Li <[email-masked]>
Date: Mon, 31 Aug 2009 15:28:33 +0800

Thanks for the comments.

(1) Personally, I think the following definition is clear.

  IPv6-only:  An IPv6-only implementation, in this context, comprises
      an IPv6 enabled end system stack plus routing in the network.  It
      implies that two application instances are capable of
      communicating using IPv6, but not IPv4 - they have an IPv6 stack,
      addresses, and network support including routing in IPv6, but some
      element is missing that prevents communication with IPv4 hosts.

However, if the consensus is to add the discussion on application 
instances, I am happy to add the words.

(2) Please see the Sec. 1.2, the border between an IPvx network and the 
IPvx Internet is not defined by NAT.

(3) Other comments are inline.

Regards,

xing

bo zhou 写道:
> We have some texts and comments for this draft. Originally, we tried 
> to propose our comments and discuss them inside last Wed's interim 
> meeting, Unfortunately, the shortage of time caused we have no time to 
> address them. Hence, we pointed them out here.
>  
> targeting to IP host capabilities, but there are unclear descriptions 
> of “application instances”. Hence we propose the  IP family host shall 
> be defined combining with four aspects:
> According to the above principles, following IP family host 
> definitions are suggested to replace current “IPv6-only” and 
> “IPv4-only” definitions and propose a new definition for supplement:
> IPv4 only host comprises an IPv4 enabled end system stack plus routing 
> in the network, IPv4 applications installed on the host. It implies 
> two application instances with installed IPv4 applications are capable 
> of communication using IPv4, but not IPv6 ……
> IPv6 only host comprises an IPv6 enabled end system stack plus routing 
> in the network, IPv6 applications installed on the host. It implies 
> two application instances with installed IPv6 applications are capable 
> of communication using IPv6, but not IPv4 ……
> installed on the host. It implies two application instances with 
> installed IPv4/IPv6 applications are capable of communication using 
> IPv6 – they have IPv4/IPv6 dual-stack, network support including 
> routing in IPv6, IPv4/IPv6 applications can communicate with IPv4/IPv6 
> hosts respectively.
> Furthermore, the “An IPv6 network” are proposed to redefined as: A 
> specific network that has IPv6-only and IPv4-inherited IPv6 
> implementation.
>  
> The difference between IPv4 network and IPv4 Internet could be 
> identified by CGN (NAT) functionalities. However, there are no 
> CGN(NAT) functionalities defined in IPv6 world. It’s difficult to 
> differentiate IPv6 network and Internet. Hence, we suggest to 
> re-define the IPv6 Internet in the framework draft based on network 
> scale size, as follows: IPv6 Internet means a global system of 
> interconnected IPv6 networks, including enterprise’s IPv6 networks and 
> ISP’s IPv6 networks.
> For stateful translation, the draft has mentioned “the stateful 
> translation only support IPv6 initiated communication”. But NAT-PT 
> could support both directional communication without this limitation. 
> Hence, we suggest to remove this descriptions or point out it is only 
> targeting to NAT64

NAT-PT was deprecated by RFC 4966.

> It only list the demand for FTP ALG. But there should be support any 
> kind of applications in which IP address is concluded in payload, such 
> as SIP, RTSP. Hence, we suggest to extend ALG scope avoid reader’s 
> misunderstanding.

Yes, agree.

> ------------------------------------------------------------------------
>
> _______________________________________________
> Behave mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/behave
>

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From: bo zhou <[email-masked]>
Date: Mon, 31 Aug 2009 21:51:28 +0800

Thank you for your reply.
Reply inline.

Regards,

Bo Zhou

> instances, I am happy to add the words.
[bo] Yes, we want to introduce the application type to make the definition
more clearly.

> IPvx Internet is not defined by NAT.
[bo] Sorry, I cannot find any words in Sec.1.2 to define the difference
between network and Internet.

> [bo] Yes, we knew NAT-PT was deprecated by RFC 4966. However, the comments
> we pointed out is focus on stateful translation's limitation. We think "the
> stateful translation only support IPv6 initiated communication" is only
> related to NAT64. It is hard to say "stateful translation can only support
> IPv6 initiated communication" because "NAT64 can only do it". We agreed
> NAT64 is one of significant stateful translation, but we do not agree it
> represents all behaviours of stateful translation.
> [bo]About the ALG issue, we should state "all IP packet payload included IP
> address need do ALG".

>> According to the above principles, following IP family host definitions
>> are suggested to replace current “IPv6-only” and “IPv4-only” definitions and
>> specific network that has IPv6-only and IPv4-inherited IPv6 implementation.
>> The difference between IPv4 network and IPv4 Internet could be identified
>> by CGN (NAT) functionalities. However, there are no CGN(NAT) functionalities
>> translation only support IPv6 initiated communication”. But NAT-PT could
>> support both directional communication without this limitation. Hence, we
>> suggest to remove this descriptions or point out it is only targeting to
>> NAT64
>>
>
>> It only list the demand for FTP ALG. But there should be support any kind
>> of applications in which IP address is concluded in payload, such as SIP,
>> RTSP. Hence, we suggest to extend ALG scope avoid reader’s misunderstanding.
>>
>
> Yes, agree.
>

-- 
Regards,

Bo Zhou
China Mobile