Subject: [BEHAVE] Discussion on draft-ietf-behave-v6v4-framework-00

From: Hui Deng <[email-masked]>
Date: Thu, 23 Jul 2009 22:14:28 +0800

Hello, all

People here asked me to propose the text to this draft.
I read through the draft, but feel that I need some discussion before
move forward.

China Mobile proposed categorization of scenarios to 3GPP SA2 which will
be discussed in the next meeting.  I write down the link of our last document
http://www.3gpp.org/ftp/tsg_sa/WG2_Arch/TSGS2_74_Sophia_Antipolis/Docs/
you could download S2-094503 document. (this is not yet an accepted document)

Firstly I feel that this draft's scenario is kind of orthogonal with
we proposed in 3GPP.
we have defined IPv6 into four types for a host:
1) application; 2) Stack; 3) Address, 4) Routing.
Current framework draft define IPv6-only is kind of consider (2,3,4 only) case,
But I personally feel translator could happen in more cases like 2
only , 3 only and 4 only
and several other cases.

Secondly, I guess the working group already concensused about
IPv4/IPv6 network/internet.
But for me I really have the diffculty to tell the difference between
IPv6 network and IPv6 Internet.
I guess NAT66 hasn't been accepted by the IETF. Does IPv4
network/Internet will be differentiated
by private and Public IPv4 address? Honestly, as a newbie of this wg,
I am not clear on this.

Thirdly, terminology for IPv4-only and IPv6-only is different from the
3gpp document, 3GPP document
has more deep defined scenarios.

Hope I could receive more comment, and know how to do next.

thanks for your comments.

-Hui

.

---

From: "Dan Wing" <[email-masked]>
Date: Thu, 23 Jul 2009 10:32:44 -0700

> -----Original Message-----
> From: [email-masked] 
> [mailto:[email-masked]] On Behalf Of Hui Deng
> Sent: Thursday, July 23, 2009 7:14 AM
> To: [email-masked]
> Subject: [BEHAVE] Discussion on draft-ietf-behave-v6v4-framework-00
> 
> Hello, all
> 

BEHAVE's categories, which are the 4 scenarios in our charter
(soon to be 6, assuming our charter update is approved), are based
primarily on draft-arkko-townsley-coexistence-00.txt and
Mark Townsley's presentation at the October 2008 interim
meeting in Montreal.  Minutes and presentations from that
meeting are here:
http://trac.tools.ietf.org/area/int/trac/wiki/v4v6interim

> only , 3 only and 4 only and several other cases.

Yes, a translation function could occur anywhere in the network -- 
including inside the host.  The IETF has two existing RFCs which
describe a function where software inside the host does translation,
BIA (RFC3338, published 2002) and BIS (RFC2767, published 2000).

One of BEHAVE's significant guiding principles for our 6/4 translation
work is to not modify the hosts.  This is a principle because we don't
have time -- we are exhausting IPv4 addresses in a few years and it
would take more years to standardize new  functionality in hosts, have
vendors implement that new  functionality (Apple, Microsoft, various
Unix distributions,  printers, etc.), and so on.  So, we have been
concentrating on  solutions that describe a *function* (such as
translation) that can  be placed in the network without requiring the
host's software to be  upgraded or replaced. However, that same
*function* (such as  translation) can be placed in a host, and do the
same thing.  There  are side-effects of either choice -- operational
complexity, ease of  migration for applications, and so on.  Over
time, that function --  or portions of it -- may migrate into hosts.

Multiple translation between address families (IPv4 to IPv6 to IPv4)
is also something we want to avoid because it increases complexity of
the network (as a whole) and makes troubleshooting more difficult.
Alain Durand had proposed doing multiple translation, nicknamed
NAT464, but as far as I know he has abandoned that effort,
http://tools.ietf.org/html/draft-durand-v6ops-natv4v6v4-01.  You might
discuss with him the difficulties of multiple translation.  It might
be possible that the in-host translation, which you seem to prefer to
support legacy IPv4 applications, could avoid the difficulties of
multiple translation.

> IPv4/IPv6 network/internet.

Yes.  That consensus took us about 5 hours at the Montreal 
interim meeting last October.

> IPv6 network and IPv6 Internet.

"a network" is a network under one organization's control.  For
example, a University's network; an Internet service provider's
network and its subscribers; an enterprise's network.  "Internet"
is the Internet.

> I guess NAT66 hasn't been accepted by the IETF.

Yes, so far NAT66 has not been accepted.  At this point in time
it remains an individual draft.

> Does IPv4 network/Internet will be differentiated
> by private and Public IPv4 address?

No.  "An IPv4 network" could have public IPv4 addresses; for example,
that is how almost all Internet service providers operate today --
they give their subscribers publicly-routable IPv4 addresses.  But
it can also be a network that uses private IPv4 addresses; for 
example, many enterprises use a NAT (for various reasons) and 
provide their employees computers with private IPv4 addresses.

> Honestly, as a newbie of this wg,
> I am not clear on this.
> 
> 3gpp document, 3GPP document has more deep defined scenarios.

I skimmed the 3GPP document at
http://www.3gpp.org/ftp/tsg_sa/WG2_Arch/TSGS2_74_Sophia_Antipolis/Docs/S2-0945
03.zip.  Is that the document with more deeply defined scenarios?  It lists 26
scenarios, yet doesn't consider applications running on a tethered PC.  4 of
the scenarios are listed as high-priority (to solve first), and all 4 of those
scenarios have application programs running IPv4 that are running on a
dual-stack handset or IPv6-handset, and connected to a dual-stack or IPv6-only
3GPP network.

-d

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

---

From: Dave Thaler <[email-masked]>
Date: Thu, 23 Jul 2009 17:53:06 +0000

To add to what Dan said...

> BIA (RFC3338, published 2002) and BIS (RFC2767, published 2000).

Actually three.  Don't forget v4-mapped sockets (RFC3493), which is
the one that's actually widely deployed.

> work is to not modify the hosts.

To expand on this, the principle is to not _require_ modifying the
hosts in order to get communication to work.  Working _better_
somehow (more efficient, more secure, whatever) if hosts are modified
is still ok.  Hence in my view translation within the host is still
interesting, and I gave an overview of this topic during the interim
meeting.

-Dave

---

From: "Dan Wing" <[email-masked]>
Date: Thu, 23 Jul 2009 11:06:20 -0700

> From: Dave Thaler [mailto:[email-masked]] 
> Sent: Thursday, July 23, 2009 10:53 AM
> To: 'Hui Deng'
> Cc: Dan Wing; [email-masked]
> Subject: RE: [BEHAVE] Discussion on 
> draft-ietf-behave-v6v4-framework-00
> 

Yes, but that works differently from what, I think, 3GPP is 
concentrating on, which are IPv4 applications they don't want to
change at all.  RFC3493 requires the application make the
new API calls.

> is still ok. 

Good point.  And the DNS64 document describes how DNSSEC validation
can be accomplished in the network but also describes how DNSSEC
validation can be accomplished in the host, too, but would require
the host be "translation-aware".  That awareness could be BIA, BIS,
or just a 'bump in host's the DNS library' to create its own 
synthetic AAAA.

> Hence in my view translation within the host is still

-d

---

From: Hui Deng <[email-masked]>
Date: Sun, 26 Jul 2009 04:35:14 +0800

excuse me for late reply
snip and reply with [Hui]

> http://trac.tools.ietf.org/area/int/trac/wiki/v4v6interim
[Hui] Thanks.

>> only , 3 only and 4 only and several other cases.
[Hui] firstly, my comment hasn't got reply, let me reiterate.
IPv6 onlycould be :1) application; 2) Stack; 3) Address, 4) Routing.
Current framework draft define IPv6-only is kind of consider (1,2,3,4
only) case,
But I personally feel translation could happen in more cases like 2
only , or3 only, or 4 only, or several other cases. the framework like
(1,2,3,4 only)
in my experience network, I haven't see any node. Maybe people could
point out here
where I can find those type of the host.

> time, that function --  or portions of it -- may migrate into hosts.
[Hui] I feel it will be largely different if we put the network into the host.

> support legacy IPv4 applications, could avoid the difficulties of
[Hui] We did analyzation of that draft, will explain it during the presentation.

> interim meeting last October.
[Hui] I personally expect that the draft is easily readable for newbie like me,
other than concensus people only.

> network and its subscribers; an enterprise's network.  "Internet"
[Hui] could you let me know what and where is the border between the
network and Internet.
for example, there are lots of IDC server inside the operator, does
that belong to network or Internet?

> provide their employees computers with private IPv4 addresses.
[Hui] if an IPv4 network could have public Ipv4 address, so
what and where is the border between network and Internet.

> dual-stack handset or IPv6-handset, and connected to a dual-stack or IPv6-only
[Hui] could u kind help to elaborate the difference between tethered
PC and mobile terminal or notebook?

thanks again

-Hui