Subject: RE: (ngtrans) Re: Prior art on IPv6-in-IPv4 tunneling

From: Jung Cyndi-ACJ099 <[email-masked]>
Date: Wed, 9 Oct 2002 13:43:10 -0500

Fred,

I can verify what Brian has said - I was about to say the same thing.

As I recall, a 3Com switch to Lixia's lab was part of getting the project
going.  There are no IPR claims.  At the time, the 6over4 draft had some
language about what to do in case IPv4 multicast was not available, though
that was removed (the thought at the time was that IPv4 multicast would be
widely deployed long before IPv6 would be mature - how different things have
turned out).

When Microsoft Research implemented 6over4, and interoperability was established,
the draft became RFC2529.

Cyndi

-----Original Message-----
From: Brian E Carpenter [mailto:[email-masked]]
Sent: Tuesday, October 08, 2002 11:32 PM
To: Fred L. Templin
Cc: [email-masked]; [email-masked]; lixia
Subject: (ngtrans) Re: Prior art on IPv6-in-IPv4 tunneling

Fred,

I'm not quite sure what point you are making here or why. That work was 
in fact the first implementation of 6over4 - the authors of RFC 2529 were 
in contact with Lixia Zhang and Quang Nguyen. The first publication was 
draft-carpenter-ipng-6over4-00.txt in November 1996, discussed at
the IPNGWG meeting in December 1996. 

I agree that Quang Nguyen's paper was interesting and thought around the
topic. But his code was 6over4 and the prior art for that is from 
November 1996. Both the authors of 6over4 have changed employers since
then, but to the best of my knowledge no IPR claims were made.

Of course the basic idea of tunnelling is older and trivial.

   Brian

"Fred L. Templin" wrote:
> 
> Dear friends,
> 
> It has very recently been brought to my attention that a defining work
> on IPv6-in-IPv4 tunneling exists dating back to Spring 1998 and entitled:
> 
>    "Virtual Ethernet: A New Approach to IPv6 Transition"
> 
> The work was prepared by a UCLA Masters Student named Quang Nguyen
> who was advised by Dr. Lixia Zhang. The document describes the case
> of intra-site tunneling when IPv4 multicast is deployed (as in 6over4)
> but also gives a detailed study of the case in which IPv4 multicast is
> absent (as in isatap).
> 
> Upon examining the document, I realized that concepts presented in
> the isatap specification match up very closely with the prior art so
> I contacted Dr. Zhang to arrange a meeting to discuss the similarities.
> Dr. Zhang and I were able to meet today, and she has requested that an
> acknowledgement to her student and a reference to the document be given
> in the specification. This action will be taken asap in the next isatap
> draft revision.
> 
> The document in question can be found at:
> 
>    http://irl.cs.ucla.edu/vet/report.ps
> 
> I would encourage other v6ops/ngtrans authors to examine this work for
> prior art. For example, the isatap "automatic deprecation" and teredo
> "automatic sunset" functions seem to have existing precedence in this
> work.
> 
> Sincerely,
> 
> Fred Templin
> [email-masked]

---

From: Jung Cyndi-ACJ099 <[email-masked]>
Date: Wed, 9 Oct 2002 13:47:45 -0500

By all means, acknowledge their work.

Cyndi

-----Original Message-----
From: Fred L. Templin [mailto:[email-masked]]
Sent: Wednesday, October 09, 2002 10:04 AM
To: [email-masked]; [email-masked]
Cc: lixia; Brian E Carpenter; Fred L. Templin
Subject: (ngtrans) Re: Prior art on IPv6-in-IPv4 tunneling

Brian,

Please don't get me wrong; I agree with the timeline you've outlined for
6over4 in relation to the work of Quang Nguyen who was advised by Dr. Zhang.
My purpose is in flagging the fact that the Quang Nguyen paper also extends
to the subject of intra-site automatic tunneling when IPv4 multicast is not
available, where 6over4 (RFC 2529) does not. The unicast case represents the
area covered by isatap, and now having seen the Quang Nguyen paper for the
first time it is clear to me that isatap has independently re-created many
aspects of this earlier work.

Since isatap has been represented to the community for over 2yrs with no
reference to the earlier work, I have a due dilligence responsibility to
Quang Nguyen, Dr. Zhang and the community to make this known publicly and
to outline my plans to remedy the shortcoming. At the same time, I am
recommending that any other authors whose works on tunneling post-date
the Quang Nguyen effort review this document for possible overlap with
their work and give proper references if any such overlap exists.

Does this make things clearer?

Fred
[email-masked]