Re: [nvo3] Update on encapsulation design team

[Fabio Maino <[e-mail]>]

I think it will be useful for the design team to articulate clearly and 
motivate those objections, and present it to the WG for formal 
discussion BEFORE starting the new design. That should help consolidate 
the requirements for the design of the new encap.

A separate technical document will help  evaluate in depth the 
objections raised, rather than rely on hundreds of emails and their 
different interpretation.

I think I have seen quite a lot of disagreement around the objection 
themselves.

For example, wrt GPE extensibility the summary reported that

"- GPE is insufficiently extensible. Numerous extensions and options 
have been designed for GUE and Geneve. Note that these have not yet been 
validated by the WG."

That assertion seems to ignore (as it has been pointed out multiple time 
in the mailing list) what has been done with NSH, or other proposed  
encodings for carrying metadata with VXLAN-GPE such as:
https://tools.ietf.org/html/draft-ietf-sfc-nsh-10
https://tools.ietf.org/html/draft-brockners-inband-oam-data

I would like the WG to articulate why, from a technical point of view, 
proper layering can't be used to extend GPE (as recommended by the GPE 
draft itself), as it is certainly possible (and done) in the two drafts 
indicated above.

Same goes for the security objection to GPE.

I'm quite sure the authors of the other two proposals have similar view 
on the objections raised to their proposals.

A separate document, in my opinion, would help understanding what needs 
to be addressed before we start with the new design.


Thanks,
Fabio

On 10/24/16 12:51 PM, Anoop Ghanwani wrote:
> Hi Alia,
>
> Ideally I would rather not go there at all as expressed in the first 
> part of Fabio's note.  Assuming we must go there, having a section 
> that documents why the WG thought we needed a new one would be good 
> enough for me.
>
> Anoop
>
> On Mon, Oct 24, 2016 at 11:46 AM, Alia Atlas <[e-mail] 
> <mailto:[e-mail]>> wrote:
>
>     Hi Anoop,
>
>     On Mon, Oct 24, 2016 at 2:43 PM, Anoop Ghanwani
>     <[e-mail] <mailto:[e-mail]>> wrote:
>
>         Alia,
>
>         I think it will provide an official reference which will be
>         helpful since all the encaps will be around a long time and we
>         can point people to that document when we are asked the
>         question "why did they develop yet another encap?".
>
>
>     So what you are asking for is a section in the overall draft that
>     talks about the motivations and improvements?
>     There's a trade-off of speed and getting a solution done versus
>     doing process work for a theoretical future that won't happen if
>     we don't get the technical work finished.
>
>     Regards,
>     Alia
>
>         Thanks,
>         Anoop
>
>         On Mon, Oct 24, 2016 at 11:30 AM, Alia Atlas
>         <[e-mail] <mailto:[e-mail]>> wrote:
>
>             Anoop & Fabiio,
>
>             On Mon, Oct 24, 2016 at 2:26 PM, Anoop Ghanwani
>             <[e-mail] <mailto:[e-mail]>> wrote:
>
>                 Agree with Fabio (including the suggestion for an
>                 interim deliverable on shortcomings).  If the WG
>                 doesn't agree on the shortcomings, chances are they
>                 may not like the 4th encap.
>
>
>             What do you expect to be different from the summary of
>             technical objections that came out of the last
>             discussion?  Are you looking for more detail?
>             I didn't see disagreement about the accuracy of the
>             technical objections.
>
>             Regards,
>             Alia
>
>                 Anoop
>
>                 On Thu, Oct 20, 2016 at 12:10 PM, Dino Farinacci
>                 <[e-mail] <mailto:[e-mail]>> wrote:
>
>                     I agree with Fabio.
>
>                     Choosing a single encapsulation that is not 1 of
>                     the 3, creates a 4th one that no one wants.
>
>                     And guess what, you make all 3 authors unhappy
>                     where none of them will endorse (or implement) the
>                     4th one.
>
>                     Dino
>
>                     > On Oct 20, 2016, at 12:02 PM, Fabio Maino
>                     <[e-mail] <mailto:[e-mail]>> wrote:
>                     >
>                     > (for full disclosure I'm one of the authors of
>                     VXLAN-GPE)
>                     >
>                     > Matt, Sam, Alia,
>                     > I've expressed multiple times and in multiple
>                     venues my adversity (and the motivations) to set
>                     this group to design yet another encapsulation. I
>                     won't repeat it here once again, but I want to
>                     re-assert that it's still were I stand.
>                     >
>                     > I've seen quite a few people in the mailing list
>                     here expressing similar concerns, but I see that
>                     it has not changed the opinion of the chairs and
>                     the AD on what they believe is the best way to
>                     move forward.
>                     >
>                     > That said, here are my comments to the charter.
>                     >
>                     > I think the design team first goal should be to
>                     clearly articulate the shortcomings of the current
>                     encapsulations proposed to the WG. This should be
>                     the very first deliverable of the design team. The
>                     actual design work should start only once the WG
>                     has reached consensus on that document. Especially
>                     considering that some of the encapsulations
>                     proposed are being deployed, I think articulating
>                     the shortcomings will help to make the best choice
>                     in term of (1) selecting which one will need to be
>                     extended, and (2) designing the actual extensions.
>                     >
>                     > Below are my proposals on how to modify the
>                     wording of the charter.
>                     >
>                     >
>                     >
>                     > On 10/20/16 1:37 AM, Bocci, Matthew (Nokia - GB)
>                     wrote:
>                     >> WG,
>                     >>
>                     >> We would like to give you an update on the
>                     process in the WG for progressing the issue of a
>                     data plane encapsulation. The chairs and Alia
>                     believe that the best way forward is to progress a
>                     single encapsulation format that addresses the
>                     technical concerns raised on the list in the
>                     recent discussions. This would address the clear
>                     overall consensus of the Berlin meeting and list
>                     for a single encapsulation.
>                     >>
>                     >> The strategy should be to take one of the three
>                     existing encapsulations and enhance it to address
>                     these concerns. This would become the standards
>                     track output of the WG. The existing three drafts
>                     (GENEVE, GUE and VXLAN-GPE) should be forwarded to
>                     the IESG as informational after the standards
>                     track draft specifying the single encapsulation.
>                     This provides an opportunity for those
>                     encapsulations to be documented and maintained.
>                     >>
>                     >> The single encapsulation should be viewed as
>                     one that the WG and industry can converge around
>                     for the future.
>                     >>
>                     >> We have created a design team to progress work
>                     on a single encapsulation that can form the basis
>                     or work going forward. The design team members
>                     are: Michael Schmidt, Uri Elzur, Ilango Ganga,
>                     Erik Nordmark, Rajeev Manur, Prankaj Garg. Many
>                     thanks to these individuals for their help.
>                     >>
>                     >> Please see below for a draft charter for the
>                     design team. Please review the charter and send
>                     comments to the list by 2nd November 2016.
>                     >>
>                     >> Regards,
>                     >>
>                     >> Matthew and Sam
>                     >>
>                     >>
>                     >> ====
>                     >> NVO3 Encapsulation Design team 2016
>                     >>
>                     >> Problem Statement
>                     >> The NVO3 WG charter states that it may produce
>                     requirements for network virtualization data
>                     planes based on encapsulation of virtual network
>                     traffic over an IP-based underlay data plane. Such
>                     requirements should consider OAM and security.
>                     Based on these requirements the WG will select,
>                     extend, and/or develop one or more data plane
>                     encapsulation format(s).
>                     >>
>                     >> This has led to drafts describing three
>                     encapsulations being adopted by the working group:
>                     >> - draft-ietf-nvo3-geneve-03
>                     >> - draft-ietf-nvo3-gue-04
>                     >> - draft-ietf-nvo3-vxlan-gpe-02
>                     >>
>                     >> Discussion on the list and in face-to-face
>                     meetings has identified a number of technical
>                     problems with each of these encapsulations.
>                     Furthermore, there was clear consensus at the IETF
>                     meeting in Berlin that it is undesirable for the
>                     working group to progress more than one data plane
>                     encapsulation. Although consensus could not be
>                     reached on the list, the overall consensus was for
>                     a single encapsulation (RFC2418, Section 3.3).
>                     Nonetheless there has been resistance to
>                     converging on a single encapsulation format,
>                     although doing so would provide the best benefit
>                     to the industry.
>                     >
>                     > The portion of the last sentence that follows
>                     the comma ("although doing so would provide the
>                     best benefit to the industry") doesn't seem to be
>                     adding anything to the charter. I'd suggest it
>                     could be removed.
>                     >
>                     >>
>                     >> Design Team Goals
>                     > The design team should clearly articulate in a
>                     draft which are the shortcomings of the proposed
>                     encapsulations, and where they fall short in
>                     addressing the NVO3 architectural requirements.
>                     >
>                     > Once the 'shortcomings' draft has reached
>                     consensus of the WG,
>                     >> The design team should take one of the proposed
>                     encapsulations and enhance it to address the
>                     technical concerns.
>                     >> Backwards compatibility with the chosen
>                     encapsulation and the simple evolution of deployed
>                     networks as well as applicability to all locations
>                     in the NVO3 architecture
>                     > , together with the design goals articulated in
>                     the 'shortcoming' draft,
>                     >
>                     >> are goals. The DT should specifically avoid a
>                     design that is burdensome on hardware
>                     implementations, but should allow future
>                     extensibility. The chosen design should also
>                     operate well with ICMP and in ECMP environments.
>                     If further extensibility is required, then it
>                     should be done in such a manner that it does not
>                     require the consent of an entity outside of the IETF.
>                     >>
>                     >> Timeline
>                     >> The design team should
>                     > first produce the 'shortcomings' draft, get it
>                     adopted by the WG, and then
>                     >
>                     >> produce a first draft describing the proposal
>                     by end of January 2017. Target adoption by the WG
>                     by March 2017 IETF.
>                     >>
>                     > (those two dates may need to be adjusted
>                     accordingly)
>                     >
>                     >
>                     > Thanks,
>                     > Fabio
>                     >
>                     >>
>                     >>
>                     >>
>                     >>
>                     >>
>                     >>
>                     >> _______________________________________________
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>                     >>
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>                     >
>                     >
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