Subject: [homenet] Alvaro Retana's Discuss on draft-ietf-homenet-babel-profile-06: (with DISCUSS and COMMENT)

From: Alvaro Retana <[email-masked]>
Date: Wed, 09 May 2018 09:29:30 -0700

Alvaro Retana has entered the following ballot position for
draft-ietf-homenet-babel-profile-06: Discuss

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----------------------------------------------------------------------
DISCUSS:
----------------------------------------------------------------------

I would like to DISCUSS about the Intended Status of this document -- with the
Chairs and AD.

I have to confess that I haven't been following the homenet WG as closely as I
probably should have.  Hopefully that means that the topic below has been
discussed and documented already, making this DISCUSS easy to resolve.

Back in 2015, the then-Chairs and the AD posted a note titled "Routing Design
Team outcome and next steps"[1]; in it, they declared "rough consensus that
Babel[*] shall be the “mandatory to implement” routing protocol for Homenet
routers, albeit only on an Experimental basis at this time...we solicit
Experimental Internet Drafts to document Homenet-specific profiles of any
applicable routing solution and to report results of any relevant
experimentation and implementation.  We expect that this decision will be
revisited in a future Standards Track document based on specifications and
running code available at that time."

My interpretation of the above text is that Babel is MTI, but that the work
(documents) will be Experimental...and that this decision could change in the
future (most likely towards confirming and moving to the Standards Track). 
This document was originally adopted as Experimental.  I didn't find an
explicit discussion on the list about changing that original overall direction,
nor another declaration by the Chairs/AD.  I did find find a thread in which
one of the Chairs (Barbara) asked about the status for this document (and this
document only)[2]; the initial question was framed around the references being
Standards Track documents (HNCP and rfc6126bis) -- just one answer came back
(from the author of this document)...

I'm treating this point as a DISCUSS because I think that the WG consensus may
have not been determined to change the original declaration from the Chairs/AD
(from 2015).  In my interpretation of that original declaration, moving Babel
to the Standards Track means a recognition that it will be *the* protocol going
forward (which changes that initial "only on an Experimental basis at this
time" phrase), is something that should be discussed explicitly, and not just
in light of this one document.  That is the part that I haven't seen.

I note that in the conclusion of the thread about the status of this document
[3] Barbara does include reasoning that may result in changing the original
declaration (as does the Shepherd writeup), for example: "there exist multiple,
interoperable implementations" and "no drafts proposing other homenet routing
protocol profiles have been submitted"...but those points don't seem to have
been considered/discussed by the WG (they were not in the original message and
I didn't find another thread -- I also looked at the minutes of the last couple
of IETF meetings).

To be clear, I have no objection with Babel being used in homenet applications,
or with it being the Standard protocol.  My point here is that it is not clear
to me that the WG explicitly reached consensus to change the declaration from
the Chairs/AD.  I will be happy to clear this DISCUSS when the Chairs/AD point
me to the discussion that I missed, or simply tell me that the declaration from
2015 is no longer valid and that the WG knows, or that they believe that the
thread discussing this document is enough to call consensus...or something to
that effect.

[1] https://mailarchive.ietf.org/arch/msg/homenet/kiI7pIYfpgT2Qrfx1VBAwng7_QY
[2] https://mailarchive.ietf.org/arch/msg/homenet/5L5WYN14gDCamP7qlknJmWkeU5M
[3] https://mailarchive.ietf.org/arch/msg/homenet/35EU8oBr8hunvvSRYUStypZIPVU

----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------

(1) I think that this document walks a fine line when Normatively referring to
Appendix A in rfc6126bis given that it is an informative appendix.  In general,
it does a good job at it -- I do, however, have one nit: "The algorithm
described in Appendix A of RFC 6126bis MAY be used."  I think that changing
that to something non-normative would be good, perhaps something like "Appendix
A provides an example of an algorithm..." or simply s/MAY/may

(2) This reminds me; please use rfc8174 template (for Normative language).

(3) The Non-requirements sections (2.2/3.2) are confusing to me.  Maybe it's
the "negative logic"...

(3.1) What do these non-requirements represent?  Are they requirements that
were considered at some point, but discarded?  Using rfc2119 language adds to
the confusion -- consider describing these non-requirements not using it.

NR2, for example, is worded as a requirement that was considered, and the
rationale explains why not: an "implementation of Babel MAY include support for
other extensions"...this is not a requirement because "with the exception of
source-specific routing, no extensions are required".  Ok.

(3.2) Are implementers to interpret that the converse is true/expected?  In the
case of NR2, is a true interpretation that implementations SHOULD NOT include
support for other extensions?  IOW, while the option of other extensions is not
a requirement, is not having them one?

(3.3) The non-requirements in §3.2 seem a lot more confusing to me:

(3.3.1) NR3 -- The text says that the requirement not considered
(non-requirement) is such that "an HNCP node that receives a DHCPv6 prefix
delegation MAY announce a non-specific IPv6 default route", but the rationale
says that "announcing an additional non-specific route is allowed".  I'm
confused.  Is announcing the additional route ok, or not?  Is it ok to assume
that optionally advertising the additional route is ok?  If it's allowed, then
why is this a non-requirement?

(3.3.2) For NR4, is the non-requirement, i.e. one that was not considered, that
the source-specific route SHOULD NOT be announced?  This piece is also
confusing to me because the rationale says (at least the way I read it) that it
may be ok to advertise.  It seems to me that the text is saying that in fact
the route SHOULD NOT (or even MUST NOT be announced)...which brings me to the
question: what is the requirement that was not considered?  What am I missing?

---

From: Ted Lemon <[email-masked]>
Date: Wed, 9 May 2018 12:41:32 -0400

On May 9, 2018, at 12:29 PM, Alvaro Retana <[email-masked]> wrote:
> My point here is that it is not clear
> the Chairs/AD.

If you read through section 2 of the document, you will not find a requirement stating that Babel or that this Babel profile is MTI for homenets.  So the document doesn't actually change the status of the consensus that you are talking about.  It does make this Babel profile standard, not experimental.  That makes sense, because this profile is believed to be correct, and has multiple interoperating implementations.  There is no reason for it to be experimental, at least none I'm aware of, and none you've stated.

So while it is an interesting question to ask what the current consensus is on the question you raised, that question is completely orthogonal to this draft's status as standards track.

I would appreciate it if we could avoid reopening that rather contentious discussion at this time.

---

From: "STARK, BARBARA H" <[email-masked]>
Date: Wed, 9 May 2018 22:19:37 +0000

Hi Alvaro,
Thanks for the comments. I agree we need to make sure the community is comfortable with the decision. I've inserted my comments in-line.
Barbara

> I would like to DISCUSS about the Intended Status of this document -- with
> the Chairs and AD.
> 
> My interpretation of the above text is that Babel is MTI, 

<bhs> There is no draft or published RFC that proposes making Babel MTI. The language of the quoted text is a bit odd (a MTI experimental protocol?), which makes it open to interpretation. My interpretation differs from yours. My interpretation was that people actively working to create (experimental) code for homenet stacks needed to implement Babel if they wanted to test out interoperability with other stacks. Those experimental stacks were created. Interoperability was tested. We have running code and a standards-track Babel draft (rfc6126bis) now. I don't believe a WG discussion has the ability to make a protocol MTI in the absence of a published RFC that states it is MTI in some context. No draft exists or has ever been submitted to propose making Babel MTI. 

> but that the work
> one of the Chairs (Barbara) asked about the status for this document (and
> this document only)[2]; the initial question was framed around the references
> being Standards Track documents (HNCP and rfc6126bis) -- just one answer came
> back (from the author of this document)...
>

<bhs> I consider the lack of alternate proposals as implying there are no technical objections to Babel being *the* protocol. It's hard not to be *the* protocol when you're the only protocol. Whether or not the homenet-babel-profile is Standards track, it is *the* protocol in the absence of others. And after 2 years of no other proposal being submitted and multiple Babel profile implementations, I suspect WG participants might push back heavily against adding another protocol. Another protocol would face a serious uphill battle. And this would be true independent of the status attached to the Babel profile. Two years is plenty of time to have submitted a draft. 

But there is nothing in the language of the Babel profile that would preclude submission of another protocol profile. 

> thread discussing this document is enough to call consensus...or something
> to that effect.

I did consider the emails you pointed to as having adequately advised the WG of the proposed change and invited discussion and/or objection. I did also get a private email response pointing to the 2015 decisions you noted but not objecting to the proposed status change. I discussed with Stephen (co-chair) and Terry (AD) who both indicated they were satisfied with the lack of objection to my emails. It is my belief that members of the WG are very, very aware (many still bear deep scars) of the 2015 discussion. They are also aware that the WG has been open to receiving other routing protocol profile proposals for 2 years now, and that none has been received. Several people told me privately they were glad the status was being changed so we could get this over with (and that homenet was already in danger of being obsolete and losing everyone if it couldn't move on). They didn't want to say *anything* on the email thread, for fear that it might actually trigger re-opening the discussion in all it's glory. There is a strong desire not to have that discussion again. I do believe that, given the hyper-awareness of the 2015 discussion, the WG knew what it was agreeing to (or not objecting to). I believe the WG is knowingly saying it wants to move on. Naming and security need solutions, and we need to be working on those.

But if you still think I need to explore this some more with the WG, I will.
Barbara
 
> [1] https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__mailarchive.ietf.org_arch_msg_homenet_kiI7pIYfpgT2Qrfx1VBAwng7-
> 5FQY&d=DwIDaQ&c=LFYZ-o9_HUMeMTSQicvjIg&r=LoGzhC-
> 8sc8SY8Tq4vrfog&m=LS5wCRK83QbSm0A7c-uQ50-sORylXeseG-
> zQI_D8ABU&s=3czWjkOM36nRroRWTFHYjcWEZF_WsTqCHLjLrGBRxmk&e=
> [2] https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__mailarchive.ietf.org_arch_msg_homenet_5L5WYN14gDCamP7qlknJmW
> keU5M&d=DwIDaQ&c=LFYZ-o9_HUMeMTSQicvjIg&r=LoGzhC-
> 8sc8SY8Tq4vrfog&m=LS5wCRK83QbSm0A7c-uQ50-sORylXeseG-
> zQI_D8ABU&s=TntrJlZrFtZU8GHp86i_BfjU5BPtSn5lqHwDVSEHfv0&e=
> [3] https://urldefense.proofpoint.com/v2/url?u=https-
> 3A__mailarchive.ietf.org_arch_msg_homenet_35EU8oBr8hunvvSRYUStypZI
> PVU&d=DwIDaQ&c=LFYZ-o9_HUMeMTSQicvjIg&r=LoGzhC-
> 8sc8SY8Tq4vrfog&m=LS5wCRK83QbSm0A7c-uQ50-sORylXeseG-
> zQI_D8ABU&s=8kr7ZyZhA8zZEKfNDbVouzU-BmWT-t_WOgi7WcZKYkM&e=
> 
>

---

From: Stephen Farrell <[email-masked]>
Date: Thu, 10 May 2018 01:14:40 +0100

On 09/05/18 23:19, STARK, BARBARA H wrote:
> I do believe that, given the hyper-awareness of the 2015 discussion,
> the WG knew what it was agreeing to (or not objecting to). I believe
> the WG is knowingly saying it wants to move on.
FWIW, I concur.

S.

---

From: Terry Manderson <[email-masked]>
Date: Thu, 10 May 2018 03:48:15 +0000

I’ll chime in here reinforce what Barbara says here on the document status.

In light of the evolution of the homenet discussions and particularly in light of the PS work happening for babel (RFC6126) inclusive of the lack of proposed alternatives. I am satisfied with the document moving forward. In the discussions with the chairs I recall being asked if I was ok with PS. I affirmed at that stage. 

I maintain that position – I think PS is the correct status for this draft.

Cheers
Terry

On 10/05/2018, 08:20, "STARK, BARBARA H" <[email-masked]> wrote:

    Hi Alvaro,

---

From: Alvaro Retana <[email-masked]>
Date: Thu, 10 May 2018 06:25:49 -0700

Barbara:

Hi!

Thanks for the response!  This (along with the confirmation from Stephen
and Terry) was all the confirmation I wanted.  I agree with your points and
the rationale.

I’m clearing my DISCUSS.

Thanks!

Alvaro.

On May 9, 2018 at 6:19:56 PM, STARK, BARBARA H ([email-masked]) wrote:

Hi Alvaro,
Thanks for the comments. I agree we need to make sure the community is
comfortable with the decision. I've inserted my comments in-line.
Barbara

> I have to confess that I haven't been following the homenet WG as closely
as
> I

<bhs> There is no draft or published RFC that proposes making Babel MTI.
The language of the quoted text is a bit odd (a MTI experimental
protocol?), which makes it open to interpretation. My interpretation
differs from yours. My interpretation was that people actively working to
create (experimental) code for homenet stacks needed to implement Babel if
they wanted to test out interoperability with other stacks. Those
experimental stacks were created. Interoperability was tested. We have
running code and a standards-track Babel draft (rfc6126bis) now. I don't
believe a WG discussion has the ability to make a protocol MTI in the
absence of a published RFC that states it is MTI in some context. No draft
exists or has ever been submitted to propose making Babel MTI.

> I'm treating this point as a DISCUSS because I think that the WG
consensus
> may

<bhs> I consider the lack of alternate proposals as implying there are no
technical objections to Babel being *the* protocol. It's hard not to be
*the* protocol when you're the only protocol. Whether or not the
homenet-babel-profile is Standards track, it is *the* protocol in the
absence of others. And after 2 years of no other proposal being submitted
and multiple Babel profile implementations, I suspect WG participants might
push back heavily against adding another protocol. Another protocol would
face a serious uphill battle. And this would be true independent of the
status attached to the Babel profile. Two years is plenty of time to have
submitted a draft.

But there is nothing in the language of the Babel profile that would
preclude submission of another protocol profile.

> thread discussing this document is enough to call consensus...or
something

I did consider the emails you pointed to as having adequately advised the
WG of the proposed change and invited discussion and/or objection. I did
also get a private email response pointing to the 2015 decisions you noted
but not objecting to the proposed status change. I discussed with Stephen
(co-chair) and Terry (AD) who both indicated they were satisfied with the
lack of objection to my emails. It is my belief that members of the WG are
very, very aware (many still bear deep scars) of the 2015 discussion. They
are also aware that the WG has been open to receiving other routing
protocol profile proposals for 2 years now, and that none has been
received. Several people told me privately they were glad the status was
being changed so we could get this over with (and that homenet was already
in danger of being obsolete and losing everyone if it couldn't move on).
They didn't want to say *anything* on the email thread, for fear that it
might actually trigger re-opening the discussion in all it's glory. There
is a strong desire not to have that discussion again. I do believe that,
given the hyper-awareness of the 2015 discussion, the WG knew what it was
agreeing to (or not objecting to). I believe the WG is knowingly saying it
wants to move on. Naming and security need solutions, and we need to be
working on those.

But if you still think I need to explore this some more with the WG, I
will.
Barbara

> (3.2) Are implementers to interpret that the converse is true/expected?
In
> the
> support for other extensions? IOW, while the option of other extensions
is
> not
> (3.3.2) For NR4, is the non-requirement, i.e. one that was not
considered,
> that