[DNA] Re: On the BCP documents

[Pekka Nikander <pekka.nikander@nomadiclab.com>]

>> Firstly, we'd like to see the two BCP related drafts,
>>     draft-narayanan-dna-bcp-01.txt
>>     draft-jinchoi-dna-cpl-01.txt
>> to be merged and then adopted as a merged document a
>> WG item.
>
> Kindly tell me why. I looked through both drafts thoroughly
> and see few benefit to merge them.

Well, from a standardisation point of view, it would be nice
if we had a single, nice BCP document.  (Remember, IETF is
mostly about standardisation.)  If I understood correctly
what Greg said, Greg and I think that both drafts represent
nice pieces of work that seem to belong to the BCP space.
Hence, merging them would be good.

A counter point is that if there reasons for having
several documents in the BCP space, e.g., because a single
document would be excessively long, we *can* have several
documents there.  However, even combined, the two documents
are still much less than 100 pages.  Hence, from that point
of view, I don't see a reason why they could not be combined.

Ideally, at least I would like the BCP document to outline
(or specify, or whatever) several procedures that can be
considered BCP.  The applicability of the procedures would
probably depend on what kind of info you get from the link
layer, and on other factors.  For example, if you get reliable
link up and down indications, you may get good enough
results without CPL, using something more simple minded.

Personally, from a deployment point of view, I don't expect
much of the BCP work to be deployed soon.  Some yes, but most
probably any larger deployment will take place together with
the "DNA solution", just to make hosts able to act nicely
independent of whether they enter a network where the
"DNA solution" has been deployed or not.  Most people just
don't update their stack that often.

<snip>

> I agree. BCP work is to present a way (or ways) to perform DNA
> without standard change. I understand that BCP & Solution aim
> the same thing and 'whether standard change is allowed or not'
> is the main, or maybe only, difference between them.

I mostly agree, but, personally, I wish that the BCP document
would also explain more the background, and give more information
in that sense.  It does not need to be all normative text.

<snip>

> The reason I raised the issues about BCP draft is NOT that
> it present incomplete solutions BUT that it contains materials
> that are not part of BCP solutions

Well, we can discuss today if the WG agrees with you.  Personally,
I don't see a reason why the BCP cannot explain background,
and reasons why some things are suggested to be done in a certain
way.  In a way, what we are preparing may not be a typical BCP,
but it does not seem to be a Standard either.  It could be even
just Informational, and maybe the IESG changes it to be so.
On the other hand, the goal is to define the community consensus
on how you could (or should) do DNA in existing networks that
do not implement the forthcoming "DNA solution", and hence I still
think that the BCP status looks like the best one.

Due to the variety of networks, stacks, and implementations,
the situation looks like that there is no single one-size-
fits-all procedure, but you may want to do it differently
depending on your conditions.  Hence, to me, it makes sense
to explain and ponder upon these conditions in the BCP,
even if briefly.  Thus, I don't agree with you that all
that is not "part of BCP solutions" should be removed.
But this is just my personal opinion; the WG decides, not me.

> For example, the draft talks about how a host performs DAD
> after DNA completion. Though I think it would be helpful,
> I don't think that's part of DNA and wish BCP draft focus more
> on how to perform DNA without standard change.

As I explained already above, personally I don't seen any need
for such strict focus.  The documents are not multi-hundred-page
ones, at least not yet.  If they grow that large, then there
may be a point to remove some of the stuff.

> Actually those materials, such as DNA & DAD or DNA or
> bi-directional reachability, concern both BCP & Solution works,
> so I think, for organizational point of view, it would be better
> to present them in a separate draft, not inside BCP.

Again, personally, I don't see why.  The document is not too long.

> Do you still think it's wise for BCP draft to contain those
> materials, such as DNA & DAD?

Personally, yes.

I guess it may be a good idea to discuss this at the f2f meeting
today.

--Pekka