Re: [mpls] Today's MPLS Open DT meeting cancelled

[Kireeti Kompella <[e-mail]>]

Good points.  See inline for more.

> On Oct 27, 2021, at 08:03, Loa Andersson <[e-mail]> wrote:
> 
> Kireeti,
> 
> Sorry for late response.
> 
> One reason why we setup the agenda as we did for last week (1) requrements and (2 )PSD Directive (if time allows), was that we wanted to the requirements first. Then the discussion on the requirements disappeared it was natural to cancel the meeting.

That makes sense, but we’ve had many months of discussion without the requirements ...

> There are also a few question that I wanted to think about before going ahead with the PSD directive.
> 
> First, the design directive should be a guideline the keeps solutions within a sound architectural boundary. Your text seem to be describing one particulate solution.
> 
> We  should not confuse a design directive with the specification. For the design directive is enough if we say "you can't place PSD that belongs to more than one FA/NF afteer the label with the BoS bit set".

Fair point.  I can rewrite this to be more neutral, or provide input.

Specifically, I will update the text in Backward Compatibility of https://trac.ietf.org/trac/mpls/wiki/encap-rev2 <https://trac.ietf.org/trac/mpls/wiki/encap-rev2> to be solution-neutral.

> The rest is specification and should go into ID/RFC.
> 
> Second, we should not anticipate wg consensus or actually specifications. There are currently more than one proposal, on for example how the indicators should work.
> 
> For example the FAI proposal works with one flag field, and let the implementation figure out what is in the PSD. The NFI proposal is different, and I not entirely clear how it works. I think it is one flag field for actions/function that generate ISD and NoD, and two flag fields (end-to-end and hop-by-hop) for actions/functions that generate PSD.

I think it’s architecturally more sound to have the PSD be self-describing, independent of the details of the solution (FAI or otherwise).  But point taken.

> Your design directive seems to anticipate that we will go with the FAI proposal, but we need to wait to take that decision.

Not really, although it may seem so.  It’s easier for me to work with concrete examples, but once I have that, I can generalize.

:k

> The design directive don't need that decision "don't place more than one set of PSD after the BoS" is independent of how the PSD is generated.
> 
> /Loa
> 
> 
> On 21/10/2021 16:23, Kireeti Kompella wrote:
>> Agree we should wait for Matthew on the requirements discussion, but we can still have the meeting today and talk about the PSD Directive.  I’m ready.
>>> On Oct 21, 2021, at 06:52, Loa Andersson <[e-mail]> wrote:
>>> 
>>> Folks,
>>> 
>>> We have just learned that Matthew can't make today's meeting. In a short consultation with the other chairs we agree that we don't want to take the requirement discussion without Matthew. We therefore decided to postpone the meeting one week.
>>> 
>>> /Loa
>>> -- 
>>> 
>>> Loa Andersson                        email: [e-mail]
>>> Senior MPLS Expert                          [e-mail]
>>> Bronze Dragon Consulting             phone: [phone]
>>> 
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> 
> -- 
> 
> Loa Andersson                        email: [e-mail]
> Senior MPLS Expert                          [e-mail]
> Bronze Dragon Consulting             phone: [phone]