Subject: [aqm] PIE & CableLabs

From: "Eggert, Lars" <[email-masked]>
Date: Fri, 8 Nov 2013 20:20:44 +0000

Hi,

just as a quick follow-up and maybe clarification to what I said at the meeting, could anyone find out:

(1) If the variant of PIE that CableLabs has settled on has a formal specification?

(2) If yes, if it is accessible to IETF participants?

(3) If yes, if their copyright, IPR and standardization rules let us work with it in the AQM WG like with any other contribution?

And I guess if any of these answers is "no", we'll need to figure out what that means for us in the AQM WG going forward.

Lars

---

From: Greg White <[email-masked]>
Date: Fri, 8 Nov 2013 20:52:08 +0000

Lars,

1) Yes, CableLabs has settled on a formal specification.  It can be found
in Annex M of 
http://www.cablelabs.com/specifications/CM-SP-MULPIv3.1-I01-131029.pdf

2) see above.

3) Probably not directly. We have requested that Cisco update the PIE I-D
to include the updates to the core PIE algorithm made as part of the
CableLabs evaluation. CableLabs will draft an I-D to cover the remaining
gaps between that and what can be found in 1.  I think this achieves what
you are after.  Let me know if not.

-Greg

On 11/8/13, 1:20 PM, "Eggert, Lars" <[email-masked]> wrote:

>(3) If yes, if their copyright, IPR and standardization rules let us work
>with it in the AQM WG like with any other contribution?
>
>And I guess if any of these answers is "no", we'll need to figure out
>what that means for us in the AQM WG going forward.
>
>Lars

---

From: "Eggert, Lars" <[email-masked]>
Date: Fri, 8 Nov 2013 21:22:07 +0000

Hi,

> http://www.cablelabs.com/specifications/CM-SP-MULPIv3.1-I01-131029.pdf

great, thanks Greg!

> you are after.  Let me know if not.

That sounds like pretty good plan.

One remaining question is what will happen if the AQM WG - after adopting the PIE contribution - makes modifications. Is CableLabs prepared to update their specs based on whet we'll do, referring to an eventual IETF RFC rather than maintaining a separate spec? Or will CableLabs also continue work on the spec and we may end up with eventual divergence? (Or will the CableLabs spec of PIE remain frozen at its current version?)

Having asked that, I want to make clear that the working relationship with CableLabs has been good, and it's not that I'm expecting problems here. It's after all - at least at the moment - the same people working on PIE here and there. It's just that I've been involved in cases in the IETF before where things fell through the cracks when two SDOs simultaneously worked on something, and it's messy to create alignment after that has happened. So an explicit agreement about how this will go forward would be good to have.

Thanks,
Lars

---

From: Greg White <[email-masked]>
Date: Fri, 8 Nov 2013 22:42:50 +0000

On 11/8/13, 2:22 PM, "Eggert, Lars" <[email-masked]> wrote:

>One remaining question is what will happen if the AQM WG - after adopting
>the PIE contribution - makes modifications. Is CableLabs prepared to
>update their specs based on whet we'll do, referring to an eventual IETF
>RFC rather than maintaining a separate spec? Or will CableLabs also
>continue work on the spec and we may end up with eventual divergence? (Or
>will the CableLabs spec of PIE remain frozen at its current version?)

We would like convergence as well.  Our intent is that the algorithm can
be tweaked after deployment via software update, but there will of course
be limitations to how much can be changed.  Whether improvements come from
within IETF community or CableLabs community, we'll aim for maintaining
alignment.  That may mean that we'll push back if changes can't be
accommodated in  our networks, or if IPR issues arise.  Assuming that it
is feasible to maintain alignment with an eventual IETF RFC, we would
strongly consider updating our specification to point to it (I think that
would be a good outcome).

>Having asked that, I want to make clear that the working relationship
>with CableLabs has been good, and it's not that I'm expecting problems
>here. It's after all - at least at the moment - the same people working
>on PIE here and there. It's just that I've been involved in cases in the
>IETF before where things fell through the cracks when two SDOs
>simultaneously worked on something, and it's messy to create alignment
>after that has happened. So an explicit agreement about how this will go
>forward would be good to have.
>
>Thanks,
>Lars
>
>