Re: [6lo] draft-ietf-6lo-multicast-registration-08 replacing MLD

[Alvaro Retana <[e-mail]>]

Hi!

Sorry to jump in — consider my comments as a WG participant.

The proposal doesn’t really work for me.  Even if the intent is for
draft-ietf-6lo-multicast-registration to be used only on “non-broadcast IoT
links”, there’s nothing that prevents its use on “regular” links (just like
all the other related enhancements) — which takes us back to what Stig is
asking about: the need for interoperability.

I would prefer it if the “future document” mentioned below is started soon,
and not at some indeterminate time in the future.  Also, it seems to me
that separating the ND and MLD interoperability would be a good thing.  As
an individual, I’m willing to help if needed.

Thanks!

Alvaro.

On September 11, 2022 at 9:56:30 PM, Stig Venaas ([e-mail]) wrote:

Hi Pascal

Yes, that works.

Thanks,
Stig

On Tue, Aug 9, 2022 at 3:30 AM Pascal Thubert (pthubert)
<[e-mail]> wrote:
>
> Hello Stig
>
> The rationale behind a new protocol is, same as all 6lo work, power
efficiency in IoT space. Now, IoT is a precursor to moving more device to
the green side. So your point stands. Either we are specific that in the
target space there is no MLD at all, or we talk interactions between the
two.
>
> IoT devices will typically sleep more than even cats do. They cannot stay
awake at all times just in case they are be polled for a report. They
cannot store much code either. The proposal is a simple extension to
existing code, since the change we're doing here was already done for
classical IPv6 ND with RFC 8505, 8928 and 8929. RFC 8929 typically isolates
the non-broadcast IoT edge from the broadcast backbone. Note that with RFC
8505, IoT devices do not use SNMA so no need for MLD there either.
>
> Now for both ND and MLD, there will be a time of coexistence in the same
link. The documents for ND is already long awaited. My suggestion is that
that a future document covers both, and the current draft is for
non-broadcast IoT links only, no coexistence.
>
> Works?
>
> Pascal
>
>
> > -----Original Message-----
> > From: Stig Venaas <[e-mail]>
> > Sent: lundi 8 août 2022 19:21
> > To: [e-mail]; [e-mail]
> > Cc: Alvaro Retana <[e-mail]>; [e-mail]
> > Subject: draft-ietf-6lo-multicast-registration-08 replacing MLD
> >
> > Hi 6lo and draft authors
> >
> > I have some concerns about this draft replacing MLD for group
> > registration.
> >
> > Having 2 different protocols for the same thing can be problematic.
> > Hosts or routers may need to support both protocols. Is it clear which
> > one should be used in different environments? Is there a chance that
> > both may be used at the same time in a network? In particular, is there
> > a chance that a router may need to simultaneously support both
protocols
> > on an L3 interface? In that case it must be considered how the two
> > protocols interoperate.
> >
> > Also, we have been pushing the use of SSM in the IETF for a very long
> > time, but this draft only supports ASM since only a group address is
> > provided.
> >
> > It would be good to have some more info on the need to replace MLD. I
> > understand there are concerns about packet loss, limited resources etc.
> >
> > Regards,
> > Stig