Re: [Roll] multicast & MLD on LLN

On Wed, Oct 15, 2014 at 4:27 PM, Turner, Randy <Randy.Turner@landisgyr.com>
wrote:

> Hi Pascal,
>
> This multicast use-case is similar to the street light group use-case,
> except aimed at the AMI grid network:
>
> There is of course a need to multicast firmware updates to devices in the
> smart grid. In that example (and in other AMR use-cases) all devices in
> the network subscribe to a common multicast address ‹ it¹s really a
> broadcast, if all devices need to be updated at the same time, with the
> same firmware.
>
> Surely you'd want to do OTA updates in a secure fashion?  Does this
highlight
a need for secure multicast?

> Then there is a multicast group scenario where, say, only 500 of 5000
> nodes need to be updated (possibly associated with a geographic region of
> the grid)
>
> THere¹s also a region-oriented multicast group address that could be used
> to send control/management information to a particular set of smart meters
> in the field. For instance if there is problem with a substation
> controlling a particular geographic region of homes, the grid head-end
> systems may elect to send a particular command to this region of home
> meters to adjust their operation in light of upstream grid issues.
>
> There may be some mapping of multicast address to geographic region so
> that meters can use their GPS location to automatically derive what
> multicast address to subscribe to.
>
> Is the GPS position manually configured in the meter?  If so, perhaps
manual
configuration of multicast group address is just marginally more expensive.

It could also be the case that multicast group addresses are named objects.
For example, one could assign DNS names to groups and resolve this to a
AAAA record (just as with unicast addresses) or use DNS-SD to find a
multicast service binding.

-K-

>
> Hope this helps
> Randy
>
>
> On 10/15/14, 4:08 PM, "Carsten Bormann" <cabo@tzi.org> wrote:
>
> >Hi Don,
> >
> >this sounds exactly like a use case our multicasting approach can solve.
> >
> >Two questions:
> >
> >1) Are you using storing or non-storing mode for RPL?
> >
> >2) For the kinds of groups below, was is the likely distribution of group
> >sizes?
> >
> >Grüße, Carsten
> >
> >On 15 Oct 2014, at 18:58, Don Sturek <d.sturek@att.net> wrote:
> >
> >> 4)  From an application point of view, we want to use special
> >>application-defined multicast groups for things like:
> >>        A.    Control a geographic collection of street lights (like all
> >>the ones in an area where there is to be a festival this evening)
> >>        B.    Control a geographically  diverse collection of devices
> >>that are not the entire population (for example, I want a message sent
> >>to all of my pre-pay customers which are mainly focused in some
> >>neighborhoods, less in others)
> >
> >_______________________________________________
> >Roll mailing list
> >Roll@ietf.org
> >https://www.ietf.org/mailman/listinfo/roll
>
>
> P PLEASE CONSIDER OUR ENVIRONMENT BEFORE PRINTING THIS EMAIL.
>
> This e-mail (including any attachments) is confidential and may be legally
> privileged. If you are not an intended recipient or an authorized
> representative of an intended recipient, you are prohibited from using,
> copying or distributing the information in this e-mail or its attachments.
> If you have received this e-mail in error, please notify the sender
> immediately by return e-mail and delete all copies of this message and any
> attachments. Thank you.
>
> _______________________________________________
> Roll mailing list
> Roll@ietf.org
> https://www.ietf.org/mailman/listinfo/roll
>