Re: [Roll] DIS-modifications use cases; Re: FW: New Version Notification for draft-ietf-roll-dis-modifications-01.txt

[Rahul Jadhav <[e-mail]>]

On Mon, 24 Feb 2020 at 22:22, <[e-mail]> wrote:

> Dear Rollers,
>
> In preparation for the modification of the DIS (DODAG Information
> Solicitation), we are collecting the use cases.
> We want to make sure we understand all the requirements before crafting a
> solution.
> Georgios has kindly prepared a document on the ROLL GitHub repo.
> See a text rendition at
> https://github.com/roll-wg/roll-dis-modifications-use-cases/blob/master/dra
> ft-papadopoulos-roll-dis-modifications-use-cases.txt
> <https://github.com/roll-wg/roll-dis-modifications-use-cases/blob/master/draft-papadopoulos-roll-dis-modifications-use-cases.txt>


[RJ] Thanks Georgios. This surely helps. I am assuming that the use-cases
text will get merged in the dis-modifications draft.
One point mentioned in the use-cases draft is that unicast DIS can request
__specific__ metric information from the parent. Currently, the parent
sends the complete metric set to the child using unicast DIO. Wondering
whether we need this mechanism for sending specific metric info back to the
child node. The draft does not give a use-case for this. Anyways, this
would be discussed when the drafts get merged and sent to the group.

Currently, the document has two use cases:
> - a new node joins an established RPL network. The use case calls for a
> fairly quick confirmation that the node has joined with a good quality
> path. However, we don't want to reset the Trickle timers of all nearby
> routers and trigger broadcast, since the use case is that just one new
> node was added/replaced/rebooted.
> - another use case is that several nodes join at about the same time (e.g.
> electricity meters all reboot following power outage). We want the DIOs to
> be sent with broadcast so that all joining nodes benefit from them.
> The draft draft-thubert-roll-eliding-dio-information-03 has another
> request for modifying the DIS. We'll soon incorporate it into the use
> cases document.
>

[RJ] Another use-case is of "adjacency probing". While (I believe) no new
primitives need to be added, still the use-case is well-worth mentioning.
The RPL-observations draft points to this use-case and you can pick some
text from there.