Re: [Roll] updating DAO caches (was Re: Something to ADD)

[JP Vasseur <jvasseur at cisco.com>]

On Nov 20, 2009, at 8:38 PM, Michael Richardson wrote:

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> > > > > > "Jerald" == Jerald P Martocci <Jerald.P.Martocci at jci.com> writes:
>    Jerald> As probably the strongest proponent of the P2P requirement
>    Jerald> on this mailing list, I will readily admit that even in
>    Jerald> building control only about 25% of the router nodes need to
>    Jerald> pass intra-LLN P2P messages.  As I understand the DAO
>
> 1/4 of the nodes need P2P messages, but how much traffic does that
> represent?  Is it a big percentage of overall traffic?  Does it have
> particular characteristics that make a trip through the root bad
> (i.e. latency)
>
>    Jerald> So yes, I think we either need to design outward traffic
>    Jerald> into the DAG at the same level as we do inward traffic; or
>    Jerald> devise an on-demand scheme where a node can easily
>    Jerald> 'discover' another node in the DAG as needed. Richard's
>    Jerald> comment below is profound saying that right now  
> establishing
>    Jerald> a good outward link is a matter of luck, not design.
>
> When you say "discover", I think you mean:
>     discover a path through cousin nodes that avoids the root
>
> I too, would like to have this.
>
> I think that this could be a different protocol --- that it could
> leverage the communication used by the DAG to implement some kind of
> flood-fill algorithm to learn specific P2P routes that are important.

Let's first figure out if we need any other mechanisms beyond what we  
have.
You might gae notice the presence of route-tag to tag important  
routes, this
could be used to improve P2P path but let's first determine if we need  
anything
more first.

> I think the constraints of least-capable nodes excludes this from the
> base protocol -- but it's really want I think I care about.
>
> - --
> ]       He who is tired of Weird Al is tired of life!           |   
> firewalls  [
> ]   Michael Richardson, Sandelman Software Works, Ottawa, ON    |net  
> architect[
> ] mcr at sandelman.ottawa.on.ca http://www.sandelman.ottawa.on.ca/ | 
> device driver[
>   Kyoto Plus: watch the video <http://www.youtube.com/watch?v=kzx1ycLXQSE 
> >
> 	               then sign the petition.
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