Subject: Re: [Roll] Moving forward with the protocol work

From: <[email-masked]>
Date: Wed, 29 Jul 2009 10:43:33 +0200

Hi all,

First I want to recognize the work of the Design Team at producing the
RPL draft in a short time.
I like many ideas in the draft, one of them being the distinction
between building a structure, and routing on top of this structure
(obviously the structure can advantageously be made to closely match the
dominant traffic, such as convergecast).
In the current version of the draft, I reckon there are still items that
are debatable (how much of loop avoidance vs loop detection, and what
algorithms), or even missing. Good P2P routing is certainly a missing
one.
As a personal opinion, I trust the whole WG, including obviously the DT,
to come to a reasonnable and viable solution to this issue, especially
in the situation where the spatial density of communicating pairs is
limited, which is my understanding of LLN requirements.
At this point, I don't see that _not_ adopting the draft as a WG
document would accelerate or improve the situation in any way.
I therefore support the adoption of the RPL draft as a Working Group
document.

Dominique

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Message: 1
Date: Tue, 28 Jul 2009 18:34:24 +0200
From: JP Vasseur <[email-masked]>
Subject: [Roll] Moving forward with the protocol work
To: ROLL WG <[email-masked]>
Message-ID: <[email-masked]>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes

Dear WG,

First of all, thanks for all the time and energy you all have devoted
during the past few weeks on the protocol work. There was excellent
followup discussion at the physical WG meeting.

To the question "Do you think that RPL provides an adequate foundation
for the ROLL routing protocol work", there was clearly a good consensus
in the WG meeting. It was also recognized there are still several open
issues for which we WILL need help from many WG contributors, including
the authors of other documents.

Could you please confirm (or not) the adoption of draft-dt-roll-rpl-01
as a WG document ?

Then we will of course move to the next step.

Thanks,

JP and David

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From: "Ryusuke Masuoka" <[email-masked]>
Date: Wed, 29 Jul 2009 07:23:28 -0400

Hi, 

Thank you very much for letting us present DADR at 
the ROLL meeting yesterday (7/28). 

I have to apologize for giving you misinformation
about DADR during one of Q&A's and let me provide 
you the correct information. 

It is about data retention at a node. The data is 
retained at the node until it is made sure the data
is sent to the next hop (through ACK). However, the 
data is dropped and will NOT be kept at the node 
after it is made sure that the data 
is transmitted to the next hop. Only its packet ID
is kept for some period for loop detection and 
backtracking purposes. When the data returns to the
node for some reason (and the node knows it because 
it keeps packet IDs for some time), the node will use the newly 
received data to forward to other nodes if necessary. 

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This is probably preaching to the quire, but data reachability 
is one of the most important requirements for our DADR implementation. 
Some applications such as a smart metering need a stable operation 
of the social infrastructure to have customer confidence and 
there is financial aspect tied directly into data reachability. 
In such applications, we are typically required to guarantee 
data reachability from hundreds of nodes to a gateway within 
a very narrow time window. 

It may be of Japanese culture, but customers generally give
very stringent requirements and expect implementers to take
quite large responsibility. 

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Regards,

Ryu