Re: [Roll] Last Call: <draft-ietf-roll-trickle-mcast-06.txt> (Multicast Protocol for Low power and Lossy Networks (MPL)) to Proposed Standard

["Jonathan Hui (johui)" <[e-mail]>]

Hi Axel,

Thanks for your review and comments.  See my comments below:

On Feb 8, 2014, at 1:26 AM, Axel Colin de Verdière <[e-mail]> wrote:

> I've reviewed the draft, and I have a couple comments/questions if that's not too late:
> 
> - I don't see why MPL forwarders on the same link should have the same value for PROACTIVE_FORWARDING. It is now RECOMMENDED to make it so, but I don't see the rationale for this recommendation: on the opposite, I think it would allow some forwarders with less power restrictions to be more proactive than others.

Good point.  If there are no objections, I can remove this RECOMMENDED statement.

> - Isn't there a risk that only specifying SEED_SET_ENTRY_LIFETIME without any kind of hysteresis mechanism lead to old Data messages being reinjected in the network? For example, if an MPL forwarder A resets its Control Message trickle timer with a seed (S) close to expiration, there is a risk that a neighbor forwarder that has expired that seed interprets the Control Message as A having new Data messages from seed S, thus resetting its timer for this seed and potentially retransmitting the corresponding Data message(s).

The hysteresis is controlled using the DATA/CONTROL_MESSAGE_TIMER_EXPIRATIONS parameters.  The SEED_SET_ENTRY_LIFETIME should be much longer than these to help ensure that devices maintain state until the propagation has completed.

> - In section 9.2, it is unclear when the M flag should be cleared or set: why would it be arbitrarily cleared and not indicate whether or not this message's sequence number is the largest one received?

The M flag helps indicate whether a receiving node should reset its Trickle timer.  If the M flag is not set and the sequence number is lower than what is already known, there is no need to reset the Trickle timer.

—
Jonathan Hui

> Thank you,
> 
> Axel
> 
> Le 3 févr. 2014 à 11:23, peter van der Stok <[e-mail]> a écrit :
> 
>> I've reviewed draft-ietf-roll-trickle-mcast-06.txt.  The issues
>> raised during the WG last call concerning our applications, have been addressed adequately.
>> 
>> peter van der stok
>> 
>> Ralph Droms schreef op 2014-01-27 16:58:
>>> I've reviewed draft-ietf-roll-trickle-mcast-06.txt.  The issues I
>>> raised during the WG last call have been addressed and, in my opinion,
>>> the document is now ready for publication.
>>> - Ralph
>>> On Jan 24, 2014, at 3:16 PM 1/24/14, The IESG <[e-mail]> wrote:
>>>> The IESG has received a request from the Routing Over Low power and Lossy
>>>> networks WG (roll) to consider the following document:
>>>> - 'Multicast Protocol for Low power and Lossy Networks (MPL)'
>>>> <draft-ietf-roll-trickle-mcast-06.txt> as Proposed Standard
>>>> This is a second last call, the first one having been abandoned to send
>>>> the document back to the working group. But the latest revision addresses
>>>> comments that were received during the first last call.
>>>> The IESG plans to make a decision in the next few weeks, and solicits
>>>> final comments on this action. Please send substantive comments to the
>>>> [e-mail] mailing lists by 2014-02-07. Exceptionally, comments may be
>>>> sent to [e-mail] instead. In either case, please retain the
>>>> beginning of the Subject line to allow automated sorting.
>>>> Abstract
>>>> This document specifies the Multicast Protocol for Low power and
>>>> Lossy Networks (MPL) that provides IPv6 multicast forwarding in
>>>> constrained networks.  MPL avoids the need to construct or maintain
>>>> any multicast forwarding topology, disseminating messages to all MPL
>>>> Forwarders in an MPL Domain.  MPL uses the Trickle algorithm to
>>>> manage message transmissions for both control and data-plane
>>>> messages.  Different Trickle parameter configurations allow MPL to
>>>> trade between dissemination latency and transmission efficiency.
>>>> The file can be obtained via
>>>> http://datatracker.ietf.org/doc/draft-ietf-roll-trickle-mcast/
>>>> IESG discussion can be tracked via
>>>> http://datatracker.ietf.org/doc/draft-ietf-roll-trickle-mcast/ballot/
>>>> The following IPR Declarations may be related to this I-D:
>>>> http://datatracker.ietf.org/ipr/1858/
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