Re: [6tisch] Intention for draft-thubert-roll-forwarding-frags

"Pascal Thubert (pthubert)" <pthubert@cisco.com> Fri, 07 February 2014 08:48 UTC

From: "Pascal Thubert (pthubert)" <pthubert@cisco.com>
To: Michael Richardson <mcr+ietf@sandelman.ca>
Thread-Topic: Intention for draft-thubert-roll-forwarding-frags
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Date: Fri, 07 Feb 2014 08:48:31 +0000
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Cc: roll <roll@ietf.org>, Ines Robles <mariainesrobles@googlemail.com>, "6tisch@ietf.org" <6tisch@ietf.org>, "Jonathan Hui (johui)" <johui@cisco.com>
Subject: Re: [6tisch] Intention for draft-thubert-roll-forwarding-frags
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Hello Michael:

There are really 2 pieces in the draft, the 'trick' to forward a fragment and that can be implemented independently and transparently by every node, so there is no need for standardization and I could go ahead with an informational personal submission to the RFC editor - better have an RFC number than a lost in space personal submission.

And then there is the capability to retry and do flow control over fragment on a multihop forwarding plane. Forwarding fragments has this side effect that 1 hop ARQ in the middle of a multihop forwarding plane does not let the fragment source know that a fragment was abandoned somewhere on the way. Incomplete packets are a bad idea in a constrained node. Whether it is a good idea to protect fragments end-to -end over the multihop LLN as opposed *or* on top of every hop is debatable. Carsten opposes, and there were a number of other knee-jerk reactions. But we need a people who understand forwarding and transport to make the decision.

FYI, small frames are here to stay, even though 802.15.4g is heavily used in smartgrid applciations; classical 15.4 2006 is still the base of industrial WSN protocols and, BTW, of 6TiSCH.

Cheers,

Pascal

> -----Original Message-----
> From: mcr@sandelman.ca [mailto:mcr@sandelman.ca] On Behalf Of Michael
> Richardson
> Sent: jeudi 6 février 2014 17:44
> To: Pascal Thubert (pthubert)
> Cc: Ines Robles; Jonathan Hui (johui); roll
> Subject: Re: Intention for draft-thubert-roll-forwarding-frags
> 
> 
> Pascal Thubert (pthubert) <pthubert@cisco.com> wrote:
>     > We presented the work at 6lo, but there was a mitigated reception.
> 
>     > Carsten in particular opposed the work, and complained that it moved
> places,
>     > plus has doubts about the retry mechanism.
> 
>     > Would you wish ROLL to continue that work?
> 
> We are not looking for new things, but rather trying to make sure that we
> haven't missed or ignored any relevant new work.  Some times a draft is written
> just to explain an idea, and that it doesn't need to go anywhere.
> 
> --
> Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works
> IETF ROLL WG co-chair.    http://datatracker.ietf.org/wg/roll/charter/

Re: [6tisch] Intention for draft-thubert-roll-for… Pascal Thubert (pthubert)
Re: [6tisch] [Roll] Intention for draft-thubert-r… Carsten Bormann
Re: [6tisch] [Roll] Intention for draft-thubert-r… Michael Richardson