Re: [Roll] New Version Notification for draft-thubert-roll-forwarding-frags-01.txt

Hi Pascal,

I may need to discuss to know my interest, or to understand. Does this
protocol have interact with RPL or its information? The title is LLN
forwarding but the content is about 6LowPan, is this work better fitted in
6LoWPAN WG than ROLL?

AB

On Mon, Feb 25, 2013 at 10:58 AM, Pascal Thubert (pthubert) <
pthubert@cisco.com> wrote:

> Dear WG:
>
> As you know well, 6LoWPAN will fragment packets that are too wide for the
> MTU, which is likely to happen in a number of cases, unless the 802.15.4g
> MAC is used.
>
> As a consequence, in a route-over RPL subnet, a large packet must be
> reassembled at each hop to be routed and fragmented again.
>
> Streamlining the fragments will improve latency, and will save memory and
> CPU in the intermediate nodes.
>
> This draft enables the forwarding of fragments, which selective
> acknowledgement and flow control capabilities, end to end over the LLN.
>
> Upon a private request, I resubmitted the draft with a simplification,
> that is the removal of en encoding that would compress the acknowledgement
> bitmap.
>
> I also restored some text about Congestion notification, in order to
> validate the need with the group.
>
> Please let the authors know if you have interest in pursuing this work,
>
> Pascal
>
>
> -----Original Message-----
> From: internet-drafts@ietf.org [mailto:internet-drafts@ietf.org]
> Sent: lundi 25 février 2013 11:42
> To: Pascal Thubert (pthubert)
> Cc: Jonathan Hui (johui)
> Subject: New Version Notification for
> draft-thubert-roll-forwarding-frags-01.txt
>
>
> A new version of I-D, draft-thubert-roll-forwarding-frags-01.txt
> has been successfully submitted by Pascal Thubert and posted to the IETF
> repository.
>
> Filename:        draft-thubert-roll-forwarding-frags
> Revision:        01
> Title:           LLN Fragment Forwarding and Recovery
> Creation date:   2013-02-25
> Group:           Individual Submission
> Number of pages: 16
> URL:
> http://www.ietf.org/internet-drafts/draft-thubert-roll-forwarding-frags-01.txt
> Status:
> http://datatracker.ietf.org/doc/draft-thubert-roll-forwarding-frags
> Htmlized:
> http://tools.ietf.org/html/draft-thubert-roll-forwarding-frags-01
> Diff:
> http://www.ietf.org/rfcdiff?url2=draft-thubert-roll-forwarding-frags-01
>
> Abstract:
>    In order to be routed, a fragmented packet must be reassembled at
>    every hop of a multihop link where lower layer fragmentation occurs.
>    Considering that the IPv6 minimum MTU is 1280 bytes and that an an
>    802.15.4 frame can have a payload limited to 74 bytes in the worst
>    case, a packet might end up fragmented into as many as 18 fragments
>    at the 6LoWPAN shim layer.  If a single one of those fragments is
>    lost in transmission, all fragments must be resent, further
>    contributing to the congestion that might have caused the initial
>    packet loss.  This draft introduces a simple protocol to forward and
>    recover individual fragments that might be lost over multiple hops
>    between 6LoWPAN endpoints.
>
>
>
>
> The IETF Secretariat
>
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