From: "Pascal Thubert (pthubert)" <pthubert@cisco.com>
To: Carsten Bormann <cabo@tzi.org>
Thread-Topic: [6lo] [6tisch] Fwd: Comparison of 6lo-rpl drafts
Thread-Index: AQHP0kJzH1qZ2czsj0ybHQLexU1vAZwE7hTQ
Date: Wed, 17 Sep 2014 07:48:40 +0000
Deferred-Delivery: Wed, 17 Sep 2014 07:48:00 +0000
Message-ID: <E045AECD98228444A58C61C200AE1BD842DC5639@xmb-rcd-x01.cisco.com>
References: <CAH=LnKQDPf_-Tw7BODF03PKYkLXjLCSR9RAtd-x9-ha-c80Hrg@mail.gmail.com>
 <037472BD-E257-4561-8A07-988039DD4641@nestlabs.com>
 <CAMsDxWTHrgDLopT1Oz93xAuCyimAADmudBj71PTiHgCAj28CPg@mail.gmail.com>
 <E045AECD98228444A58C61C200AE1BD842DC5072@xmb-rcd-x01.cisco.com>
 <2992BA1F-147C-4652-B713-D2F31F45F74F@tzi.org>
In-Reply-To: <2992BA1F-147C-4652-B713-D2F31F45F74F@tzi.org>
Accept-Language: fr-FR, en-US
Content-Language: en-US
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: http://mailarchive.ietf.org/arch/msg/roll/u7iM6NXcilzGgDkqjg06QK09Tn8
Cc: "6tisch@ietf.org" <6tisch@ietf.org>,
 Routing Over Low power and Lossy networks <roll@ietf.org>,
 "6lo@ietf.org" <6lo@ietf.org>
Subject: Re: [Roll] [6lo] [6tisch] Fwd: Comparison of 6lo-rpl drafts
Precedence: list
Reply-To: Routing Over Low power and Lossy networks <roll@ietf.org>

Hello Carsten:

The split and domain-dependent use of the Flow Label field was still on the=
 table in the RFC 6437 discussions. This was rejected as a general rule but=
 we still need an exception to RFC 6437 for LLNs so let us see what we get =
there.

I can still agree with you to progress on a 6lo NHC proposal and produce th=
e best personal submission we can for WG evaluation. This in turn does not =
mean that 6lo will adopt the work or that ROLL will favor that option.=20

I suggest we focus discussions on the relevant MLs:
- 6MAN on whether we can avoid having to set and/or carry a field of random=
ized 20 bits in the LLN  then eventually rewrite it for LLN purpose
- ROLL to decide whether to use a ROLL solution (based on FL is the only on=
e on the table) or wait for 6lo to deliver
- 6Lo to decide whether and how to compress the RPL option (3 proposals on =
the table)

In any case copying 6TiSCH, which depends on the overall result to deliver =
the minimal draft, is a good idea.

Cheers,

Pascal


> -----Original Message-----
> From: Carsten Bormann [mailto:cabo@tzi.org]
> Sent: mercredi 17 septembre 2014 08:42
> To: Pascal Thubert (pthubert)
> Cc: 6tisch@ietf.org; 6lo@ietf.org
> Subject: Re: [6lo] [6tisch] Fwd: Comparison of 6lo-rpl drafts
>=20
> On 17 Sep 2014, at 07:46, Pascal Thubert (pthubert) <pthubert@cisco.com>
> wrote:
>=20
> > we have one free bit there
>=20
> It's not free, all 20 bits of the flow label are the flow label.
>=20
> (Again, we can argue dedicating the field that way in 1994, and keeping i=
t
> that way even while nibbling off bits for other uses, was bad protocol de=
sign,
> but that's water under the bridge.)
>=20
> I would prefer to stop wasting time on trying to hijack the flow label an=
d
> instead finish the work on an NHC representation.
>=20
> Gr=FC=DFe, Carsten