Re: [Roll] dinner consensus on trickle-mcast and multicast-scopes

Ralph Droms <rdroms.ietf@gmail.com> Sun, 10 November 2013 15:02 UTC

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From: Ralph Droms <rdroms.ietf@gmail.com>
In-Reply-To: <5662.1383943492@sandelman.ca>
Date: Sun, 10 Nov 2013 09:02:26 -0600
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To: Routing Over Low power and Lossy networks <roll@ietf.org>, "ipv6@ietf.org List IPv6" <ipv6@ietf.org>
Subject: Re: [Roll] dinner consensus on trickle-mcast and multicast-scopes
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Reply-To: Routing Over Low power and Lossy networks <roll@ietf.org>

On Nov 8, 2013, at 2:44 PM 11/8/13, Michael Richardson <mcr@sandelman.ca> wrote:

> 
> (I didn't have time to write a shorter note)
> (Resending because I got the 6man list address wrong. Wish there was an alias)
> 
> glossary for 6man readers:
>      RPL = ROLL RFC6550 mesh-over routing protocol.
>      MPL = ROLL draft-ietf-trickle-mcast multicast distribution
>            protocol.
> 
> This email is a bit long, but represents what I believe was the
> consensus that was arrived at by a number of ROLL WG ID authors, some
> Zigbee IP experts, and Ralph.  This consensus was arrived at slowly
> over Tuesday night and Wednesday, and was brought to you by the letters
> B and I.  
> 
> I will start with the executive summary:
> 
> 1) there are some minor tweaks necessary to trickle-mcast to make
>   it consistent with multicast-scopes, and to indicate that 
>   encapsulation in scopes 4 and 5 are appropriate for some use cases

Thanks, Michael, for writing up the discussion that led to the conclusions in your executive summary.

Here is my summary of what needs to be changed in draft-ietf-trickle-mcast:

In section 4.1:

OLD:

   By default, an MPL Forwarder SHOULD participate in an MPL Domain
   identified by the ALL_MPL_FORWARDERS multicast address with a scope
   value of 3 (Realm-Local) [I-D.droms-6man-multicast-scopes].  When
   used with MPL, Realm-Local scope is administratively defined and used
   to define the boundaries of multicast message dissemination by MPL.

NEW:

   By default, an MPL Forwarder SHOULD participate in an MPL Domain
   identified by the ALL_MPL_FORWARDERS multicast address with a scope
   value of 3 (Realm-Local) [I-D.ietf-6man-multicast-scopes].    When
   used with MPL, Realm-Local scope is defined according to the
   underlying network technology; for example, [cite the
   IP-over-IEEE802.15.4 definition].

   Admin-Local scope (scop value 4) and Site-Local scope (scop value
   5) can also be used with MPL in deployments that use
   administratively defined scopes that cover, for example, multiple
   subnets based on different underlying network technologies.

where "the IP-over-IEEE802.15.4 definition" is text to be published elsewhere (as determined by the 6man WG) as an update to RFC 4291 that defines scop 3 for IEEE802.15.4 mesh networks.

> 2) that the text in multicast-scopes that speaks of "administratively
>   defined" is confusing to many, and a suggestion on different text
>   will be posted in a reply to this email.

To be precise, RFC 4291 and (in updating RFC 4291) both refer to "administratively configured" rather than "administratively defined".  RFC 4007 refers to "zones [...] defined and configured by network administrators".  If there is consensus in the 6man WG that "administratively configured" and the text from RFC 4007 needs to be clarified, the clarification should apply to RFC 4291 and RFC 4007.  That clarification could be included in draft-ietf-6man-multicast-scopes, as part of that document's updates to RFC 4291 and RFC 4007.

> [...]

> --
> Michael Richardson
> -on the road-

- Ralph

[Roll] dinner consensus on trickle-mcast and mult… Michael Richardson
[Roll] dinner consensus on trickle-mcast and mult… Michael Richardson
Re: [Roll] dinner consensus on trickle-mcast and … Kerry Lynn
Re: [Roll] dinner consensus on trickle-mcast and … Ralph Droms