Re: [Roll] Last Call: <draft-ietf-roll-trickle-mcast-05.txt> (Multicast Protocol for Low power and Lossy Networks (MPL)) to Proposed Standard

[Robert Cragie <[e-mail]>]

I would propose adding the language to draft-ietf-roll-trickle-mcast. 
There doesn't seem much point to doing another "world's shortest RFC".

Here's an attempt at combining Ralph's text with the terminology in the 
draft:

=================
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 where 
the MPL Domain Address is 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 defined according to the 
underlying network technology; for example, when used in an 
IP-over-IEEE802.15.4 network, Realm-Local scope is defined to include 
the set of MPL Interfaces sharing a PAN ID.

An MPL Forwarder MAY participate in an MPL Domain where the MPL Domain 
Address uses a scope value of 4 (Admin-Local) 
[I-D.droms-6man-multicast-scopes]. When used with MPL, Admin-Local scope 
can be used in deployments that use administratively defined scopes that 
cover, for example, subnets based on different underlying network 
technologies.
=================

Robert
On 11/10/2013 18:09, Ralph Droms wrote:
> draft-ietf-roll-trickle-mcast-05 and draft-ietf-6man-multicast-scopes-00 are in conflict with each other.
>
> >From draft-ietf-roll-trickle-mcast-05:
>
>     When
>     used with MPL, Realm-Local scope is administratively defined and used
>     to define the boundaries of multicast message dissemination by MPL.
>
> >From draft-ietf-6man-multicast-scopes-00:
>
>     Realm-Local scope is the largest scope that is automatically
>     configured, i.e., automatically derived from physical
>     connectivity or other, non-multicast-related configuration.
>
> Specifically, "administratively defined" seems to me to be in direct
> conflict with "automatically configured".
>
> I suggest fixing the problem with two updates.  First, the definition
> of "scop 3" in an IP-over-IEEE802.15.4 needs to be published, based on
> this text from draft-ietf-6man-multicast-scopes-00:
>
>     The definition of any Realm-Local scope for a particular network
>     technology should be published in an RFC.
>
> I suggest:
>
>     When used in an IP-over-IEEE802.15.4 network, "scop 3" is defined
>     to include all interfaces sharing a PAN ID.
>
> This text could be added to draft-ietf-roll-trickle-mcast-05, or to
> draft-ietf-6man-multicast-scopes-00 or published separately in yet
> another "world's shortest RFC".
>
> Second, draft-ietf-roll-trickle-mcast-05 should be changed to read:
>
>     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].
>
> As a further refinement, I suggest text be added to
> draft-ietf-roll-trickle-mcast-05 to the effect of:
>
>     "scop 4" can also be used with MPL to cover deployments that use
>     administratively defined scopes that cover, for example, subnets
>     based on different underlying network technologies.
>
> - Ralph
>
> PS I originally posted about this issue to the rool WG mailing list:
> http://www.ietf.org/mail-archive/web/roll/current/msg08188.html.
> After a discussion with Kerry Lynn, I made a change to the definition
> of scop 3 for IEEE802.15.4.
> _______________________________________________
> Roll mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/roll
>