Re: [Roll] trickle-mcast-04 - Clarify scope value of 3 - subnet-local

["Ralph Droms (rdroms)" <[e-mail]>]

Michael...

On Jul 24, 2013, at 6:37 PM 7/24/13, Michael Richardson <[e-mail]> wrote:

> 
> Ralph Droms (rdroms) <[e-mail]> wrote:
>>> I would still like an explanation of why "subnet" is the wrong term.
>>> 
>>> When would scope-3 would be used such that it would not correspond to the set
>>> of links on which a "/64" (or other size) is used?
> 
>> Hm, I thought I responded but apparently not...
> 
>> This change to scope 0x03 is not just for MPL, so we don't know how
>> else it might be used in the future.
> 
> I understand, but perhaps it would be better, if, when another use case comes
> along, they write a document explaining why scope-3 is correct and
> non-conflicting with the trickle mcast use case.

I don't agree; in my opinion, it's better to release scope 0x03 from "reserved" state and give guidelines for its use.

Let's see how 6man WG consensus develops...

- Ralph

> 
>> Specific examples:
>> 1) two adjacent RPL domains, which do not share a prefix but are to be
>> considered as one realm for mDNS
> 
> I accept that this is a plausible scenario, but I believe that it
> presupposes a technical answer from the not-yet occured sdnsext BOF.
> sDNSext could well mandate a proxy solution where actual multicast packets do
> not cross that boundary.
> 
>> 2) one RPL domain and one other non-RPL subnet that are to be considered as one realm for mDNS
> 
> Do you mean, in fact, one LLN and another non-LLN technology, which have MPL
> capable routers connecting them?
> 
> I write it this way, because I think that there is a belief that RPL can only
> be used in LLNs, while the RPL architecture is very specifically for multiple
> link types, and I find it hard to imagine an MPL capable router which does
> not also speak RPL.
> 
> --
> Michael Richardson <[e-mail]>, Sandelman Software Works
> 
>