Re: [Roll] multicast & MLD on LLN

Michael Richardson <mcr+ietf@sandelman.ca> Wed, 15 October 2014 21:57 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Routing Over Low power and Lossy networks <roll@ietf.org>
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Date: Wed, 15 Oct 2014 17:56:59 -0400
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Cc: "IJsbrand Wijnands \(iwijnand\)" <ice@cisco.com>
Subject: Re: [Roll] multicast & MLD on LLN
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Kerry Lynn <kerlyn@ieee.org> wrote:
    > On Sat, Oct 11, 2014 at 2:39 AM, Carsten Bormann <cabo@tzi.org> wrote:

    >> Right, MLD is a host-router protocol.  Routers among them speak a
    >> routing protocol, so they wouldn’t exchange MLD.  (A RPL “leaf” is a
    >> router.)
    >>
    >> > Finally I'm looking at BIER see how their ideas could apply to LLNs…
    >>
    >> Yep.  We (TZI) have done (specified, implemented, analyzed) an
    >> efficient BIER-like multicast forwarding protocol for non-storing mode
    >> a while ago.
    >>

    > I admit to some confusion here.  Is (topology-free) MPL no longer the
    > default multicast forwarding protocol for LLN?

I don't know anything about BIER really... MPL is still the default at this point.
(proceedural delays getting trickle-mcast out, not-with-standing)
My take on the conversation is that BIER has some kind of helper node that
unicasts everything out as appropriate.

--
Michael Richardson <mcr+IETF@sandelman.ca>ca>, Sandelman Software Works
IETF ROLL WG co-chair.    http://datatracker.ietf.org/wg/roll/charter/