Re: [Roll] [6lo] Source-Routed Multicast

Michael Richardson <> Tue, 04 November 2014 02:18 UTC

Return-Path: <>
Received: from localhost ( []) by (Postfix) with ESMTP id 9CF281A1BCE; Mon, 3 Nov 2014 18:18:19 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.495
X-Spam-Status: No, score=-2.495 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RP_MATCHES_RCVD=-0.594, SPF_PASS=-0.001] autolearn=ham
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 5B71E_waDL5p; Mon, 3 Nov 2014 18:18:18 -0800 (PST)
Received: from ( [IPv6:2607:f0b0:f:3:216:3eff:fe7c:d1f3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 2CD291A1BBD; Mon, 3 Nov 2014 18:18:18 -0800 (PST)
Received: from ( [IPv6:2607:f0b0:f:2::247]) by (Postfix) with ESMTP id 9A95920028; Mon, 3 Nov 2014 21:19:54 -0500 (EST)
Received: by (Postfix, from userid 179) id 12933637F4; Mon, 3 Nov 2014 21:18:16 -0500 (EST)
Received: from (localhost []) by (Postfix) with ESMTP id F1BA263740; Mon, 3 Nov 2014 21:18:16 -0500 (EST)
From: Michael Richardson <>
To: Carsten Bormann <>
In-Reply-To: <>
References: <>
X-Mailer: MH-E 8.2; nmh 1.3-dev; GNU Emacs 23.4.1
X-Face: $\n1pF)h^`}$H>Hk{L"x@)JS7<%Az}5RyS@k9X%29-lHB$Ti.V>2bi.~ehC0; <'$9xN5Ub# z!G,p`nR&p7Fz@^UXIn156S8.~^@MJ*mMsD7=QFeq%AL4m<nPbLgmtKK-5dC@#:k
MIME-Version: 1.0
Content-Type: multipart/signed; boundary="=-=-="; micalg="pgp-sha1"; protocol="application/pgp-signature"
Date: Mon, 03 Nov 2014 21:18:16 -0500
Message-ID: <>
Subject: Re: [Roll] [6lo] Source-Routed Multicast
X-Mailman-Version: 2.1.15
Precedence: list
Reply-To: Routing Over Low power and Lossy networks <>
List-Id: Routing Over Low power and Lossy networks <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Tue, 04 Nov 2014 02:18:19 -0000

Carsten Bormann <> wrote:
    > In Hawaii, there will be a BOF about a multicast forwarding control
    > scheme where a router on the way prefixes a multicast packet with a
    > special header that tells downtree routers where to forward the
    > multicast — Bit Index Explicit Replication, or BIER.

    > While BIER appears to be very focused on a carrier or datacenter
    > perspective (see draft-kumar-bier-use-cases and the other
    > draft-*-bier-*), there are applications in constrained node networks
    > that would benefit from source-routed multicast.

I take your point.

    > With its current focus, I don’t think the BIER BOF itself is the right
    > place to have a technical discussion about this.

On the contrary, I think it is important at a BOF for this topic to be
brought up, if ONLY for it to be CLEARLY ruled out of scope.

    > There is no ROLL meeting in Hawaii.
    > The 6lo agenda is almost full.

ROLL would have to be rechartered to work on it; this is not to say that this
could not happen, but rather to say that even if we were meeting, discussing
it might be out of scope anyway.

Having said that, this thread is most welcome.

    > Should we do this in a side meeting?  (If we do this before Tuesday, we
    > can at least report in 6lo — if we do it on Sunday, we might even have
    > an opinion to air during the BIER BOF.)

I abhor "side meetings" --- either have a proper BOF in a room, or get a
bunch of beers is my opinion.

Michael Richardson <>, Sandelman Software Works
IETF ROLL WG co-chair.